Search found 6 matches
- Fri Aug 11, 2017 5:22 pm
- Forum: WANTED
- Topic: ZX81 ULA wanted
- Replies: 10
- Views: 9458
Re: ZX81 ULA wanted
I was looking at the thread about a modern ULA thats drops in, sounds promising. Mine is not responding the the keypad, other than that it seems to work.I get the Inverse 'K' on the screen. runs bloody hot those. I have re-soldered all of the IC pins and it made no difference. I may consider getting...
- Thu Aug 10, 2017 7:05 pm
- Forum: WANTED
- Topic: ZX81 ULA wanted
- Replies: 10
- Views: 9458
ZX81 ULA wanted
Before I decide what to do with my 'half dead' ZX81,(see my post in Hardware) does anyone know if there are currently 'any' responsibly priced ULA's available in the UK?
Thanks
Ian
Thanks
Ian
- Sat Aug 05, 2017 2:02 pm
- Forum: Hardware
- Topic: My ZX81 is not respondiung to Keypad
- Replies: 4
- Views: 2135
Re: My ZX81 is not respondiung to Keypad
Thanks.
I will see if there is any activity on all the ULA keypad pins, and check for dry joints. Dry joints can certainly cause problems on old PCB's
I will resolder all of the ULA and Processor pins, The ROM and the RAM must be working for it get the 'K' on the screen.
I will see if there is any activity on all the ULA keypad pins, and check for dry joints. Dry joints can certainly cause problems on old PCB's
I will resolder all of the ULA and Processor pins, The ROM and the RAM must be working for it get the 'K' on the screen.
- Thu Aug 03, 2017 6:28 pm
- Forum: Hardware
- Topic: Unknown 18-pin ULA chip
- Replies: 10
- Views: 4733
Re: Unknown 18-pin ULA chip
It could be the ULA out of the 16K Ram pack, mine has one.. not that it is working. no -5volts
- Thu Aug 03, 2017 6:18 pm
- Forum: Hardware
- Topic: My ZX81 is not respondiung to Keypad
- Replies: 4
- Views: 2135
Re: My ZX81 is not respondiung to Keypad
Should my 'K' be flashing, it has been a long time since I last used it?
mine is not
That may explain why The keypad is not responding!!!!!
Any pointers.
Thanks.
mine is not
That may explain why The keypad is not responding!!!!!
Any pointers.
Thanks.
- Thu Aug 03, 2017 6:02 pm
- Forum: Hardware
- Topic: My ZX81 is not respondiung to Keypad
- Replies: 4
- Views: 2135
My ZX81 is not respondiung to Keypad
Hi, I am new to this forum, so excuse me if this question has already been answered before. I have an issue 3 ZX81, i have bypassed the TV modulator so I can use it with a PC monitor connected through a Composite video to VGA converter. I get the 'K' cursor on the screen, so signs of life. I have ju...