A tari - K eyboard - I nterface

Connect a PC-Keyboard to your ATARI 800/130!
  • all common PC Keyboards (MF2 Standard) useable
  • 99% ATARI-compatible
  • several keyboard layouts (languages)
  • simply to install, no tuning
  • ATARI keyboard can be used the same time
  • macro memory for up to 60 keystrokes, will be hold after power off
  • AKI software can be updated
New professional manufactured board now available !
  • No more soldering on the POKEY (only if POKEY is socketed)
  • passive components in SMD package
  • no small SMDs, so it can be soldered by hand
  • it can be placed inside the shield
  • most connections are plugable, only 5 soldering points
  • socket for optinally macro EEPROM (up to 8KByte)
Sorry for my bad english, if theres somebody who can help me with a better translation contact me !!! MacFalkner@aol.com

1. some short infos

AKI is a small interface platine to connect the ATARI 800/130 with every common PC-AT-keyboard (also Windows 95 keyboards). The old ATARI keyboard will be useable the same time. The AKI interface and the 5c DIN connector / or PS2 connector are build inside the ATARI. Its simple to build in cause there is only a small soldering work to do. The interface is placed 'up-packed' to the ATARI keyboard chip (POKEY), therefore the connection is very solid. AKI is 99% softwarecompatible cause it is simply parallel switched to the old keyboard. The POKEY chip will not be able to detect differences in the signals. The compact layout allows to put the interface direct up to the POKEY (ca. 25x50mm). The AKI CPU can be updated with new firmware*

* The PIC must be placed into an PIC programmer device, also programming software will be required.
AKI component side (new layout) AKI soldering side (new layout)

One of the first tries of the AKI hardware :-) handmande board of the new layout with POKEY, EEPROM and PIC. Some SMDs are on the soldering layer

2. Build in

First, before you start, you will need an PC-keyboard. They are very cheep this time, its no problem. Who wants to use an ergonomic cherry keyboard can do this also :-). Look for 101/102 keys and MF2 standard. 5p DIN and PS2 can be connected. All keyboards common this time, do this !!! Newbies better use the DIN connector cause the PS2 is more difficully to sold.

All work should be done when the ATARI is switched off. Also a basic electronic tool set should be availaible (theres no need of an oscilloscope etc.).


Now follow the steps:

Open the ATARI, put a hole for the connector. The connectors should be placed from outside, then you will have no problems with the fixing holes. A solid mechanical connection will be recommended. There isnt an exact position giving for the connector. Everybody can choose its own place. You should use short cable connections to the AKI. Lengths under 50cm are uncritical. Attention! A longer shortcut of the power supply can be bad for the ATARI-supply unit, a longer swap of the power supply lines will be bad for the AKI CPU (PIC) and can kill the PC keyboard. A swapping of the datalines will have no destroying effect (normally :-)).
The figure shows the insertation of an 5p DIN connector in the ATARI 800XL. Its placed between the SIO connector and the bus expansion port.
The AKI interface is placed 'up packed' to the POKEY chip (10 soldering positions).It will be nice to have an ATARI with sockets for the chips !!! Place out the POKEY, sold on the AKI and place the POKEY back. If your POKEY have no carrier are there 3 variants: The first one, you sold the AKI direkt onto the PIC, this is something complicated cause theres not much space to sold. The second is you place a socket for the POKEY, but this is much work and should only be done from professionals. The third version is you sold an 40p carrier up to the PIC an plug the AKI inside. In this case you must put a hole in the ground shield (the ATARI can also work without the shield, but there can be reduced video picture quality). Eventually, an capacitor, right under the POKEY must be layed down.

Insertation of the first prototype in the ATARI 800XL.

Connecton of START, SELECT and OPTION in an ATARI 800 XL (the 3 resistors are right down outside the ground shield).

Connecting RESET line (gn / wh), right under the AKI.
Signal definition ATARI 800XL / 130XE
START  left side from R134 
SELECT  left side from R135
OPTION  left side from R136
RESET  left side from L14

Now, also a connection to a switchable RAM-Disc can be done. This can not be specified without knowing of the inserted RAM-Disc technology, see section "AKI and RAM Extensions" for more details.

Now turn on your ATARI, test the function of the old ATARI keyboard. If it works, plug in the PC keyboard and start ... You can start the ATARI build in keyboard test, but this will not be a good indicator to test the PC keyboard. If only one key dont work, the defect is placed in the PC keyboard. If nothing works the whole installation must be checked. Latest, after plug out the PIC of the AKI, the old ATARI keyboard must work.

Some tips for troubleshooting:

3. Keyboardlayout

fig. 8: PC-MF2-standardkeyboard (english Version, keys 42 and 45 added on german layout)

The PC-keyboardlayout is mostly identic with the printed symbols on the keys with the german / english (american) keyboard. The english layout is mostly common with the original ATARI layout, maybe some german PC users prefer her layout.

Keynumbers with several language functions: 3,7,8,9,10,11,12,13,22,27,28,40,41,42,45,46,53,54,55.

Here are the special funtioin keys:
PC key ATARI-Emulation
F1  ATARI (1200er) F1 key* , also SHIFT / CTRL
F2 ATARI (1200er) F2 key* , also SHIFT / CTRL
F3 ATARI (1200er) F3 key* , also SHIFT / CTRL
F4 ATARI (1200er) F4 key* , also SHIFT / CTRL
F9 free
ALT-F9 sending macro 1
ALT-F10 sending macro 2
ALT-F11 sending macro 3
ALT-F12 sending macro 4
CTRL-ALT-F9 recording macro 1 (max. 15 keystrokes)
CTRL-ALT-F10 recording macro 2 (max. 15 keystrokes)
CTRL-ALT-F11 recording macro 3 (max. 15 keystrokes)
CTRL-ALT-F12 recording macro 4 (max. 15 keystrokes)
ALT-F1 sending AKI versionnumber 
ALT-F2 sending fixed macro ‘POKE’ (for a faster keyboard in BASIC)
ALT-F3 switching between german and english keyboard layout (stays after power off)
ALT-F4 stop macro recording 

* there are some ATARI models wich have keys F1...F4. These keys are supported from the ATARI OS (also 800/130er OS!) and have following functions:
F1 Cursor up
F2 Cursor down
F3 Cursor left
F4 Cursor right
SHIFT-F1 goto top of screen (HOME)
SHIFT-F2 goto end of line
SHIFT-F3 goto start of line
SHIFT-F4 goto bottom of screen
CTRL-F1 switchs off keyboard until pressing CTRL-F1 (Attention trap!!!)
CTRL-F2 switchs off screen until pressing any key
CTRL-F3 toggles keyboardclick
CTRL-F4 toggles charset (graphic / international)

4. Softwarecompatibility

Like said above, AKI is 99% softwarecompatible, cause the ATARI is not able to detect differences to the original keyboard. Here are some differences (the 1 percent):

* If it comes to a ghosting effect (the keyboard controller detects keys that are not stroked) through pressing more than two keys at the same time, the keys they are first scanned (in matrix order!) are guilty. This can be readed in the technical documents for the keyboards. Another interesting effect is occuring when two keys are pressed very quick. The ATARI-OS is not able to detect 2 several keys in 100ms. Now with an new keyboard you can press the keys quicker, therefore it can be that some strokes are ignored. (for instance LDA > LA or STA > SA). Now AKI software caches 2 keystrokes, so this effect will be reduced.

5. AKI and RAM-Expansions

There is an output on the AKI interface, especially designed to switch RAM-Disc systems with a bank switching option. The 2 ATARI switching is very easy with the AKI. Press RESET for the first one, SH-RESET for the second. The output is switched some time after activating the RESET signal, so a sure switching is guaranteed. There are many several extensions for the ATARI available, so i cant give an exact description, how to do. Mostly the OS / RAM selection is done by an mechanical switch. The following methods are common:

The AKI ouput has an so called 'open collector' therefore not all variants are uncritical to connect. Variant "A" gives no problem, the AKI switching output can be directly connected to the input of the extension (take care that the resistor dimension is >1KOhm). Dont connect to variant B or C, destroying the PIC can be result. If you have variant B or C in your ATARI, rewire it to variant A, the switching ability stays the same. Now you can contact your AKI output additianally.

6. Technical infos

The AKI is a one chip processor system with an PIC processor with 64 byte internal EEPROM. The hardware is mostly the standard application for the PIC processor. The PIC is receiving the serial AT keyboard codes, interpreting it and simulate an keystroke in the ATARI keyboard matrix. The SHIFT and CONTROL keys are 1:1 software connected. The supply current is typical 20mA and the PC keyboard needs 70mA-160mA, and its no problem for the ATARI power supply.

Schematic (GIF, 30KByte, 300dpi)

Layout (GIF, 12KByte, 300dpi),  new SMD Layout (GIF, 20KByte, 300dpi)

Hexfile for PIC-Programming, actual Version! (Intellec8, 6KByte)

The following components are needed:

Some infos for the insider (sorry, only in german this time):

Funktionsweise von AKI, Matrixcodes (Scancodes) der ATARI-Tastatur ... u.v.m ! (TXT, 7KByte)

Liste mit allen bisher durchgeführten Änderungen (Bugreport) !

7. Selling, Handling, Quality and further development

This is a hobby project of mine, that is free availaible for all ATARI freaks. This document and all linked files are ‘F r e e w a r e’ and can be copied free or for a selfcost price. The copying of CAD and assembler sourcefiles is   n o t   a l l o w e d . Reproducing the hardware is free for single boards for private/friends. The reproducing for commercial is    n o t   a l l o w e d .

Please contact me for availability / delivery outside germany MacFalkner@aol.com
AKI complete and tested, incl. all wires and plugs 30,- Euro/US$*
AKI PIC programmed with the newest software version   15,- Euro/US$*
AKI board (empty), double sided, solderstopmask 15,- Euro/US$*

* all prices without P+S.

I will be enjoyed for tips to upgrade the PIC software or reported bugs, or contact me if you have some questions: MacFalkner@aol.com


Many thanks to: 11.10.1998 / 05/1999, André Bertram.  MacFalkner@aol.com