Sinclair ZX80 / ZX81 / Z88 Forums

If your ULA is a known Good one, and you install the New CPU and still get No Cursor (K) it could be the ROM. (Smaller Chip between ULA and CPU) As this stores all the ZX81 Machine Language and working Memory. I do have 1 Working Spare ZX81 ROM I could part with, if needed. It is currently in a ISS ...

Don't Believe Everything you Read...

Apparently "Hitlers Plane" was found on the Moon!

Or so the "SUN Newspaper" Reported years ago... anyone remember that? It even had a Picture!

Darren (amigaman07)

I would Temp. Dis-Connect the Composite MOD, Re-Install the RF to see if Issue goes away. If still Lines and so-on, try Removing and Re-Seating the ULA, sometimes it is a Bad Contact. If ULA looks a little corroded on the Legs, give it a light Sand and WD40. (Make Better Contact)! Sometimes it is th...

Already Paid for Mine!!! "backer 1711"

Arriving in January 2018...

... there goes another Finger Nail

Darren (amigaman07)

Hi all. Sorry to hear it has come to this already, especially when i just Joined up! (DOH!) Oh, and Hi Rich, (Your Bud here from Sunny OZ ;) ) Hope this finds you all Well, and watch out for those Busses, you can wait all Day for a Bus then 5 come at Once! (Try Dodging that Barrage) :roll: I am a bi...

Uh, What???

Do you also have a Lipstick Trick?

Darren (amigaman07)

Oh, RE the Plug in RAM Packs. These can seriously get the Wabbles, and can Kill ZX81's with the Bad Contacts. A Good Trick is a Strip of Velcro Tape on the Back of your ZX81, and Plug Home the RAM Pack. When the Other side of the Velcro Sticks to the RAM Pack, it makes a Great STABLE Connection, no ...

From my ZX Spectrum Experiences, it is Likely to be a DEAD or Very Sick ULA! Always the 2nd thing to Die on a ZX Speccy, after the Low or High RAM! Try the DUFF ULA in a Good Known Working ZX81. (Not the other way round!) Don't put your Good ULA in the Dead Machine, there may be a Reason your ULA Po...

Hi mark. My First Ever Computer was a ZX81, way back in 1984 ! Mum refused to Buy me a Computer, as they were too expensive for a Single Mum with 4 Kids, so I had to Save up all my Pennies to Purchase 1. (I was 14 at the time and could Not Afford a ZX Spectrum) I Traded in my "INTELEVISION" for the ...

Hi again ZX81 Fans. OK, I had a look at this COMPOSITE Out on my Spare Working TX 1000 (ZX81). This is an "ISS 3" Mainboard. The Gold Socket, I assumed was Composite Out, is actually an additional RF Out. Re-routed around the Modulator for Some reason, maybe for the use of a 2nd TV (2 x TV's in use ...