Sinclair ZX80 / ZX81 / Z88 Forums

Hi everybody !
I found my old GP50s in some old school things but an essential part is missing .... the GP0520 connector for the ZX81

Does anyone have one to look the printed circuit diagram inside, there is just two screws to open it so i can try to build a new one ?

Thanks et good day to you !

Hi Dim,

If the Seikosha 50 (not a Centronics hardware) is a TS2040 compatible hardware, i have this connector:
https://www.sinclairzxworld.com/viewtop ... 243#p49243

The difference can be seen on the busses from the ZX81 and the ZX Spectrum.

It will only be the higher addresslines. So you can easily built a pseudo ZX Spectrum bus where
you will connect the higher addresslines to GND to make it work.

HI,

It seem to be a ZX81 BUS to ZX SPECTRUM connector... Too big to enter in the ZX81 ! (Thanks Johan !)


Have a look to my PCB : https://www.sinclairzxworld.com/viewtop ... 746#p56746

Have fun.

XavSnap wrote: ↑Tue Sep 24, 2024 5:53 am HI,

It seem to be a ZX81 BUS to ZX SPECTRUM connector... Too big to enter in the ZX81 ! (Thanks Johan !)

Back_Ext_Diagram.pdf



Have a look to my PCB : https://www.sinclairzxworld.com/viewtop ... 746#p56746

Have fun.

I once built a SAM Coupe to ZX Spectrum connector so we could try interfaces from the ZX Spectrum on the SAM Coupe.

Hi Dim_75,

I have a spare one for you!

Hi !!! One at last ! You have one left you could sell ???

Yep, one on the right is for sale.

Man, they say the ZX80 is rare. I see lots of them weekly on ebay. But this thing, now that's really rare!

I find it humorous that the edge-connector has a Texas Instruments logo next to the words "made in japan"

note: this is not the adapting connector, but only the sub-component
edge-connector: Texas Instruments H421121-25 348


I remember Seikosha used to be a famous printer company back in the 1980s. Seikosha Graphic Printer GP-50S was for use with ZX Spectrum or ZX81 (or Timex/Sinclair TS15000 as your photo shows). That connector makes me think that it may have been an RS232 printer rather than the more common parallel type from the late 1980s

A Chroma Interface without case can also be used for connecting a GP-50S to the ZX81.