Wanted : a ZX81 I/O board extension

ZX80 / ZX81 hardware and software requested for either sale or swapping
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YannFr
Posts: 13
Joined: Sat Sep 21, 2019 4:46 pm

Wanted : a ZX81 I/O board extension

Post by YannFr »

Hello,

I'm looking for several ZX81 input / Output board extensions to buy. If you have one or two and want to sell it, don't hesitate to make me an offer by DM.

thanks !

Yann
mcarlson_sb
Posts: 122
Joined: Wed Apr 08, 2020 4:48 am
Location: San Francisco

Re: Wanted : a ZX81 I/O board extension

Post by mcarlson_sb »

Are you looking for old only (like the Maplin kits) or will new be okay also?

Do you have specific interface needs?

Are you looking for pre-made or is kit okay?

I designed some quick extensions and can share the Gerber files if you want to order new PCBs. But you'd have to put then together yourself.
YannFr
Posts: 13
Joined: Sat Sep 21, 2019 4:46 pm

Re: Wanted : a ZX81 I/O board extension

Post by YannFr »

Hello,

I'm interested by old and new items.

No specific interface need : it is just to enhance my Zoo extension of ZX81 stuff. However, I/O digital extension board to manipulate led or relay will be a mut have for some project I have

Kit is okay, pre made also

Great proposal to share the Gerber file

Cheers
Yann
mcarlson_sb
Posts: 122
Joined: Wed Apr 08, 2020 4:48 am
Location: San Francisco

Re: Wanted : a ZX81 I/O board extension

Post by mcarlson_sb »

YannFr wrote: Tue Sep 08, 2020 8:19 pm Great proposal to share the Gerber file
I haven't yet ordered and built the v2 extension board.
And I found an error with the v1 boards I've been using (flipped A and B side pins)

These work fine as dev boards for prototyping.
But, I need to fix it before I can use them to plug a card in.

Once I've checked that v2 works I'll share the files.

Cheers,
Matthew
dr beep
Posts: 1294
Joined: Thu Jun 16, 2011 8:35 am
Location: Boxmeer

Re: Wanted : a ZX81 I/O board extension

Post by dr beep »

you can use this interface layout as base.

You can use the outputlines with a led and resistance to show your output.

https://trastero.speccy.org/cosas/JL/DrBeep/PC-ZX.html
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XavSnap
Posts: 965
Joined: Sat May 10, 2008 4:23 pm

Re: Wanted : a ZX81 I/O board extension

Post by XavSnap »

This card based on a 8255 seem to be a good choice.
viewtopic.php?f=8&t=3837

8 io on the Centronics DB25 socket.
Xavier
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