On 9/10/23 09:44, Liam Proven via cctalk wrote: > No idea of the CPU performance. 4MHz Z80A but whether there was any > contention or anything I have no idea. I believe one of the > interesting bits of the design is that there's no ROM at all. They > came with a dedicated printer (as well as a Centronics port) and > masked into a corner of the printer controller chip was a tiny bit of > bootstrap code.
>From my PCW tinkerings--I bought it for the CF drive, so it was mostly a curiosity with me. I think the base unit (120VAC) was sold by Sears in the US for a time. I grabbed one locally and upgraded the RAM to 512K and a 3.5" 720K drive (Teac FD235F)--the READY line is required for operation. I noted that changing a single byte in the boot code enabled support for DS media. But the "no ROM" claim should probably be modified to "no discrete ROM", as I believe the boot code is contained in the printer controller and is strobed onto the Z80 bus at IPL time. Almost certainly mask-programmed. The PCW, although interesting languished in my shop for about a decade. Finally was contacted by someone who was willing to drive up from California and relieve me of it. He also received an AT&T 6300 for his troubles. I am loath to recycle old interesting gear, but am willing to give it away to interested parties. --Chuck --Chuck
