Sinclair ZX80 / ZX81 / Z88 Forums

Once you adjust the ZX8-CCB you should get a really good picture. For later ULAs I start with this position and then fine tune:- 35DC1118-6135-4F8E-B637-8CCB59040850.jpeg Yellow lines added for clarity. ;) Before adjusting I always take a photo of the current position. Very useful when it gets wors...

Isn't that mini-pcb supposed to go into the modulator can? :? (after you rip its contents out). That would very much tidy up the wiring since all signals / power supply you need is right there. Yeah that's right but if someday you want to go back and to get the RF signal it's easy and if do you rip...

Well, finally I have located and ordered an ULA and while it arrives I made a "lifting" to ZX81 bought to @Lardo Boffin. I found a small breakage on the flat cable that goes to the keyboard that has affected 8 keys but fortunatelly a cut with the scissors has been enough to go back to the normallity...

1024MAK wrote: ↑Mon Jun 03, 2019 6:37 am If we hear a shriek of joy from Barcelona, we will know why

Mark

For sure Mark

The only difference in a UK ZX81 and an US TS1000 is the modulator. The ULA does not care. All is handled in software. The ULAs are equal. One connection on the PCB is open or shorted depending on whether it is sold in UK or US. Thank you for the clarification, anyway I'll try to find an ULA here i...

mrtinb wrote: ↑Sun Jun 02, 2019 3:13 pm Here’s one on eBay: https://www.ebay.com/itm/Sinclair-ZX81- ... 672?_ul=DK

Thanks Martin, I have not seen this, but it is the american model I guess, probably from an Timex-Sinclar. I'm not sure if this ULA will be compatible with my Zeddy....

Well, as I was blocked at this point a colleague told me that I can send him the ZX81 and he will check what can be happened. His diagnostic was that the ULA is defective. He swapped a good-know working ULA with mine and once replaced the ZX81 started to work while the other ZX81 failed to startup w...

Hi Andy,

Do you know when a new batch will come?

Thank you!

Murphy's law: After the resonator has been replaced by a new one the problem remains. A new working Zeddy will come soon home and maybe it can help his brother by lending the ULA CPU and ROM for testing purposes. I'll prepare the soler iron because my Issue 3 board has all these parts soldered to th...

Already bought and paid.

Thank you!