Yes.
For testing without any expansions, depending on the H/N ROM selection link positions, you can you just put a 27128 EPROM on the ROM socket.
However to do it properly so that there are no problems, see this web page
Mark
Search found 5165 matches
- Sun Jun 02, 2024 8:14 pm
- Forum: Hardware
- Topic: sinclair spectrum eprom swap gone wrong
- Replies: 2
- Views: 104
- Sun Jun 02, 2024 8:24 am
- Forum: Hardware
- Topic: Is serial from the cassette ports possible?
- Replies: 6
- Views: 275
Re: Is serial from the cassette ports possible?
Given there are some spare unused sections of the chips, RTS, CTS could also be implemented very easily
Mark
Mark
- Sat Jun 01, 2024 7:19 pm
- Forum: Hardware
- Topic: Is serial from the cassette ports possible?
- Replies: 6
- Views: 275
Re: Is serial from the cassette ports possible?
Serial input is possible without too much difficulty, as if needed, a connection can be made to the ULA pin. it is also possible to borrow the ULA UK/USA detection input. Serial output is a bit more tricky, as the ZX81 borrows the video output pin on the ULA to produce the tape (Mic) audio output. T...
- Fri May 31, 2024 5:03 pm
- Forum: Hardware
- Topic: uses for the zx80/81 outside of games
- Replies: 8
- Views: 392
Re: uses for the zx80/81 outside of games
Oh, nearly forgot. A UK TV station (Channel 4 IIRC) and a UK Electronics magazine used a ZX81 as the intelligent controller for a floor robot. Yes, it was for Channel 4 and the magazine was "Electronics - The Maplin Magazine" . Screenshot_20240531-160615.png Here's a link to a pdf of the relevant c...
- Fri May 31, 2024 12:25 pm
- Forum: Hardware
- Topic: uses for the zx80/81 outside of games
- Replies: 8
- Views: 392
Re: uses for the zx80/81 outside of games
Oh, nearly forgot. A UK TV station (Channel 4 IIRC) and a UK Electronics magazine used a ZX81 as the intelligent controller for a floor robot.
I’ll see if I can find a photo.
Mark
I’ll see if I can find a photo.
Mark
- Thu May 30, 2024 11:16 pm
- Forum: Hardware
- Topic: uses for the zx80/81 outside of games
- Replies: 8
- Views: 392
Re: uses for the zx80/81 outside of games
Some of my Zeddies came from a training collage. Unlikely they were only used for games.
Mark
Mark
- Thu May 30, 2024 3:53 pm
- Forum: Hardware
- Topic: Data 2000 case ...I think!
- Replies: 2
- Views: 2733
Re: Data 2000 case ...I think!
The photo that spinner72 was trying to post is this . Or use the provided BBcode: [url=https://ibb.co/C28XGf4][img]https://i.ibb.co/Sry1CzH/Data2000.jpg[/img][/url] Like this: https://i.ibb.co/Sry1CzH/Data2000.jpg As this is a web page and not just a picture (in a format that the forum software reco...
- Wed May 29, 2024 12:37 pm
- Forum: Welcome Area
- Topic: Greeting from the UK. Coding again for the Zx81
- Replies: 7
- Views: 413
Re: Greeting from the UK. Coding again for the Zx81
Hello and welcome to our forum RS232!
I hope you enjoy this forum
Although I notice you actually joined some time ago
And thank you for contributing
Mark
I hope you enjoy this forum
Although I notice you actually joined some time ago
And thank you for contributing
Mark
- Wed May 29, 2024 2:58 am
- Forum: Development
- Topic: Does a specy membrane work on a zx81?
- Replies: 2
- Views: 233
Re: Does a specy membrane work on a zx81?
No and yes. The keyboard matrix is the same, but the order of the signals on the membrane tails is different. Plus the location on the boards for the connectors for the tails is different. So if you use separate connectors and add your own wiring so you can change the order of the signals, yes. Mark
- Tue May 28, 2024 12:32 pm
- Forum: Hardware
- Topic: Timex Sinclair 2068 - Troubleshooting
- Replies: 3
- Views: 505
Re: Timex Sinclair 2068 - Troubleshooting
U1 (µA78S40), Q1 (D432C1), CR1 (1N5821), the inductor L2 and associated components form a buck converter (step-down DC-to-DC converter) which decreases and regulates the output voltage to a set amount. It has the limitation that often a fault with it will result in nearly the full input voltage bein...