Sinclair ZX80 / ZX81 / Z88 Forums

When trying to email blittled my backup of Wilf's site, Gmail refused to send the archive (also recipients using Gmail would have been blocked from downloading that .zip as attachment). I narrowed down the issue to a little MS-DOS program called ROMKEY.EXE (contained in ROMKEY.ZIP), which is used in...

Email sent...

Surely closer to 10k than 9k by the time people read this. :lol: A very f***ing &@0!$% bloody hot welcome from the NL, twoangrybears! (heatwave here and all...) I've recently become interested in electronics and digital logic and this has revived my interest in the ZX81 as a machine simple enough th...

I know they would have been expensive, YES. VERY. Remember home computers themselves were expensive back then. Computers that came with floppy drives as standard where mostly XT/early '286 PC's that were even more expensive. Like "business-only" kind of expensive. I just checked.. for example the D...

I think my TV is throwing a wobbly at certain signals and my composite video conversions are just the basic transistor and 2 resistors. Try adding a series capacitor in the output. 47 uF/10V works, 100 uF or a bit more is better. Minus to the RCA connector center pin, + to the transistor side. Mayb...

S@Tech.. never heard of. And I've seen a loooottt of RAM chips in my life. :D Then again it's a very generic chip type so many different manufacturers. Glanced over that datasheet, and didn't spot anything that seemed worrysome. @Mark: with chip pulled, those GND/Vcc lines would also be disconnected...

Hello Erm, (and welcome to this forum ;) ) The RAM chip is a new 62256. Do you happen to know what manufacturer? I don't recognise the logo (which happens to me rarely :mrgreen: ). MM62256 turns up little, HM62256 suggests Hitachi but it's not that? I'd like to check datasheet for that part. You cou...

Yes if you're going for an original Spectrum, then the 128K "toastrack" is probably the model that can run the greatest selection of software. The Amstrad models have much 'cleaner' internals and come with much better keyboards though. There's subtle differences between the toastrack & +2/+3 models ...

Great story there, FortyNiner! And welcome to this forum. :D That was an excellent deal you got there. Guess eBay wasn't seller's cup of tea... :lol: ZX81's are still easy to find, but they are slowly becoming more rare (and more expensive). Haven't seen one on a flea market in years. Anyway seems y...

If you go via the eBay selling route, upwards of £100 if you are lucky. Not much luck needed... ZX80's are going for 'crazy' prices these days. :( Especially if in good nick. Which this one seems to be (compared to some other ZX80's I've seen on offer). I wouldn't be surprised if it fetches £150 or...