Wanted : a ZX81 I/O board extension

[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]

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]

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]

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

[XavSnap]

http://zx81.tlienhard.com/phpBB3/viewto ... f=2&t=3440

[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

[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.