Search found 170 matches

by mahjongg
Tue Sep 17, 2019 2:53 pm
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

Re: I released my ZX81+35 ZX-81 clone design files on Github

Sorry I don’t see the point of yet another replica. There’s already Grant Searle’s version, and ZX96, ZX97, ZX2000. If I would build my custom ZX81 it will probably be ZXNU from ZXTeam. It also uses standard components and has build-in flash drive. Doesn't matter, as I said this is a hobby project,...
by mahjongg
Mon Sep 16, 2019 8:04 pm
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

Re: I released my ZX81+35 ZX-81 clone design files on Github

Well, from the few comments I got I conclude there is not really much enthusiasm to build my ZX81+35 clone, some people even supposing I didn't have a working prototype (but I do, and its working great that is why I have confidence its 100% compatible) . But the reaction I got the most was, its (mos...
by mahjongg
Wed Sep 11, 2019 11:11 pm
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

Re: I released my ZX81+35 ZX-81 clone design files on Github

And this is how the PCB looks, the component side https://revspace.nl/images/7/7a/ZX81%2B35_keyboard_top.png and the solder side https://revspace.nl/images/2/25/ZX81%2B35_keyboard_bottom.png the PCB works with a real ZX-81, or my clone, and its dimensions are such that it will fit in the keyboard re...
by mahjongg
Fri Sep 06, 2019 12:07 am
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

Re: I released my ZX81+35 ZX-81 clone design files on Github

I have drawn the keyboard schematic for my ZX81+35:

Image

I also did the placement, and checked it against my keyboard overlay:

details on my revspace pages.
by mahjongg
Wed Sep 04, 2019 1:56 am
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

Re: I released my ZX81+35 ZX-81 clone design files on Github

Thanks, this exactly conforms to my own conclusion, I already drew a keyboard schematic, but it has D0 to D4 instead of D4 to D0. As soon as I have fixed that error I will release my keyboard schematic. Thanks a lot for the conformation. I now also truly understand that the keyboard layout is NOT up...
by mahjongg
Tue Sep 03, 2019 12:13 pm
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

Re: I released my ZX81+35 ZX-81 clone design files on Github

Thanks, this is indeed a slightly better version that I have, mine misses all the later addendums, and (as far as I remember) had the keyboard diodes in a random order, I have to check it. Still it doesn't indicate pin-1 of both keyboard connectors, so you have to find out the orientation of this by...
by mahjongg
Tue Sep 03, 2019 12:44 am
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

Re: I released my ZX81+35 ZX-81 clone design files on Github

I have made many helpful drawings, the problem is I cannot find any canonical information and have to puzzle it all out myself, and there are pitfalls such as that the ZX-81 keyboard connects to an upside down ZX-81 PCB, and that the canonical schematic does not list the Keyboard address diodes in a...
by mahjongg
Mon Sep 02, 2019 11:54 pm
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

Re: I released my ZX81+35 ZX-81 clone design files on Github

I have now also created a new assembly drawing, for rev 4.0 and uploaded it to GitHub. Here you can see how you should populate the PCB: https://revspace.nl/images/e/ea/ZX81plus35_silkscreen_overview_rev4.png I'm still busy with the keyboard PCB, as not having an error in its wiring is very difficul...
by mahjongg
Sun Sep 01, 2019 1:55 am
Forum: Hardware
Topic: I released my ZX81+35 ZX-81 clone design files on Github
Replies: 18
Views: 4616

I released my ZX81+35 ZX-81 clone design files on Github

After three years I finally decided to release the design files (PCB gerber files etc) of my ZX81 clone ZX81+35 to the world at large. You can find it, (the third major revision of it) on GitHub here: https://github.com/mahjongg2/ZX81plus35. I stopped working on it because I wanted to develop a colo...
by mahjongg
Tue Nov 08, 2016 11:10 pm
Forum: Hardware
Topic: Mr-X Soundcard
Replies: 63
Views: 14418

Re: Mr-X Soundcard

updated the above picture.