Search found 1905 matches
- Mon Dec 25, 2023 10:28 pm
- Forum: Hardware
- Topic: Nominal video output signal on ULA pin 16 ZX81 rev 1?
- Replies: 15
- Views: 1455
Re: Nominal video output signal on ULA pin 16 ZX81 rev 1?
From what I've seen online the sync signal should not be 0v. It’s because the ZX81 does not follow the composite standard. It sends a signal where the difference from bottom of signal to top of signal is ok. Old TVs think this is ok. It does this to avoid making a more complex circuit that sends ne...
- Sun Dec 24, 2023 4:50 pm
- Forum: Hardware
- Topic: Zeddy white screen after memory upgrade
- Replies: 17
- Views: 1699
Re: Zeddy white screen after memory upgrade
This issue around the holidays, is what we call: White Christmas.
- Sun Dec 24, 2023 10:58 am
- Forum: Hardware
- Topic: First zeddy boots but....
- Replies: 19
- Views: 2398
Re: First zeddy boots but....
Why not go full 64k with battery backed up RAM? It’s even possible to replace ROM area with RAM, so you can load your own custom ROMs.
https://web.archive.org/web/20210224003 ... mories.htm
https://web.archive.org/web/20210224003 ... mories.htm
- Sun Dec 24, 2023 10:35 am
- Forum: Hardware
- Topic: First zeddy boots but....
- Replies: 19
- Views: 2398
Re: First zeddy boots but....
If you don’t want to soldier you can get this modern external RAM board:
https://www.ebay.co.uk/itm/116017640518
https://www.ebay.co.uk/itm/116017640518
- Sat Dec 23, 2023 11:11 pm
- Forum: Hardware
- Topic: First zeddy boots but....
- Replies: 19
- Views: 2398
Re: First zeddy boots but....
I have several storage options. But if you have an Arduino, you just upload the firmware for TZXduino, and connect the output pin for Ear to the ZX81. That pulses 5V to the ZX81 from an SD card. That works flawlessly. So find anything that can send outputs that pulses from 0V and 5V. It needs to be ...
- Thu Dec 21, 2023 2:11 pm
- Forum: Hardware
- Topic: Memory Card storage options
- Replies: 11
- Views: 1675
- Thu Dec 21, 2023 12:36 pm
- Forum: Hardware
- Topic: Memory Card storage options
- Replies: 11
- Views: 1675
Re: Memory Card storage options
As a ZXpand might be difficult to get hold of, and import to the UK might be a problem, I would suggest adding a ZX-Wespi to your Zeddy. You'll only need a cheap ESP32 microcontroller and a few resistors and a capacitor. This device stores your programs into the microcontrollers Flash, and you can u...
- Wed Dec 20, 2023 8:32 am
- Forum: Hardware
- Topic: ZX81 floppy disk systems
- Replies: 17
- Views: 6444
- Tue Dec 19, 2023 8:05 pm
- Forum: Sinclair Misc
- Topic: MERRY KMAS
- Replies: 1
- Views: 1406
Re: MERRY KMAS
Thank you for your e-postcard. Marry K-mas to you too.
- Sat Dec 16, 2023 3:54 pm
- Forum: Software
- Topic: Word Processor/Text Editor?
- Replies: 10
- Views: 16292
Re: Word Processor/Text Editor?
Yes. It sounded much alike.