Mimeo Cassette Interface Assembly and Operations Guide
By Mike Willegal www.willegal.net version 0.17 CAUTION!!!
Incorrect assembly or connecting of the Mimeo Cassette Interface can cause fatal damage to the interface and/or the motherboard. Double and triple check your connections before powering on. Pay special attention to orientation of the card when you plug it into the motherboards expansion slot. Plugging it in backwards will result in damage to the card and/or motherboard.

Forward

In the mid 1970s, around the time the Apple 1 was developed, the only reasonably affordable interface for home computer hobbyist was repurposing an ordinary cassette recorder as a data storage device. Soon after the introduction of the Apple 1, Apple Computer released the Apple Cassette Interface (ACI) for the Apple 1. This small card had a list price of $75 and turned out to be the only peripheral card that Apple ever released for the Apple 1. The Mimeo Cassette Interface is a clone of Apples original ACI, duplicating the form, fit and function of the original ACI in exacting detail. This manual refers to the board as the ACI, since that is the name Apple used and for all intents and purposes the implementations and operation are identical.

Reliability

Reliability of the ACI card, in its stock form, is not very good by 21st century standards. Apple made improvements to the cassette interface circuit when it came out with the Apple II. I have spent considerable effort looking for improvements in reliability, without altering the design of the original ACI printed circuit board. In the end, I have found three items that can help with reliability, Two of these involve changing component values. I am providing parts that can used to build the board with either original component values or with components that will improve reliability. Because of the reliability problems with the original design, I recommend building this kit with the components that improve reliability. Look and feel of the board is not affected but reliability is improved quite a bit. Even with these changes, reliability is not perfect, but the system will be more reliable. The third reliability improvement I recommend, is using an Apple recommended cassette recorder. I have had great difficulty with a different vintage cassette recorder that works quite well with an Apple II. The good news is that the original Apple recommended recorder happens to remain on the market. The is a Panasonic RQ2102. There may be other cassette recorders that perform as well or better than the RQ2102, but I dont have the time or resources to investigate the possibilities.
Chapter 1 Assemble Components, Tools, and Equipment
Recommended Tools and Equipment
Quality soldering station - I use a Weller WES51. Whatever you use, I recommend that it has some kind of temperature controlled tip. This will help prevent damage to the PCB when soldering. Soldering irons that do not have a temperature controlled tip can overheat and damage the PCB or component being soldered Solder - use quality solder - thinner solder is vastly easier to work with than fat solder. The fat stuff sold at hardware stores is not suitable for these sort of electronics projects Wire cutters for trimming component leads and cutting wire to length Wire strippers - for stripping ends of jumper wire Your favorite PCB cleaning agent - Isopropyl Alcohol will dissolve many kinds of soldering resin. Windex will also help with cleaning PCBs Ohm meter - to check for good connections and shorts Logic probe or oscilloscope handy if you are having trouble with bring up Your host computer schematics or hardware interfacing guide Direction for connecting to Mimeo 1 computers are provided in this manual

Additional Components (not included)
Cassette Recorder - I strongly recommend the Panasonic RQ-2102 Cassette Tapes - ordinary 30 or 60 minute tapes work well Two mono to mono 1/8 audio cables. One end plugs into the ACI, the other into jacks on the cassette recorder
Examine and identify all parts provided with the kit.
PART 16 pin socket 14 pin socket 8 pin socket LM311 74LS02 74LS10 74LS6301 - APPLE-A- APPLE-A4.01uF capacitor.1uF capacitor 100 ohm 3K resistor 10K resistor 10K 1% resistor 47K resistor DESCRIPTION For PROMs For 74LS parts For LM311 Voltage comparator Quad 2 input nor gate Triple 3 input nand gate Dual D type flip flop
Compare Received Components With Parts List

QUANTITY 1

PRESENT
Reliability improvement replacement for 74LS74 256x4 PROM - location A3 256x4 PROM - location A4 Input coupling capacitor Reliability improvement replacement for.01uF brown-black-brown Low part of voltage divider for tape output & current limiter for LED input monitor orange-black-red Voltage comparator feedback High part of voltage divider
brown-black-orange-gold for tape output
brown-black-orange-black-brown Voltage dividers for inputs to voltage comparator yellow-violet-orange brown-black-yellow LED Voltage comparator feedback Sense resistor for input monitor
100K resistor PCB MPS3704 RED LED Audio Jacks 1 jumper wire PARTS COUNT COUNT OF TYPES
Printed circuit board Sense transistors for input monitor LED Read level indicator Switchcraft #41 For jumpering from audio jack to PCB
Chapter 2 Solder In Components
The key thing here is to check orientation and make sure that you dont put the sockets or transistors in wrong. For the IC sockets, make sure that the parts are oriented correctly with pin 1 of the socket or chip near the edge of the PCB that contains the gold fingers. All components go on the front of the board (the side with the words Apple Cassette Interface 1 etched in copper. Make sure the socket or chip is fully seated. I accomplish this by resting the socket upside down on a small object with the board on top. The weight of the board should keep the socket or chip completely seated. Then tack down a couple of corner pins and recheck orientation and seating. Then finish soldering the rest of the pins. Take your time and enjoy the process, double checking orientation of devices as you go. The red or blue arrows indicate places to pay special attention when placing components.

Overview

back side of board Easiest way to do this is to use an ohm-meter to make sure that there is no connection between +5 volts, -12 volts and ground. The Ohm meter should show no connections between any of these nets. A convenient place to use to check for shorts, is this area on the back of the board (red arrows above).
Check for Power and Ground Shorts on PCB
3. Solder in All Components Except 1/8 Phono Jacks
front view of board (components are mounted on front side of board)
PART 16 pin socket 14 pin socket 8 pin socket DESCRIPTION A-3 and A-4 - pin 1 toward gold finger edge A-2, A-5, A-6 - pin 1 toward gold finger edge A-1 - pin 1 toward gold finger edge Input coupling capacitor - topmost device in row of components at A-1. Use.1uF (104) capacitor for better read reliability. Use.01uF (103) capacitor to exactly replicate original design. brown-black-brown brown-black-brown orange-black-red dip in row A-1 Top of row at A4 Next to gold fingers in row A1 Vertically mounted - left of 8 pin Top of row at A-QUANTITY 1 COMPLETE

capacitor

100 ohm 100 ohm 3K ohm 10K resistor 10K 1% resistor 47K resistor 100K resistor MPS3704 RED LED

brown-black-orange-gold

brown-black-orange-black-brown Four in a row below cap in row A-1 yellow-violet-orange brown-black-yellow Just above 8 pin dip in row A-1. just below two 1/8 jacks
Below two 1/8 jacks - flat side toward top of board (middle pin goes in hole closer to top of board) Long lead (anode) on right
After mounting the jacks, a short wire must be connected from tab on jack to PCB hole to connect read and write circuits to the jacks. See the illustrations above for locations.
PART DESCRIPTION The jack is mounted with the receptacle facing the front of the board (the same side as the components). Firmly tighten the nut, but not so tight that you risk damaging the PCB. Ground is through this connection. Cut two short lengths of wire that are long enough to reach from the tab on jack to the hole in the PCB. Strip ends of short wire. If you prefer, you can strip insulation from entire length of wire. Original ACIs had no insulation on these short lengths of wire. From the back of the board, solder one end to tab on jack and the other to the appropriate hole in the PCB. There are two tabs. Be sure to connect the wire to the tab that connects to the tip of the plug. QUANTITY COMPLETE

Install 1/8 Phono Jacks

Read and Write Jacks
Easiest way to do this is to use an ohm-meter to make sure that there is no direct connection between +5 volts, -12 volts and ground. With the resistors now soldered in, you should note about 9.6K ohms resistance between +5 volts and ground. -12 volts should have no connectivity with either +5 volts or ground.

Recheck for Power and Ground Shorts on PCB

PART LM311

Install ICs
DESCRIPTION 8 Pin Socket at A-1. Pin 1 toward gold fingers QUANTITY 2 COMPLETE

74LS74

14 Pin Socket at A-2. Pin 1 toward gold fingers. Use 74LS74 for original performance. Because of the floating inputs, a replacement 7474 is provided as an optional substitute part and should provide for slightly more reliable operation. A 7474 with floating inputs has more predictable behavior than a 74LS74. 16 Pin Socket at A-3. Pin 1 toward gold fingers. Prom is printed with APPLE A-3 on top of the package and has an A3 label on the bottom. 16 Pin Socket at A-4. Pin 1 toward gold fingers. Prom is printed with APPLE A-4 on top of the package and has an A4 label on the bottom. 14 Pin Socket at A-5. 14 Pin Socket at A-6. Pin 1 toward gold fingers. Pin 1 toward gold fingers.

PROM A-3

PROM A-4

74LS02 74LS10

Once soldering is complete, clean the back of PCB of excess flux and rosin. 90% or higher isopropyl alcohol. IPA will dissolve soldering resin. Note that the IPA will also remove the APPLE-AX printing on the PROMs so keep it away from these parts. Spray it on the back of the board and lightly scrub with a very soft brush that will not scratch the surface of the PCB. Soak up the IPA and contaminates with a clean soft cloth before the IPA evaporates in order to remove the by products of soldering. I have also discovered that Windex window cleaner can help remove the by-products from the soldering job. Removing contaminates is important as many kinds of rosins are corrosive. Let dry overnight. Position a fan to blow over the board to make sure that all remaining moisture evaporates. While the board is drying, you should carefully check your work for bad solder joints and solder bridges.
Clean PCB of Rosin and By-products of Soldering
Check Board for Solder Bridges and Cold Solder Joints
Chapter 3 Installation, Operation and Help
Completely read and understand the original Apple Cassette Interface Manual reproduced in appendix C for installation and operation instructions.
Installation and Operation
A good job of soldering the components into place should eliminate most if not all trouble. First step, in case of trouble, should be to check for bad solder joints or bridges. Refer to my Apple II repair page at www.willegal.net for some general troubleshooting hints. Feel free to send email to: mike@willegal.net if you run into difficulties.

Troubleshooting and Help

Appendix A - Using an iPod With the ACI
An iPod may be used in place of a cassette player with the ACI. Almost any iPod can be used for loading programs with the same cable that is used for reading from a cassette player. Programs must be put into AIFF format prior to loading. I have listed several programs already in that format on this web page: http://www.willegal.net/appleii/apple1-software.htm This same page has the source code for a UNIX shell program that will convert programs in Apple monitor format into AIFF files, so that you can convert your own programs to be loaded from a iPod. Writing to the iPod requires an iPod that supports microphone input, a special cable and an iPad application that uses a lossless recording format. A detailed write up on the process can be found here. http://www.apple1notes.com/Home/Notes.html

Appendix B Replica 1 Notes
At the time of this printing, the ACI has not been tested with a Briel Computer Systems Replica 1. Watch my blog at www.willegal.net/blog for updates on the results of this planned testing. I do not expect issues with this testing. If you do try it before I get the chance, remember that because the ACI requires -12volts, the Replica 1 must be powered by an ATX power supply. The Achatz replica does not have a provision for -12 volts, so the ACI will not work with that system.
Appendix C - Apples Original ACI Manual
Appendix C is a digitized reproduction of the original eight page Apple Cassette Interface manual. Fonts and layout are similar to the original, but not exact reproductions. Disregard warranty, address, phone number information - this data is left in place, so the complete manual is preserved. Unlike what the manual indicates, performance with various cassette recorders can vary from not functional to works pretty well. I use and recommend a Panasonic RQ-2102. The best volume setting for read operations on my recent production Panasonic RQ-2102 is around a 4. The LED circuit is configured to turn on at about 1.2 volts, which I have found, is too high a level for reliable data recovery. Dont rely on the LED to set your playback volume. Finally, it is my opinion is that the reliability of the ACI is not as good as the manual suggests. In fact, with the stock.01uF capacitor in place, I have experienced very unreliable operation. Operation improves substantially with the.1uF capacitor, which is why I have included it in the kit. Except for these points, the manual contains accurate and useful information for installation and operation of the ACI and should be read and understood prior to installing and operating your ACI.
Appendix D ACI Source Code Listing
Appendix D is the source code listing for the 256 byte PROM bank that exists on the ACI card.
APPLE-1 CASSETTE INTERFACE

INTRODUCTION

resulting in the inability to accurately read a tape that has been recorded on a different machine. However, if the same unit is used for both recording and reading, even the cheapest of cassette recorders will work reliably. Most tapes available in the $2-$4 category work well for data storage. You may experience an occasional tape which loses bits which is caused by severe oxide thickness variations on the tape and cannot be corrected. Special leaderless tapes need not be used as the ACI automatically transmits a ten second header of all ones before transmitting the data, which insures that the leader will have passed.
The Apple Cassette Interface [ACI] is a peripheral device for the Apple Computer which enables the user to store and retrieve information (data and programs) using a standard audio grade cassette recorder. The ACI attaches directly to the Apple Computer and jacks are provided on the ACI board to connect to the cassette recorder. The ACI reads and writes data at the rate of approximately 1500 baud (depending upon the data), All the ACI timing is done in software, resulting in extreme accuracy, no adjustments, and consistency between units.

TAPE RECORDERS & TAPE

JUMPERS

For operation of the ACI, a permanent jumpcr must be placed between R and C in the block select area of the main board (B9,10). This jumper from R which is connectcd to enable the ACI, to C se1ects the ACI when the 12th 4K block (C) is addressed. Also, for running Apple Basic in the 2nd 4K band of on-board memory, it is necessary to break the solder jumper between W and 1 and then jumper W to E. This moves the 2nd 4K bank from the 1 block to the E block, which is where Apple Basic resides.
Almost any cassette recorder will work well with the ACI. As a recommendation, we have found the least expensive (under $40) Panasonic to be very reliable and of good quality, although it is not equipped with a tape counter. which is useful (though not essential) for locating files within a tape. (An alternative method of discerning files is to record a voice identification between files.) Among the under $25 cassette recorders there may be variations in head alignment and internal electronics,
Install the ACI board into the connector on the main board with the components on the ACI board facing away from the main board (the jacks to the edge of the main board). SEE FIGURE 1. The system power should be OFF whenever installing or removing the ACI board. Install cables from the ACI jack marked TO TAPE to the recorder microphone input and from the ACI jack marked FROM TAPE to the recorder earphone output. One cable can be appropriately switched between the two paths if necessary.
The Cassette program is contained in two PROMS on the ACI board and runs at C100. When entered, the program should echo an *. The format for specifying the memory address ranges to be either stored (write) or deposited into (read) is identical to the standard monitor format: Beginning. End , suffixed with either a W (write) or an R (read). Execution will start following a carriage return (CR). The cassette program will return control to the system monitor upon completion of a read or write. Illegal characters (or the absence of characters) in the address line will return control to the system monitor without execution, following a carriage return.

INSTALLATION

USING THE ACI

MULTIPLE RANGES

The ACI is capable of reading and writing multiple address ranges. The format is: A.BW C.DW (R for read). Again, spaces are ignored. The ACI will write a ten second header, the first range, another header and the second range. 100.200W 300.500W will write a header, 100 in 200, a second header, and 300 to 500. When reading a multiple range tape. YOU MUST USE THE SAME ADDRESS INCREMENTS AS WERE USED IN WRITING THE TAPE. This does not mean the same absolute addresses, but rather the same increments.

The Cassette recorder output level should be set to where the LED on the ACI is just fully lit. Increase the level from zero until the LED glows fully. If you experience a bad read, try it a LITTLE higher. The LED indicator is operational even when the cassette program is not executing. and the level should be set prior to reading a tape, NOT during the reading of a tape.
The procedure for reading from a tape into memory is: C100R (RET) This enters the cassette program and should echo an * E000. EFFFR This will load the tape data into mem ory locations E000.EFFF. R denotes a read, and spaces are ignored. [Dont hit return yet.) Start the Tape Hit RETURNA carriage return will start execution of a read. The return can be hit immediately, however, it must be hit within 5 seconds after the start of tape motion. When the last location (EFFF in this example) has been loaded, the program will print a / and return control to the monitor. The procedure for a write is identical except the suffix W is substituted for R in the address line. For both read and write, the tape should always be moving before hitting the RETURN.
The ACI uses the technique of recording a whole cycle of either a 1kHz cycle (representing a one data bit) or a 2 kHz cycle (representing a zero data bit). Therefore, with an average data mix of ones and zero`s, data will be recorded at 1500 baud. A ten second header of all ones will automatically be recorded on the tape prior to memory data. This is to insure that the clear leader portion of the tape will have passed. See schematic for further details.

WARRANTY

Apple Computer Company hereby warrants each of its products, and all components therein contained, to be free from defects in materials and/or workmanship for a period of thirty (30) days from date of purchase. In the event of the occurrence of malfunction, or other indication of failure attributable directly to faulty workmanship and/or material, then, upon return of the product to the Apple Computer Company at 770 Welch Road, Palo Alto, California 94304 (postage prepaid), the Apple Computer Company will, at its option, repair or replace said products or components thereof, to whatever extent Apple Computer Company shall deem necessary, to restore said product to proper operating condition. All such repairs or replacements shall he rendered by Apple Computer Company without charge to the customer. The responsibilty for the failure of any Apple Computer product, or component thereof, which, at the discretion of the Apple Computer Company , shall have resulted either directly or indirectly from accident, abuse, or misapplication of the product, shall be assumed by the cutomer and the Apple Computer Company shall assume no liability as a consequence of such events under the terms of this warranty. While every effort, on the part of Apple Computer Company, is made to provide clear and accurate technical instruction on the use, implementation, and application of its products, the Apple Computer Company shall assume no liability in events which arise from the application of such technical instruction, nor shall the Apple Computer Company be held liable for the quality, interconnection, or application of periferal products, which may have been recommended by Apple Computer Company, but which have not been supplied as part of the product. This warranty contains and embodies the limits of responsibility of the Apple Computer Company with regard to its products, and no other liability is expressed, implied, or should be assumed by the purchaser, and in no event shall the Apple Computer Company be held liable for the loss of time, effort , or transportation costs, nor for loss of potential profits or other consequential losses which might arise from the purchase, assembly, use, application, or subsequent sale of the products of Apple Computer Company, nor from any instructions and/or mechanical information thereto related.

APPLE COMPUTER COMPANY 770 Welch Road, Suite 154 Palo Alto, California 94304 Phone:(415) 326-4248
------- FILE wozaci.asm LEVEL 1 PASS c200 PROCESSOR c200 ???? LIST ON 3 c200 ???? ;------------------------------------------------------------------------4 c200 ???? ; 5 c200 ???? ; The WOZ Apple Cassette Interface for the Apple c200 ???? ; Written by Steve Wozniak somewhere around c200 ???? ; 8 c200 ???? ;------------------------------------------------------------------------9 c200 ???? 10 c100 ORG $Ccc100 ;------------------------------------------------------------------------13 c100 ; Memory declaration 14 c100 ;------------------------------------------------------------------------15 cc24 HEX1L EQU $24 ;End address of dump block 17 c25 HEX1H EQU $c26 HEX2L EQU $26 ;Begin address of dump block 19 c27 HEX2H EQU $c28 SAVEINDEX EQU $28 ;Save index in input buffer 21 c29 LASTSTATE EQU $29 ;Last input state 22 cc00 IN EQU $0200 ;Input buffer 24 c100 cFLIP EQU $C000 ;Output flip-flop 25 c100 cTAPEIN EQU $C081 ;Tape input 26 c100 dKBD EQU $D010 ;PIA.A keyboard input 27 c100 dKBDCR EQU $D011 ;PIA.A keyboard control register 28 c100 ff 1a ESCAPE EQU $FF1A ;Escape back to monitor 29 c100 ff ef ECHO EQU $FFEF ;Echo character to terminal 30 cc100 ;------------------------------------------------------------------------32 c100 ; Constants 33 c100 ;------------------------------------------------------------------------34 cc8d CR EQU $8D ;Carriage Return 36 c9b ESC EQU $9B ;ASCII ESC 37 cc100 ;------------------------------------------------------------------------39 c100 ; Lets get started 40 c100 ;------------------------------------------------------------------------41 cc100 a9 aa WOZACI LDA #$AA ;Print the Tape prompt * 43 c10220 ef ff JSR ECHO 44 c105 a9 8d LDA #CR ;And drop the cursor one line 45 c10720 ef ff JSR ECHO 46 c10a 47 c10a a0 ff LDY #-1 ;Reset the input buffer index 48 c10c c8 NEXTCHAR INY 49 c10d ad 11 d0 KBDWAIT LDA KBDCR ;Wait for a key 50 c11010 fb BPL KBDWAIT ;Still no key! 51 cc112 ad 10 d0 LDA KBD ;Read key from keyboard 53 c STA IN,Y ;Save it into buffer 54 c11820 ef ff JSR ECHO ;And type it on the screen 55 c11b c9 9b CMP #ESC 56 c11d f0 e1 BEQ WOZACI ;Start from scratch if ESC! 57 c11f c9 8d CMP #CR 58 c121 d0 e9 BNE NEXTCHAR ;Read keys until CR 59 cc123 a2 ff LDX #-1 ;Initialize parse buffer pointer 61 c125
62 c125 ;------------------------------------------------------------------------63 c125 ; Start parsing first or a new tape command 64 c125 ;------------------------------------------------------------------------65 cc125 aNEXTCMD LDA #0 ;Clear begin and end values 67 c24 STA HEX1L 68 c25 STA HEX1H 69 c12b STA HEX2L 70 c12d STA HEX2H 71 c12f 72 c12f e8 NEXTCHR INX ;Increment input pointer 73 c130 bd LDA IN,X ;Get next char from input line 74 c133 c9 d2 CMP #$D2 ;Read command? R 75 c135 fBEQ READ ;Yes! 76 c137 c9 d7 CMP #$D7 ;Write command? W 77 c139 fBEQ WRITE ;Yes! (note: CY=1) 78 c13b c9 ae CMP #$AE ;Separator?. 79 c13d fBEQ SEP ;Yes! 80 c13f c9 8d CMP #CR ;End of line? 81 c141 fBEQ GOESC ;Escape to monitor! Were done 82 c143 c9 a0 CMP #$A0 ;Ignore spaces: 83 c145 f0 e8 BEQ NEXTCHR 84 c14749 b0 EOR #$B0 ;Map digits to 0-85 c149 c9 0a CMP #9+1 ;Is it a decimal digit? 86 c14b BCC DIG ;Yes! 87 c14dADC #$88 ;Map letter A-F to $FA-$FF 88 c14f c9 fa CMP #$FA ;Hex letter? 89 cad BCC WOZACI ;No! Character not hex! 90 cc153 0a DIG ASL ;Hex digit to MSD of A 92 c154 0a ASL 93 c155 0a ASL 94 c156 0a ASL 95 cc157 aLDY #4 ;Shift count 97 c159 0a HEXSHIFT ASL ;Hex digit left, MSB to carry 98 c15aROL HEX1L ;Rotate into LSD 99 c15cROL HEX1H ;Rotate into MSD 100 c15e 88 DEY ;Done 4 shifts? 101 c15f d0 f8 BNE HEXSHIFT ;No! Loop 102 c161 f0 cc BEQ NEXTCHR ;Handle next character 103 cc163 ;------------------------------------------------------------------------105 c163 ; Return to monitor, prints \ first 106 c163 ;------------------------------------------------------------------------107 cc1634c 1a ff GOESC JMP ESCAPE ;Escape back to monitor 109 cc166 ;------------------------------------------------------------------------111 c166 ; Separating. found. Copy HEX1 to Hex2. Doesnt clear HEX1!!! 112 c166 ;------------------------------------------------------------------------113 cc166 aSEP LDA HEX1L ;Copy hex value 1 to hex value c26 STA HEX2L 116 c16a aLDA HEX1H 117 c16c STA HEX2H 118 c16e b0 bf BCS NEXTCHR ;Always taken! 119 c170

182 183

c170 ;------------------------------------------------------------------------c170 ; Write a block of memory to tape c170 ;------------------------------------------------------------------------c170 c170 aWRITE LDA #64 ;Write 10 second header c17220 cc c1 JSR WHEADER c175 cWRNEXT DEY ;Compensate timing for extra work c176 aLDX #0 ;Get next byte to write c178 aLDA (HEX2L,X) c17a c17a aLDX #8*2 ;Shift 8 bits (decremented twice) c17c 0a WBITLOOP ASL ;Shift MSB to carry c17d20 db c1 JSR WRITEBIT ;Write this bit c180 d0 fa BNE WBITLOOP ;Do all 8 bits! c182 c18220 f1 c1 JSR INCADDR ;Increment address c185 a0 1e LDY #30 ;Compensate timer for extra work cec BCC WRNEXT ;Not done yet! Write next byte c189 c189 aRESTIDX LDX SAVEINDEX ;Restore index in input line c18b bBCS NEXTCMD ;Always taken! c18d c18d ;------------------------------------------------------------------------c18d ; Read from tape c18d ;------------------------------------------------------------------------c18d c18d20 bc c1 READ JSR FULLCYCLE ;Wait until full cycle is detected c190 aLDA #22 ;Introduce some delay to allow c19220 cc c1 JSR WHEADER ; the tape speed to stabilize c19520 bc c1 JSR FULLCYCLE ;Synchronize with full cycle c198 c198 a0 1f NOTSTART LDY #31 ;Try to detect the much shorter c19a20 bf c1 JSR CMPLEVEL ; start bit c19d b0 f9 BCS NOTSTART ;Start bit not detected yet! c19f c19f20 bf c1 JSR CMPLEVEL ;Wait for 2nd phase of start bit c1a2 c1a2 a0 3a LDY #58 ;Set threshold value in middle c1a4 aRDBYTE LDX #8 ;Receiver 8 bits c1a648 RDBIT PHA c1a720 bc c1 JSR FULLCYCLE ;Detect a full cycle c1aa68 PLA c1ab2a ROL ;Roll new bit into result c1ac aLDY #57 ;Set threshold value in middle c1ae ca DEX ;Decrement bit counter c1af d0 f5 BNE RDBIT ;Read next bit! c1b26 STA (HEX2L,X) ;Save new byte c1b3 c1b320 f1 c1 JSR INCADDR ;Increment address c1b6 aLDY #53 ;Compensate threshold with workload c1bea BCC RDBYTE ;Do next byte if not done yet! c1ba b0 cd BCS RESTIDX ;Always taken! Restore parse index c1bc c1bc20 bf c1 FULLCYCLE JSR CMPLEVEL ;Wait for two level changes c1bf 88 CMPLEVEL DEY ;Decrement time counter c1c0 ad 81 c0 LDA TAPEIN ;Get Tape In data c1c3 cCMP LASTSTATE ;Same as before? c1c5 f0 f8 BEQ CMPLEVEL ;Yes! c1c29 STA LASTSTATE ;Save new data c1c9 c1c9 cCPY #128 ;Compare threshold c1cb60 RTS c1cc

242 243

c1cc ;------------------------------------------------------------------------c1cc ; Write header to tape c1cc ; c1cc ; The header consists of an asymmetric cycle, starting with one phase of c1cc ; approximately (66+47)x5=565us, followed by a second phase of c1cc ; approximately (44+47)x5=455us. c1cc ; Total cycle duration is approximately 1020us ~ 1kHz. The actual c1cc ; frequencywill be a bit lower because of the additional workload between c1cc ; the twoloops. c1cc ; The header ends with a short phase of (30+47)x5=385us and a normal c1cc ; phase of (44+47)x5=455us. This start bit must be detected by the read c1cc ; routine to trigger the reading of the actual data. c1cc ;------------------------------------------------------------------------c1cc c1cc WHEADER STX SAVEINDEX ;Save index in input line c1ce aHCOUNT LDY #66 ;Extra long delay c1d020 e0 c1 JSR WDELAY ;CY is constantly 1, writing a 1 c1d3 d0 f9 BNE HCOUNT ;Do this 64 * 256 time! c1d569 fe ADC #-2 ;Decrement A (CY=1 all the time) c1d7 b0 f5 BCS HCOUNT ;Not all done! c1d9 a0 1e LDY #30 ;Write a final short bit (start) c1db ; c1db ;------------------------------------------------------------------------c1db ; Write a full bit cycle c1db ; c1db ; Upon entry Y contains a compensated value for the first phase of 0 c1db ; bit length. All subsequent loops dont have to be time compensated. c1db ;------------------------------------------------------------------------c1db c1db20 e0 c1 WRITEBIT JSR WDELAY ;Do two equal phases c1de a0 2c LDY #44 ;Load 250us counter - compensation c1e0 c1eWDELAY DEY ;Delay 250us (one phase of 2kHz) c1e1 d0 fd BNE WDELAY c1e05 BCC WRITE1 ;Write a 1 (2kHz) c1e5 c1e5 a0 2f LDY #47 ;Additional delay for 0 (1kHz) c1eWDELAY0 DEY ; (delay 250us) c1e8 d0 fd BNE WDELAY0 c1ea c1ea bc 00 c0 WRITE1 LDY FLIP,X ;Flip the output bit c1ed aLDY #41 ;Reload 250us cntr (compensation) c1ef ca DEX ;Decrement bit counter c1f060 RTS c1f1 c1f1 ;------------------------------------------------------------------------c1f1 ; Increment current address and compare with last address c1f1 ;------------------------------------------------------------------------c1f1 c1f1 aINCADDR LDA HEX2L ;Compare current address with c1f3 cCMP HEX1L ; end address c1f5 aLDA HEX2H c1f7 eSBC HEX1H c1f9 eINC HEX2L ;And increment current address c1fb dBNE NOCARRY ;No carry to MSB! c1fd eINC HEX2H c1ff60 NOCARRY RTS c200 c200 ;------------------------------------------------------------------------c200

Brain Board with Wozaniam Pack Assembly and Operations Guide
By Mike Willegal www.willegal.net version 5.1
Vintage computers should always be attended while powered up. Aging components in old computers can fail at any time in unpredictable and sometimes hazardous ways, including fire. Your house could burn down, or worse, if your vintage computer is left running without supervision. Incorrect assembly or connecting of the Brain Board can cause fatal damage to the interface and/or the motherboard. Double and triple check your connections before powering on. Pay special attention to orientation of the card when you plug it into the motherboards expansion slot. Plugging it in backwards will result in damage to the card and/or motherboard.

CAUTION!!!

CAUTION #2!!!

Contents

Brain Board Overview Chapter 1 Assemble Components, Tools, and Equipment Chapter 2 Building the Brain Board Chapter 3 Installation, Operation and Help Chapter 4 - Schematics Wozanium Pack Overview Chapter 1 - Wozanium Pack - Apple 1 Users Guide Chapter 2 - Wozanium Pack - Apple Cassette Interface Guide BB:1 BB:2 BB:4 BB:8 BB:14 WP:1 WP:2 WP:7
Chapter 3 - Using an iPod or PC With the Apple Cassette Interface WP:9 Chapter 4 - Wozanium Pack - Functional Description Chapter 5 - Wozanium Pack - Quick Start Guide WP:10 WP:16

Brain Board Overview

The brain board is a firmware board for your Apple II/Apple II plus or Apple IIe computer. The board uses inexpensive and readily available 27c128 or 27c256 PROMs. Because of the denser PROMs used, 6 sockets are replaced with one and the resulting size of the board is reduced to under 3 by 4 inches. The original Apple firmware board was able to replace motherboard ROM functionality with its own ROMs. This allowed an Apple II to have Applesoft in ROM or an Apple II plus to have Integer basic in ROM. A softswitch (flip-flop) is included which allows for switching between the firmware card and motherboard ROMs through software control. The board also includes a little known and seldom used capability that allows multiple firmware cards to coexist in the same system as long as they are in adjacent slots. Firmware cards were normally located in slot 0, but they could be located in any slot. Later on in time, a 16K ram (language) card was developed that had the same functionality, except the appropriate BASIC was loaded into the language card from disk when DOS was booted. The multiple card support was dropped. The base design of the Brain Board includes all the capability of the Applesoft/Integer Basic Firmware ROM board that Apple Computer released around 1978 including: switch for enable/disable a software controlled switch (soft switch) for changing between motherboard ROMs and firmware board ROMs jumper for enabling monitor ROM F8 - this was a solder pad jumper in the Apple design daisy chain enable functionality via DMA bus connections for multiple card support. In addition, I have added several enhancements in order to maximize usefulness of the board. The modified design will allow booting a ROM-less motherboard into DOS, which is not possible with the original firmware board 27C256 PROMs allow support of two complete ROM images on the Brain Board. Images of both Applesoft and Integer BASIC with matching monitors could be installed and used from the single PROM. An extra soft switch is used to select whether the high or low half of the PROM is in use. This soft switch can be configured by external switch, through software control or by jumper. The Apple II peripheral bus I/O select signal is connected to the lowest 256 bytes of the PROM bank that is currently selected by the bank select flip flop. I/O select is connected to a different address depending upon the slot the board is located in. Slot 0 does not have a I/O select signal, so this feature cannot be used if the Brain Board is installed in slot 0. The starting address for these 256 bytes is computed by multiplying 0x100 by the slot number and adding 0xC000. Thus slot 1 is 0xC100, slot 2 is 0xC200, etc.

Chapter 1 Assemble Components, Tools, and Equipment
Recommended Tools and Equipment
Quality soldering station - I use a Weller WES51. I recommend that whatever soldering iron you use, that it has some kind of temperature controlled tip. This will help prevent damage to the PCB when soldering. Soldering irons that do not have a temperature controlled tip can overheat and damage the PCB or component being soldered Solder - use quality solder - thinner solder is vastly easier to work with than fat solder. The fat stuff sold at hardware stores is not suitable for these sort of electronics projects. I have been using Qualitek 60/40 silver/lead with 3.3% flux.032 diameter (PN 50-30521). Note that lead is known to cause cancer and birth defects or other reproductive harm, so use with caution. Wire cutters for trimming component leads to length Your favorite PCB cleaning agent - Isopropyl Alcohol will dissolve many kinds of soldering resin. Windex will also help with cleaning PCBs Ohm meter - to check for good connections and shorts Logic probe or oscilloscope handy if you are having trouble with bring up Your Apple II computer schematics or hardware interfacing guide Direction for connecting to Apple II/IIplus/IIe computers are provided in this manual When using the Wozanium Rom image (Apple 1 emulation) , the Apple 1 operations and ACI manuals are helpful. The software sections of the Apple 1 operations manual along with the ACI manual are provided with the Brain Board
Additional Components (not included)
Cassette Recorder - I can recommend the Panasonic RQ-2102 Cassette Tapes - ordinary 30 or 60 minute tapes work well Two mono to mono 1/8 audio cables. One end plugs into the ACI, the other into jacks on the cassette recorder
Examine and identify all parts provided with the kit.
PART 28 pin wide dip socket 20 pin dip socket 16 pin dip socket 14 pin dip socket 74LS09 74LS11 74LS74 74LS138 74LS244 27C256.01uF capacitor 3K resistor 10K resistor DIP switch array DPSP switch PCB PARTS COUNT COUNT OF TYPES DESCRIPTION For 27C128 or 27C256 For 74LS244 For 74LS138

Overview

An Important Note About The Toggle Switch
back side of board The ground plane is the wide trace on the back of the board. The +5 volt plane is a similar trace on the front of the board. Easiest way to check for power ground shorts is to use an ohm-meter to make sure that there is no connection between +5 volts and ground. The Ohm meter should show no connection (or infinate resistance) between +5 volts and ground. A convenient place to check for shorts, is by using the pads of one of the six decoupling caps (blue arrows in the image above).
Check for Power and Ground Shorts on PCB
4. Solder in All Components
front view of board (components are mounted on front side of board) pin 1 indicatd by blue arrows
PART 28 pin socket 20 pin socket 16 pin socket 14 pin sockets DESCRIPTION B-4 - 27c256, pin 1 away from gold finger edge D-4 - 74LS244, pin 1 toward edge of board B-2 - 74LS138, pin1 away from gold finger edge A-3, A-4, B-1, D-2 - 74LS11, 74LS09(2) and 74LS74, pin 1 away from gold finger edge D-3 (2), A-1, A-3, A-4, B-4, C1 through C6. Decoupling capacitors.1uF. Orientation is not important. C-1, A-1 and A-4 orange-black-red Orientation is not important. At C-1 the 3K resistor goes between the two 10K resistors C-1(2), C-2, and A-2. brown-black-brown Orientation is not important. D-1 A-1 Important: read section 2 of this chapter before installing. QUANTITY COMPLETE

capacitors

3K ohm resistor 10K ohm resistor DIP switch array Reset control switch
Easiest way to do this is to use an ohm-meter to make sure that there is no short between +5 volts, and ground.
Recheck for Power and Ground Shorts on PCB
Follow pin 1 markings on board (small white dot in silk-screen and square pad in copper layer). ICs will be easier to insert, if the legs are bent to a angle that precisely aligns with the sockets. To do this, place the IC on its side on a hard flat surface. One set of pins will be on the surface and pointed towards you. Keeping the ICs legs held firmly down, carefully roll the chip toward you to slightly bend the chip leads just a bit and then repeat with the process with the chip flipped to its other side. Check for fit against socket and repeat accordingly. When stuffing chips into sockets, be careful that pins are not inadvertently bent underneath the chip, instead of going into the socket. If you do bend a pin, they can be usually be straightened with a small pliers, if you do it carefully. Pins will usually break, right where they connect with the chip case, so do not bend the pin any more than necessary, especially at the joint, where it mates with the case.

PART 74LS09 (2) DESCRIPTION 14 pin sockets at A-3 and B1 QUANTITY 2 COMPLETE

Install ICs

74LS74

14 pin socket at D-2.

74LS11

14 pin socket a A-2

74LS138

16 pin socket at B-2

74LS244 27C256
20 pin socket at D-pin socket at B-3
Once soldering is complete, clean the back of PCB of excess flux and rosin. 90% or higher isopropyl alcohol. IPA will dissolve soldering resin. Note that the IPA will also remove the printing on the PROMs so keep it away from these parts. Spray it on the back of the board and lightly scrub with a very soft brush that will not scratch the surface of the PCB. Soak up the IPA and contaminates with a clean soft cloth before the IPA evaporates in order to remove the by products of soldering. I have also discovered that Windex window cleaner can help remove the by-products from the soldering job. Removing contaminates is important as many kinds of rosins are corrosive. Let dry overnight. Position a fan to blow over the board to make sure that all remaining moisture evaporates. While the board is drying, you should carefully check your work for bad solder joints and solder bridges.
Clean PCB of Rosin and By-products of Soldering
Check Board for Solder Bridges and Cold Solder Joints
Chapter 3 Installation, Operation and Help
1. Installation and Operation

Soft Switches

Two soft switches are implemented in the Brain Board hardware. They are used to control addressing of ROMs on the Apple II and PROMs on the brain board. If enabled, the soft switches can accessed from software via the Apple II Device Select signal on the peripheral bus. The location is dependant upon the slot that the Brain Board is located. Depending upon setting of the hard switches, either none or one or the other of the soft switches will cleared or set when the correct location is accessed.

SLOT Clear Set

0 C080 C081

1 C090 C091

2 C0A0 C0A1

3 C0B0 C0B1

4 C0C0 C0C1

5 C0D0 C0D1

6 C0E0 C0E1

7 C0F0 C0F1

When toggling the softswitches, it is best to run the program out of RAM. An example program follows. 1000- AD 90 C0 1003- 6C FC FF LDA C090 JMP (FFFC)

This program clears the softswitch in slot one and jumps to the reset vector at location FFFC in memory. Entering 1000G from the monitor prompt will change the softswitch and jump to the PROMs restart location The first soft switch is called the motherboard soft switch and is used to determine whether the PROM on the Brain Board is addressed or the ROMs on the motherboard when the processor addresses memory in the range of D000-FFFF. If the motherboard hard switch (see hard switch section) is set to disable (switch 3 off and switch 4 on), then the hardware is set to use the Brain Board Proms and the motherboard PROMs cannot be accessed. This setting cannot be overwritten with the soft switch. This is the setting to use if you are trying to operate a motherboard without ROMs. Note that Apple DOS will only boot in this configuration if the PROM in the Brain Board contains images for both Applesoft in one bank and Integer basic in the other or if the init application on the disk being booted uses the same Basic as is installed in the default PROM bank. If the motherboard hard switch is set to enable (switch 3 on and switch 4 off), then either the motherboard ROMs or Brain Board PROMs can be accessed depending upon the motherboard soft switch setting. If enabled, addressing the device select location on the Brain Board will set the Motherboard softswitch to use the BrainBoard PROMs. Addressing the device select location +1 will set the soft switch to use the motherboard ROMs. A program changing this setting should be running out of RAM, not ROM, since the ROM in use will be disabled during execution of this instruction. The default setting after reset is dependant upon the position of the Brain Board toggle switch. If the toggle switch is in the down position, a computer reset will set the softswitch to use the BrainBoard PROMS. If the toggle switch is in the up position, a computer reset will set the softswitch to use the motherboard ROMs.
The other soft switch is the bank select soft switch and is used to determine which bank of the Brain Board PROM is addressed. Standard ROM space on the Apple II is 12K running from address D000 to FFFF. A 27C256 PROM supports 32K bytes of read only memory. When used in the Brain Board, the 27C256 has the capability of supporting 2 complete 12K ROM banks. One application of this capability is to burn the Integer basic, with original monitor and Programmers AID rom in one bank and Applesoft with the autostart monitor in the other bank. That way you can have both Integer Basic and Applesoft in ROM, and dont even need ROMs on the motherboard. This softswitch is used to determine which bank of the Brain Board ROM is selected. If enabled (hard switches 6 and 8 both off), this soft switch is controlled the same way as the motherboard soft switch. This is by either the toggle switch during reset or by accessing the device select address of the Brain Board with software to change the default soft switch setting. When reset to zero, (address C090 for slot 1), the so called low bank is selected (which is PROM address 0 - 3FFF). When set to one, (address C091 for slot 1) the so called high bank is selected (which is PROM address 4000- 7FFF). Note that the highbank and low bank hard switches (see next section) can be used to force the value of the bank select soft switch to a predetermined value that cannot be overwritten by the softswitches or toggle switch.

7&8

Toggle Switch
The position of the toggle switch is sensed during system reset and can be used to select the bank selected by the soft switch after reset in the case when there is more than one possible PROM or ROM bank that could be selected. Moving the switch to the up position selects the low bank during the reset process.
Example Hard Switch Configurations
There are five primary configurations that are most likely to used by Brain Board operators. Single Bank Mode - Low bank of Brain Board always enabled Bank select soft switch and toggle switch settings have no effect. Use this setting with the Wozanium PROM to force Apple 1 operation all the time. Also can be used to force usage of custom PROM low bank all the time.
Single Bank Mode - high bank of Brain Board always enabled Bank select soft switch and toggle switch settings have no effect. Use this setting to force usage of custom programmed PROM high bank all the time.
Dual Bank Mode - Either low bank of Brain Board or Motherboard ROMs selected Toggle switch determines bank in use after system reset. Programs can use the motherboard softswitch (device select) to select either motherboard ROMs or Brain Board low bank. This setting emulates Apple Firmware card operation using the Brain Board low bank. Use this setting with the Wozanium PROM to allow switching between Apple II and Apple 1 mode.
Dual Bank Mode - Either high bank of Brain Board or Motherboard ROMs selected Same as previous setting except the high bank of the Brain Board is utilized. Note that the Wozanium PROMs high bank is left unburned, so this mode should not be used with the Wozanium PROM unless the user programs the high bank of the Wozanium with a program of his choice.
Dual Bank Mode - Either high bank of Brain Board or low bank of Brain Board is selected Toggle switch determines bank in use after system reset. Programs can use the bank select softswitch (device select) to select either Brain Board high bank or Brain Board low bank. One interesting configuration is to program Apple Integer basic with Monitor into one bank of the 27C256 and Applesoft into the other and configure with this setting. When set up this way a ROM-less motherboard may boot DOS and run both Integer and Applesoft BASIC from PROM.

This deposits Al in location 31, A2 in 32, and so on. WP:4
9. Combining examples 7 and 8 in a single command. USER TYPES/ 30: A0 Al A2 A3 A4 A5 (RET) MONITOR TYPES/ 30:FF (prior contents of location 30) 10. Depositing data in successive locations with separate commands. USER TYPES/ MONITOR TYPES/ USER TYPES/ USER TYPES/ 30: A0 Al (RET) 0030: FF :A2 A3 (RET) :A4 A5 (RET)
NOTE: Capital letters enclosed in parenthesis represent single keystrokes. Example: (RET) means hit the return key. Note: A colon in a command means start depositing data from the most recently deposited location, or if none, then from the most recently opened one. 11. Examining a block, then depositing into it. USER TYPES/ 30.35 (RET) MONITOR TYPES/ 0030: A0 Al A2 A3 A4 AS A6 USER TYPES/ :BC El B2 E3 B4 E5 (RET) Note: New data deposited beginning at most recently opened location (30) 12. Run a program at a specified address. USER TYPES/ 10F0R (RET) MONITOR TYPES/ 10F0: A9 (contents) Note: The cursor is left immediately to the right of the A9, it is not returned to the next line. 13. Run at the most recently examined location. USER TYPES/ 10F0 (RET) MONITOR TYPES/ 10F0: A9 USER TYPES/ R(RET) 14. Enter a program into memory and run it in one line. USER TYPES/ 40: A20 EF FF 0 4C R (RET) MONITOR TYPES/ 40: FF (prior contents of 40)
15. An on line error correction. USER TYPES/ 40: Al A2 A3A4A5A6 A7 (data A6 will be loaded in location 42) USER TYPES/ 40506070: AA (data AA will be loaded in location 6070) 16. Useful routines in monitor which can be accessed by user programs. GETLINE: location FF1F monitor entry point (jumping to FE1F will enter monitor and echo carriage return. You can then examine memory locations with the monitor.) ECHO: location FFEF prints one byte (ASCII) (data from A (accumulator), contents of A not disturbed.) Example: 20 EF FF (JSR ECHO) PRBYTE: location FFDC: prints one byte (HEX) (data from A, contents of A disturbed.) PRHEX: location FFE5: prints one hex digit (data from four least significant bits of A, contents of A disturbed.) NOTE: RAM locations 0024 to OO2E are used as index pointers by the monitor, and are invalid for user use, when using monitor. Also, locations O200 to 027f are used as input buffer storage, and are also invalid for user use when using the monitor.
Chapter 2 - Wozanium Pack - Apple Cassette Interface Guide
This chapter contains edited content from the original Apple-1 Cassette Interface manual. All commands are unchanged from the original Apple 1 manual. The only edits are to remove or edit content that is not applicable to the Apple II/Brain Board environment. The Wozanium Cassette Interface [WCI] is a driver that emulates operation of the original Apple 1 Apple Cassette Interface (ACI) using Apple II hardware. This enables the user to store and retrieve information (data and programs) using a standard audio grade cassette recorder or an iPod. The operator can save and restore programs and data exactly as with the original Apple 1. The data format is identical, so data can be exchanged between original Apple 1s and an Apple II equiped with the Wozanium drivers. The WCI uses Apple II cassette interface hardware, so the cassette interface connection is the same as with an Apple II. The WCI reads and writes data at the rate of approximately 1500 baud (depending upon the data), Like the original, all the WCI timing is done in software, resulting in extreme accuracy, no adjustments, and consistency between cassette recorders. With the original Apple 1 ACI card, performance with various cassette recorders can vary from not functional to works pretty well. The Apple II has an improved cassette interface circuit over the orignal Apple 1, so in general performance should be satisfactory, once a good play back volume is settled upon. I use and recommend a Panasonic RQ-2102, which is a direct descendant of the original Apple recommended cassette recorder. The WCI program is contained in the low bank of the Wozanium PROM included with the Brain Board and runs at either D000 or if the Brain Board is installed in slot 1, C100. The original ACI software would be involked at location C100, so for the most authentic, operation install your Brain Board in slot 1. When C100R is entered, the program should echo an *. The format for specifying the memory address ranges to be either stored (write) or deposited into (read) is identical to the standard monitor format: Beginning. End , suffixed with either a W (write) or an R (read). Execution will start following a carriage return (CR). The cassette program will return control to the system monitor upon completion of a read or write. Illegal characters (or the absence of characters) in the address line will return control to the system monitor without execution, following a carriage return.

What I/O capabilities did an original Apple 1 have?
The Apple 1 video section has only two functions. Clear screen and set cursor to first location at top left hand corner. The clear screen function is a hardware function activated by directly connecting the clear input on the keyboard socket to +5volts for one screen refresh time period (60 milliseconds). This will clear all of screen memory and set the cursor to the top left hand corner. Note that upon power up, and Apple 1 screen will be filled with garbage including numerous cursors, which makes data input nearly impossible until the screen is cleared. Write a character to current cursor location and advance the cursor to the next location. If the cursor is on the last location on a line, the cursor is moved to the next line and that line cleared. If the cursor is at the bottom of the screen, the entire screen is scrolled up one line. If a carriage return is entered, the rest of the current line is cleared and the cursor advanced to the first position on the next line on the screen and that line is cleared of any old characters. If the cursor is at the bottom of the screen, the entire screen is scrolled up one line.

The Video Port

The Apple 1 assembly code for performing a write character to the display is shown here WAIT:BIT DSP $D012 ; TEST MSB OF PIA REGISTER TO SEE IF TERMINAL IS READY BPL WAIT ; NOT SET, THEN WAIT STA DSP $D012 ; STORE CHARACTER IN PIA TO WRITE TO SCREEN WP:10
Because the display memory is a large circular buffer that is constantly shifting, the write must wait until the moment that the position of the cursor is available to the PIA before a character can be written to the screen. This results in a display speed of about 60 characters per second, though entering carraige returns will appear to run faster because the hardware does the clear to end of line function automatically at a relatively fast speed. There is an ECHO function located at location FFEF in the Apple 1 montior that can be called instead of writing the code to write to the PIA directly. Many Apple 1 programs use the monitor ECHO call instead of accessing the PIA directly. In contrast, the Apple II uses a memory mapped video system where writing to memory causes data to be displayed imediately on the video screen. There is no need for software waits or delays in using this video system. Several memory banks are allocated to video display and can be switched using software controlled soft switches. 0400 - default text and low res graphics 0800 - secondary text and low res graphics 2000 - primary hi res graphics 4000 - secondary hi res graphics The Apple 1 has a memory bank starting a location 0 and running to either FFF (4K systems) or 3FFF (16K systems). Except for the stack at the page starting at location 200, Apple 1 programs assume that these locations are available for use. In order to run 16K Apple 1 programs on an Apple II, video display has to utilize the secondary hi res graphics space starting at address 4000. A video driver has been written that is called to display textual data in the secondary hi res graphics space. Behavior, performance and capabilities of this driver mimic behavoir of the Apple 1 terminal driver as closely as possible. The Apple 1 monitor ported to the Wozanium, is modified to use this video driver instead of the PIA of the Apple 1. Thus any Apple 1 software that utilizes the monitors ECHO routine will automatically work in the Wozanium environment. Apple 1 software that directly accesses the PIA needs to be handled differently. How this is done, is covered under the cassette interface section of this chapter. There are a couple subtle differences between this video emulation of the Apple 1 and the real thing. Since it is handled in software, rather than hardware, the cursor only flashes in this environment when the program is waiting for keyboard input Because the rest of the current line and the next line must be cleared in software, Carriage Return performance is somewhat less than on a real Apple 1, where the same function is handled in hardware The Wozanium video output routine provides a capability for a user driver to replace or supplement the Wozanium video output (putchar) routine. Typical usage would might be a Super Serial card driver that could be used to dump Apple 1 programs to a terminal or PC for archiving purposes. The user places the function address in the locations BC04 (LSB) and BC05 (MSB). The user has the option of returning directly from his replacement driver by executing RTS from his driver or to the Wozanium video output driver by jumping directly to the address that was in address BC04 and BC05 prior to the new driver being installed. For rev 5.1 PROM, this is initially D44A. All registers should be restored before returning or jumping to the Wozanium driver. The user driver can be loaded in and use the address range of 6000 to BBFF. The user driver should refrain from disturbing memory outside of this range. Loading this driver would typically be done through the cassette interface. The user vectors will be overwritten by default Wozanium vectors whenever the computer is reset.

Keyboard input on the original Apple 1 utilized 2 registers in the PIA located at D000. D011 - keyboard control register - high bit (bit 7) when set indicates that there is data from the keyboard ready to be read. Reading this register clears the flag D010 - keyboard data The code sequence listed below is the normal routines used to read the keyboard. WAIT:LDA $D11 ; TEST CONTROL REGISTER TO SEE IF KEYBOARD DATA ; IS PRESENT (THIS READ ALSO CLEARS BIT) BPL WAIT ; BRANCH TO WAIT, IF MSB NOT SET (NO DATA PRESENT) LDA $D010 ; READ KEYBOARD DATA The Apple 1 monitor does not have a routine for getting a single character from the keyboard. Keyboard input on the Apple 2 is slightly different, but also utilizes 2 memory locations C000 - keyboard data, the most significant bit (bit 7) is set if new keyboard data is present C010 - keyboard control register - the high bit (bit 7 - new data available indicator) of keyboard data is reset when this location is accessed Read Key from keyboard on Apple II: WAIT:LDA $C000 BPL WAIT STA $C010 ; READ DATA REGISTER TO SEE IF KEYBOARD DATA ; IS PRESENT (MSB SET IF NEW DATA PRESENT) ; BRANCH TO WAIT, IF MSB NOT SET (NO DATA PRESENT) ; CLEAR KEYBOARD DATA PRESENT BIT

Keyboard Input

Fortunately both Apple 1 and Apple 2 read keyboard sequences are 8 bytes long, so one can be substituted for the other. This has been done for you in the modified Apple 1 monitor provided with the Wozanium. Read the cassette interface section to find out how the Wozanium accomplishes this in downloaded Apple 1 programs. The Wozanium keyboard routine provides a capability for a user driver to replace or supplement the Wozanium keyboard read (getchar) routine. Typical usage would might be a Super Serial card driver that could be used to allow remote control of the computer. The user places the function address in the locations BC02 (LSB) and BC03 (MSB). The user has the option of returning directly from his replacement driver by executing RTS from his driver or to the Wozanium keyboard input driver by jumping directly to the address that was in address BC02 and BC03 prior to the new driver being installed. For rev 5.1 PROM, this is initially address D250. Note that if the Wozanium keyboard input driver does not detect that a character is ready from the keyboard, it will repeat the call to the user driver until a character is available from the keyboard to return to the calling function. This allows usage of both user input and keyboard input concurrently. All registers should be restored before returning or jumping to the Wozanium driver. The user driver can be loaded in and use the address range of 6000 to BBFF. The user driver should refrain from disturbing memory outside of this range. Loading this driver would typically be done through the cassette interface. The user vectors will be overwritten by default Wozanium vectors whenever the computer is reset.

The original Apple 1 uses a plug in card known as the ACI (Apple Cassette Interface) to read and write cassette tapes. On this card, there is a 256 byte program in PROM, located at address C100 that contains the driver for this interface. Like the original Apple 1, cassette read functions on the Wozaniam Pack are also accessed by running the ACI driver, which if the Brain Board is located in slot 1, is also at address C100. When the Apple 1 is reading data off the tape, hardware tracks incoming signal and toggles a flip flop whenever the state of the incoming signal makes a transistion from high to low or low to high. The output of the flip flop is used as the least significant address bit when reading the cassette interface PROM from address C000. Since PROM locations 0 and 1 have different contents, the cassette read driver can easily tell when a transistion has occurred on the tape, since the data returned by a read from location C000 will change with every transition. The Cassette driver simply measures the length of time between each transistion to determine whether a zero or one is being read. The Apple II uses similar hardware to track the input signal from the cassette player. One difference is that the flip flop is located at C060 in memory and can be directly read by the driver. One other difference is that the cassette interface circuitry that feeds the flip flop was improved somewhat for the Apple II, so reading tapes becomes a slightly more reliable affair than it was on the original Apple 1. Note that the data format on the Apple 1 and Apple II remained the same, except for a CRC was added to the end of the recording on the Apple II. The Wozanium Pack uses a modified version of the Apple 1 ACI cassette driver to read Apple 1 tapes on Apple II hardware. The following changes were made in this driver. Instead of monitoring address C000, C060 is moitored for transistions in the incoming cassette read signal After each block of data is read, the driver will scan input data looking for accesses to either the keyboard or video PIA ports and convert those accesses to work with the Wozanium PROM and Apple II hardware Since an Apple II is about 5% faster than an Apple 1, software timing loops were slightly tweaked to reflect the increased speed of the Apple II

Cassette Tape Read Functions
Like the original Apple 1, cassette write functions on the Wozaniam Pack are also accessed by running the ACI driver, which if the Brain Board is in slot 1, is also at address C100. Both the Apple1 and Apple II use virtually the same technique to write data to the cassette tape interface. A hardware flip-flop is toggled by the cassette interface driver at a specific frequency to represent a zero or a one on the tape. The primary difference is the flip flop is located at different addresses on the two systems. The Wozanium Pack uses a modified version of the Apple 1 ACI cassette driver to write Apple 1 tapes on Apple II hardware. The following changes were made in this driver. Before each block of data is written, the driver will scan output data looking for accesses to either the Apple II keyboard or Wozanium video driver and convert those accesses to work with original Apple 1 hardware Instead of writing to address C000, C020 is writen to cause transistions in the output cassette write signal After each block of data is written, the driver will scan ouput data looking for accesses to either the keyboard or video PIA ports and convert those accesses back to work with the Wozanium PROM and Apple II hardware Since an Apple II is about 5% faster than an Apple 1, software timing loops were slightly tweaked to reflect the increased speed of the Apple II
Cassette Tape Write Functions
There were several versions of Apple 1 basic released during the lifetime of the Apple 1. The version included with the Wozanium pack is the last known version, known as the Huston version. There are two differences between Apple 1 Basic in the Wozanium and running Apple 1 Basic on a real Apple 1. Apple 1 Basic is preloaded into PROM at address E000 on the Wozanium. In an actual Apple 1 you would have to load Basic into DRAM at address E000 from tape using the cassette interface The version of Apple 1 Basic on the Wozanium has been modified slightly to use Apple II hardware for keyboard input and the Wozanium video driver for output.
To return to Apple 1 Monitor without resetting the computer, you can do one of the following. To return to the Monitor without resetting user getchar and putchar vectors: type CALL -225 from the BASIC prompt. To return to Monitor and reset user getchar and putchar vectors: type CALL -256 from the BASIC prompt.

C100 Run ACI driver if Brain Board is in slot 1 D000 If Brain Board is another slot 6000-BBFF Space for user driver functions
Useful Wozanium Pack Addresses
D24D Get character (getchar) from keyboard - Wozanium function BC02-BC03 Vector for user getchar routine Return from user getchar routine bypasses Wozanium getchar routine JMP D250 afterwards to continue with Wozanium getchar routine BC00 Turbo mode Set to 1 increase text output speed. Default setting of zero closely mirrors original Apple 1 display performance FFEF Put character to screen (putchar) - call standard monitor echo routine BC04-BC05 Vector for user putchar routine Return from user putchar routine bypasses Wozanium putchar routine JMP D44A afterwards to continue with Wozanium putchar routine BC01 Cassette input/output conversions. Controls conversions from original Apple 1 to Wozanium format and visa versa. This setting should be only used by experts who understand what they are doing. Set to 1 to stop conversion of cassette read and cassette write data Default setting of 0 enbles conversion of cassette read and cassette write data D1CE Convert block of Wozanium code to original Apple 1 format (used by cassette write function). Before calling, fill in start and end address. BC11 (low) - BC12 (high) start address 24(low) - 25 (high) end address (also used by monitor) D11B Convert block of original Apple 1 code to Wozanium format (used by cassette read and write functions). Before calling, fill in start and end address. BC11 (low) - BC12 (high) start address 24(low) - 25 (high) end address (also used by monitor) DFFE-DFFF Wozanium PROM version - this document describes version 5.1
Feel free to send email to: mike@willegal.net if you run into difficulties.
Chapter 5 - Wozanium Pack - Quick Start Guide
Follow directions detailed in Chapters 1 and 2. Dual Bank Mode - Either low bank of Brain Board or Motherboard ROMs selected
Build Your Brain Board Set slide switches
Set toggle switch in up position: Enabling Brain Board low bank With power turned off, insert Brain Board into slot 1 of your Apple II with components side ofthe Brain Board facing away from power supply. Turn power on. If will take a few seconds for the Wozanium to initialize itself and display the Apple 1 start up screen. The start up screen is alternating flashing @ signs and underscore characters. You should then clear the screen by pressing the right arrow key. At the prompt, type- 0:AAA 20 EF FF E8 8A 4C 2 0(RET) 0 is a zero, NOT an alpha O; and (RET) hit the return key on the keyboard. Type 0R (RET) to run the program. The program should then print out on the display a continuous stream of ascii characters. To stop the program and return to the system monitor, hit the reset button. To run again, type - 0R (RET). Unlike the original Apple 1, in the Wozanium environment, BASIC is preloaded into PROM. From the monitor prompt type E000R to enter BASIC and erase any existing program. To re-enter BASIC without destroying an existing BASIC program type E2B3R.