New member saying hello!

[Rich G]

Hi All,

Thought I'd drop a quick line to say hi. I think I recognise a few names here from other quality establishments.

Just returning to the Zeddy 81 scene after (umm... ) 33 years or so.
Yesterday I took delivery of a fairly inexpensive ZX81 complete with Memopac 64K. Both are in very good cosmetic shape and bought for £10.
Love the build quality of the Memotech - only had the standard Sinclair 16K back in the day.

Haven't been able to check out the memory yet as my TV refused to lock on to a signal - I'm getting an inverse white character on black background.
No matter - I'll sort out a composite mod. The keypad seems fine thankfully.

Anyway, opened the ZX81 up and found that it's an Issue 1 with the square root bug fix piggyback. ULA just has a 4-digit date code printed on it.
I know that there have been at least a couple of threads about this, but does anyone know how many of these were actually made? Rare or not so much?

Anyway seems like a pretty good buy for a tenner?

Nice to be here.

Richard.

[RWAP]

A good buy for a tenner - certainly the Memopak is worth more than that...

The very dark display sounds as though you have a ULA with a missing back porch - this can only be fixed by 4 methods:

a) Using an old black & white TV
b) Buying and fitting a replacement ULA (or ZX-ULA2)
c) Buying and fitting a ZXVid in the place of the TV modulator
d) Buying and fitting a ZXCCB

A composite video modification will unfortunately not fix this problem on its own (although if you are lucky, it may if it is actually your TV not locking onto the signal).

Hmm - how many were sold?

Over 1000 as I have sold that many keyboard membranes since 2010....

I don't think there were a million sold (unlike the Spectrum) - but could be wrong...

[Rich G]

Hi Rich,

Thanks for the reply.

Yes I was thinking of the ZXCCB when I said composite mod. Hopefully that will sort things out.

The question of quantity was related to the ZX81 with piggyback mod soldered on top of the Z80 to fix the (ROM Basic) square root bug. This was a factory fitted mod for the very early releases of the machine.
Neat fix but I can't imagine they would have issued too many of those? It would have been a major pain to manually solder for many units.

*edit*
Same as shown here:
viewtopic.php?f=7&t=911

[1024MAK]

Welcome on board Richard!



Mark

[yerzmyey]

We have got the second Rich then?

Well, welcome aboard and congratz on Your new ZX81. 64K - that's fairly unusual (32K become a standard some time ago, thx to SirMorris).
And for games it's still 16k (which is good in my opinion).

Surely You should get Yourself a ZonX. Mr-X and ZXpand-AY.