RETRO Innovations

PS/2 Encoder interfaces industry standard PS/2 PC-compatible keyboards to devices requiring TTL-level RS232 or parallel data signaling.  All ASCII key sequences are decoded, as well as common keyboard sequences like "CTRL-ALT-DEL".  To provide maximum flexibility for various uses while retaining ease of operation, the unit's configuration can be modified in-circuit using the PS/2 keyboard itself.  Features include:

• Unit outputs ASCII via 8-bit parallel port and RS232
• Parallel output support configurable active high or active low strobe
• Output supports variable intercharacter delay (0-2.5s in 10mS increments)
• RS232 bps rate can be set from 110-57600 bps
• BS sends either BS or DEL
• CR sends CR or CRLF
• Crystal is optional
• CAPSLock operation works
• Indicator LEDs are supported
• Configuration can be performed from the keyboard.  When CONFIG jumper is installed, Ctrl/Alt/BS places the unit into configuration mode, where keypresses set various options.
• Special "raw mode" sends actual PS/2 keyscan values to the RS232 and parallel ports.

Technical Details

PS/2 Encoder consists of an Atmel ATMEGA88 AVR microcontroller and associated connectors.  The unit can be ordered as a base PCB, a minimal parts kit, a full parts kit, or a completed unit.

The PCB features include:

• Supports 24 pin .6″ IC socket connection as well as 2×12 header connection.
• Crystal footprint included on PCB
• PS/2 connector footprint included on PCB
• Through hole design makes "do-it-yourself" construction easy.

Construction details and configuration settings are available on the product information page.