Page 1 of 1
Wanted : a ZX81 I/O board extension
Posted: Mon Sep 07, 2020 8:57 pm
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
Re: Wanted : a ZX81 I/O board extension
Posted: Mon Sep 07, 2020 11:14 pm
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.
Re: Wanted : a ZX81 I/O board extension
Posted: Tue Sep 08, 2020 8:19 pm
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
Re: Wanted : a ZX81 I/O board extension
Posted: Wed Sep 09, 2020 5:56 am
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
Re: Wanted : a ZX81 I/O board extension
Posted: Sat Sep 12, 2020 1:03 am
by XavSnap
Re: Wanted : a ZX81 I/O board extension
Posted: Sat Sep 12, 2020 10:01 pm
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
Re: Wanted : a ZX81 I/O board extension
Posted: Wed Sep 23, 2020 6:13 pm
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.