Search found 387 matches

by David G
Wed Nov 16, 2022 7:09 pm
Forum: Development
Topic: Run Machine Code in High Memory
Replies: 8
Views: 4407

Re: Run Machine Code in High Memory

Yes, the Timex/Sinclair 1000 is a ZX81, using a ZX81 UK motherboard fitted with the optional 2K RAM chip and jumpered for 60hz television. The ROM is the same as a ZX81 The articles Rich uploaded are no longer available at that link, but from his description seem to be from SyncWare News Volume 2 no...
by David G
Wed Nov 16, 2022 3:47 am
Forum: SALES
Topic: ZX81 on ebay.
Replies: 1
Views: 1283

Re: ZX81 on ebay.

wow, a time capsule Sold: 55 pounds ZX81 with Games, manuals and RAM Pack - TESTED & WORKING a.jpg looks like * ZX81 with ZX POWER SUPPLY, video cable & cassette cables * ZX 16K RAM pack Tapes * sinclair ZX81 SPACE RAIDERS by PSION * 16K TUT-TUT by CRONOSOFT * sinclair ZX81 CHESS-CLOCK by PSION LTD ...
by David G
Wed Nov 16, 2022 3:08 am
Forum: Lambda 8300/ Power 3000 Lounge
Topic: 😲😞
Replies: 14
Views: 13065

Re: 😲😞

Does this Lambda Colour Pack work as an attachment to the ZX81, or is it strictly designed to be used with the Lambda 8300?
by David G
Mon Nov 14, 2022 12:51 am
Forum: Welcome Area
Topic: Hello from Zeeland
Replies: 8
Views: 2188

Re: Hello from Zeeland

wow first i hear of Bang & Olufsen ZX81 Beocomp, it would look good next to the B&O record player

Image
photo Mark NL via wikcommons

It looks like standard-issue UK ZX81
by David G
Thu Oct 27, 2022 3:55 am
Forum: Hardware
Topic: Sinclair SCL/ULA
Replies: 14
Views: 7750

Re: Sinclair SCL/ULA

thanks. I have edited that post to remove the socket information. It was old info collected from prior posts on this forum
by David G
Wed Oct 26, 2022 11:38 am
Forum: Hardware
Topic: Sinclair SCL/ULA
Replies: 14
Views: 7750

Re: Sinclair SCL/ULA

Thanks! Now edited to say "Chapter 25" instead of "page 25"

you have eagle eyes :o
by David G
Wed Oct 26, 2022 11:30 am
Forum: Hardware
Topic: Full-travel mechanical keyboard - No mods to ZX81
Replies: 1
Views: 567

Full-travel mechanical keyboard - No mods to ZX81

I spent many hours typing away on the original ZX81 keyboard and had no problems with it. Even if it lacked tactile feedback, I was quite happy with it, it worked fine at a minimal level Even so, back around 1985 I added a surplus full-travel keyboard. I bought it as i recall at an automotive swap m...
by David G
Wed Oct 26, 2022 9:24 am
Forum: Sinclair Misc
Topic: Repurposing the ZX81 Keyboard
Replies: 6
Views: 3109

Re: Repurposing the ZX81 Keyboard

Regarding the title of this topic ("Repurposing the ZX81 Keyboard"), my initial thought was why would you want to do that? That's a hack. But i recognize there is utility in a small, flat, lightweight keyboard. For a while I carried around a foldable neoprene travel keyboard to use with my PC. This ...
by David G
Wed Oct 26, 2022 8:42 am
Forum: Hardware
Topic: Sinclair SCL/ULA
Replies: 14
Views: 7750

SCL/ULA links

sinclairzxworld site search Deep dive on the 2C184E SCL explains all the functionality and includes equivalent circuit diagrams New/replacement ULA where to find. Are they still available? Making a new SCL from a CPLD chip and Andy Reas's improved ULA from a CPLD ULA heat issues . Should I get a he...
by David G
Wed Oct 26, 2022 8:21 am
Forum: Hardware
Topic: Sinclair SCL/ULA
Replies: 14
Views: 7750

ULA Versions

The ZX81 SCL/ULA comes in three versions. All these SCLs interchange, but the last one has an improved video signal circuit 2C158E is the earliest version 2C184E is the middle revision. No significant difference from 2C158 2C210E has the video back porch signal, for better compatibility with more ex...