Which PERQ do you have? The PERQ 1 keyboard is an 8 bit parallel interface with a strobe signal. The coding is basically ASCII, but the cotnrol key sets the MSB (and leaves the other bits unchanged). I can get the exact details. The DDS (diagnostic display) is a simple up-counter, cleared by the reset button and incremented by a signal from the PERQ (it's actually the same signal that clears the arithmetic stack pointer, not that you need to know that). The PERQ 2 keyboard is serial, TTL level, and 300 baud. IIRC, the character codes are the same as on a PERQ 1. It plugs into the monitor, but there's no eleectronics for the keyboard (or tablet) in the monitor, just conenctions between DIN sockets and the DA15 to the PERQ. It's possible to use a computer with an RS232 port to emulate a PERQ2 keyboard, all you need is a 1489 chip as a level shifter (which can be powered off the PERQ's keyboard port). The monitor is TTL levels, separate syncs (so a total of 3 signals). Scan rates are something like 64kHz horizotal, 60Hz vertical. Whether you need a poertait or landscape monitor depends on the memory board you have (!), it's possible to convert some between one and the other (in particular, going form a landscape board to a portrait one), but it's probalby not soemthing you want to try before you've got the machine working. In general, PERQ 1/1a machines used a VMI portrait monitor, 2T1s used a KME portrait monitor, 2T2s and 2T4s normally used a Moniterm landscape monitor, but there's rumoured to be a PERQ Systems portait monitor for those too. Be warned that the Moniterm landscape monitor used on the PERQ 2T2 and 2T4 is known for developing problems iwth the partially potted EHT PSU module, resulting in a dim or no image. So if you find one, it may not work... If you want to try adapting something else, let me know, and I'll dig out any useful details. -tony