Discussion forums for users of the Sinclair 8-bit range of computers - ZX80, ZX81, ZX Spectrum, Z88, clones...
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Erm wrote: ↑Sun Sep 20, 2020 9:53 pm Hello.
For sale here is a Memotek I/F Centronics Type Parallel Printer Interface plus what looks to be a home/kit made Centronics Interface of some kind.
The Memotek device: is in excellent condition, gorgeous satin black metal with hardly a mark on it. The PCB inside also looks great. I don't have the cable that goes with it, nor do I have a Centronics printer so to test it I plugged it in to a bog standard ZX81 and it booted as normal. I was then able to Peek the addresses of the Memotek ROM (2800h to 2A00h) and those addresses certainly read differently compared to when the interface is not attached (e.g.10240 is 32 with it plugged in and 24 without it). So it's certainly 'there'.
The other device: appears to be home-made, but perhaps from some kind of kit as the PCB has 'Centronics' written on it and was certainly designed for a ZX81. The ZX81 expansion plug appears to have been sourced from a ZX Printer. It has 3x 74X chips on on the other end is a Centronics type connector. The ribbon to this connector has 3 wires that were either never connected or have become unattached - I think I can make out where 2 of them were once soldered and the 3rd is a mystery.
£70 plus postage (for both devices).
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