Search found 3368 matches

by Moggy
Wed Jul 17, 2024 3:15 pm
Forum: Hardware
Topic: ZX81 First line of display distorted
Replies: 22
Views: 14373

Re: ZX81 First line of display distorted

Hi Didier, is it possible to tell us which ULA you have fitted? The early 2C158 version was known to cause a bending of the first line once it got hot, I had 3 which did exactly that even with a composite video board fitted and I found a change to either a later ULA ( 2C184 or 2C210) or modern repla...
by Moggy
Tue Jul 16, 2024 5:25 pm
Forum: ZX BASIC
Topic: ZX81X2.ROM - and the big bang
Replies: 77
Views: 90018

Re: ZX81X2.ROM - and the big bang

In an earlier post I said that when using my logistic equation program, that the Big Bang ROM was throwing up incorrect results. After much online calculator checking plus various maths web sites it now appears that it is the Sinclair ROM maths routines that are erroneous in this regard and in fact ...
by Moggy
Tue Jul 16, 2024 1:00 pm
Forum: Hardware
Topic: TS1000 Diagnostic Help
Replies: 32
Views: 3484

Re: TS1000 Diagnostic Help

Great to hear you have had some success at last, long may it continue! :D
by Moggy
Tue Jul 16, 2024 12:33 pm
Forum: ZX BASIC
Topic: ZX81X2.ROM - and the big bang
Replies: 77
Views: 90018

Re: ZX81X2.ROM - and the big bang

Tried the ZXPAND command as follows..

ZXPAND "DELETE TF79.P" and it worked just fine (I did restore TF79 later!)
by Moggy
Mon Jul 15, 2024 8:43 pm
Forum: ZX BASIC
Topic: ZX81X2.ROM - and the big bang
Replies: 77
Views: 90018

Re: ZX81X2.ROM - and the big bang

I used v 1.40 of EIGHTY one with the 66x2c ROM and whilst it works the CONFIG "X" command caused a crash. I haven't tried the other ROM in a later version of Eighty One as I'm only interested in real kit but would assume that the72x2c would work the same way with a later copy of the emulator.
by Moggy
Mon Jul 15, 2024 8:34 pm
Forum: ZX BASIC
Topic: ZX81X2.ROM - and the big bang
Replies: 77
Views: 90018

Re: ZX81X2.ROM - and the big bang

As promised I have programmed a 2764 EPROM, fitted it to one of my classic spands and yes it works just as it should even the CONFIG "X" command works unlike when I tried it in Eighty One. So yes works OK and especially useful to owners of issue 3 computers where the ROM is usually soldered to the b...
by Moggy
Mon Jul 15, 2024 12:41 pm
Forum: Hardware
Topic: TS1000 Diagnostic Help
Replies: 32
Views: 3484

Re: TS1000 Diagnostic Help

If you don't wish to remove the socket you could at least try re-flowing the solder joints. some of the pins make contact on the top side of the board so perhaps check and see if these look solid. In my own actual experience with the ROM socket I always ended up either replacing or soldering the chi...
by Moggy
Mon Jul 15, 2024 12:32 pm
Forum: Hardware
Topic: Alphacom 32 / TS 2040 Repair Help
Replies: 3
Views: 326

Re: Alphacom 32 / TS 2040 Repair Help

I once read somewhere that Memotech RAM modules needed a certain DIP switch setting to work with the Alphacom but cannot swear to the truthfulness of it,Sinclair's module should be OK though. The Alphacoms are generally very robust and as the self test is producing actualprint then I would say the a...
by Moggy
Mon Jul 15, 2024 12:18 pm
Forum: ZX BASIC
Topic: ZX81X2.ROM - and the big bang
Replies: 77
Views: 90018

Re: ZX81X2.ROM - and the big bang

Found the solution! v72x2c causes the garbage for me in Eighty One but v66x2c works however CONFIG "X" causes a whiteout, I tested it to see if the "PAUSE" stutter was present after a screenful of CHR$ was SCROLLED and no stutter present and the CLS cleared the screen instantly so looks like the imp...
by Moggy
Mon Jul 15, 2024 12:05 pm
Forum: ZX BASIC
Topic: ZX81X2.ROM - and the big bang
Replies: 77
Views: 90018

Re: ZX81X2.ROM - and the big bang

No luck I'm afraid as this is what I get with the renamed ROM in Eighty One.