ASCII to PS/2 Keyboard Adapter

This board converts either a PS/2 keyboard input or RS232 input into a ASCII keyboard interface. It has been tested with the Apple 1 and Apple II models, but other vintage computers that take a parallel ASCII keyboard interface should work. Apple IIe and later Apple computers will not work with this interface. See my blog or video podcast for more information.

Version 3.0 Firmware Changes

In order to allow support of different styles of ASCII parallel keyboard interfaces, options for additional styles of strobe handling has been added. In addition to disabling control-RST and control-CLR functionality, inserting the CR jumper also causes the SRB output pulse to be maintained until CLR, which becomes an input, is asserted (high). When the CR jumper is inserted, connecting SRB output directly to CLR input, will result in the normal 125 micro-second pulse. If you connect the SRB output directly to CLR input with an appropriate resistor (say 10K) and connect the CLR input to ground with an appropriate value capacitor (say .1uF), you create a RC timing circuit which can be used to extend SRB. The aforementioned values will extend strobe to 1 millisecond, but other values can be used to set the timing to a value that you desire. With the CR jumper inserted, the CLR TTL input can also be connected to external logic which can terminate SRB in any arbitrary fashion.

Pricing

Read the Manual before ordering (currently version is 3.0).
You must supply keyboard and/or cable for computer's RS232 interface.

Price for a keyboard adapter kit is $35, postage is $5 within USA, $10 elsewhere
I can assemble kits for an additional charge of $25. (specify either Apple 1 or Apple II - I can not build kits for other types of computers because I cannot test them)

Send mike@willegal.net an email for payment information.

Features:

Use a regular PS/2 keyboard on Apple II or other vintage computer that accepts ASCII keyboard input
Upper and lower case support
Support PS/2 numeric keypad (numeric mode only - cursor controls will not work)
Use PC terminal program (hyperterm) running on modern PC, for vintage computer input device
Echos PS/2 keyboard input to RS232 TX for input logging purposes
cntrl-R - cntrl-S - cntrl-T reset sequence pre-programmed
You can use terminal programs on a PC to send scripts of commands to target computer keyboard input interface. This is an easy way to load programs into vintage computers that otherwise must rely upon unreliable media, such as a cassette interface.
Can be adapted to other vintage micro-computers by rewiring connection to target PC
Operates from +5 volt supply (amperage requirements to be determined shortly)
RS232 runs at 9600 baud
Shift lock support - sending commands to change the LED status on the keyboard is trickier than one might imagine, but I finally have it working
Arrow mapping to Apple esc-char cursor movement (Apple II specific)
Cntl-Alt-Del reset support
Easily jumperable keyboard 16 pin socket pinout - will allow apple 1 and other vintage computers with DIP16 header connections to use straight through ribbon cable connection
Clear screen strobe support using cntrl-C cntrl-L contrl-R sequence (intended for apple 1)
Optional automatic reset and clear screen after power up (version 2.2 and forward)
Support for stretching strobe and holding strobe until acknowlegement (version 3.0 and forward)

This Project was Inspired by Other Peoples Work

First Prototype Adapter Hooked Up to an Apple II on One End - a PS/2 Keyboard and a PC via RS232 on the Other

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