Sinclair ZX80 / ZX81 / Z88 Forums

Hey all, me again. If I've got a 32k RAM chip (62256) installed on my replica board. What are the best settings to use on the vla81 to get the most out of it? I'm having a bit of trouble deciphering the memory modes and the soft mod settings. At the moment my vla81 is set to Mode 1 of the memory. US...

Hi All, About four weeks ago I decided that I wanted a ZX81 in my collection but couldn't really find one that I liked So I had a look round for a replica board. I found the likes of the Mahjongg ZX81+38 and the Wilco2009 boards but I wanted more of a replica board that was laid out more or less the...

Hi All, My name is Brett and I'm from Bradford in the UK. My ZX81 journey has just started, I've built a replica of the ZX81 found on github by a member called BlueScreen2001. It is more ornless a replica of an issue one board with a few modifications I.e to allow a 32k RAM chip to be used without h...

Hi All, I was just wondering if anyone has undertaken the task of seeing if they can recreate the styli that come in the ZX printer. If they did did they come up with a template or anything? I need to make some for a X printer I've bought off ebay as spares or repairs. I've got a belt just need the ...

I can confirm that the toothed "switch" or what ever you want to call it does alter the print quality/alignment. I have two Alphacoms and not afraid to experiment, moving the toothed thingy side to side slowly whilst printing does alter the print alignment. as for your other problem sorry I have no...

It’s definitely not the ZX Spectrum. Both the ZX81 and the ZX Spectrum use the built in support in the BASIC ROM to send the correct bit pattern in a serial data stream to the printer. The Timex Sinclair 2040 and the Alphacom 32 printers receive the same serial data stream intended for a ZX Printer...

Hi, Sorry, it's not the Spectrum. It the printer alignment needle start. There is a decay with the first or the second printing needle. printer.jpg You had to check both printing needles and check if it touches the metallic shield at the right timing. At least one needle must be bent. Hi, Apologies...

Hi Brett, It's not a printer problem. The Spectrum don't target the IR register to the UDG memory. (48kb offset) The ROM isn't set to a 48k memory ram set up and picking up UDG data in a wrong location. Spectrum only sends dots, not the real character. Try a COPY, but try to move(copy) the UDG arra...

1024MAK wrote: ↑Sun Aug 14, 2022 12:33 am It may also be a mechanical problem.

Mark

Hi,

What would be the first thing to look at to try and solve this puzzle??

Regards,

Brett

1024MAK wrote: ↑Sat Aug 13, 2022 11:57 pm Yes, it could either be one of the chips, or a poor connection affecting the data.

Mark

Hi,

I hope it isnt one of the IC's that run the print head. They are difficult to get hold of now and I don't know of an alternative.

They are all UCN4401A chips

Regards,

Brett