TRS-80 curiosity

On Wed, Apr 12, 2017 at 8:15 PM, Fred Cisin via cctalk <cctalk at classiccmp.org> wrote: There was a 'cable' (containing a few TTL ICs) to link a Centronics printer to a Model 1 CPU/keyboard unit without needing an expansion interface. It was in 2 parts. The short one included the logic and had a 40 pin edge connector on a short length of ribbon cable connected to the box containing the logic. The PCB in said box had a _40 way_ card edge coming out through the side with a slot after 34 contacts. There was a longer cable with a 40 way edge connector (with a polarising key after 34 contacts, between the contacts) on one end and a 36 pin microribbon connector (to go to the printer) on the other. You connected the long cable to the card edge on the box of logic, plugged the short cable from that into the expansion bus connector on the keyboard and plugged the other end of the long cable into the printer (which had to supply the +5V needed for the logic in the cable). If you then bought an EI, you could connect the long cable (only) to the 34 pin card edge on the EI. The only problem was that if you did this, you couldn''t fit the 'hood' over the connector (as it was designed for a 34 pin connector). And the cable didn't fit the M3 or M4. I had one. In the end (after getting an EI and later a M3), I replaced the connector with a 34 pin one. It then didn't fit the original short cable/logic (which I had no use for), but did work with the EI and M3. -tony