Sinclair ZX80 / ZX81 / Z88 Forums

ahh. aka the zero force socket
well, i think they have one drawback - the contact area with flat contacts socket is a lot more.

Ummm, what is "turned pin IC sockets"?

Ladies (if any) and Gentlemen! Behold: Da phaquing shit! Literally. So, before going to bed before tough monday i decided to torture my poor zeddy once again so i can gain a lot more data on the problem with my o-scope. Basically, i decided to replug a ram pack to provoke the problem and then check ...

gozzo, i alreay consider this zeddy fully working until rampack is plugged, after that it takes time to recover and again is fully working, well, 95% of the time i guess. i have already checked power ripple down to a few nanoseconds/div with my digital scope. Though, i am limited to 150mhz sampling ...

I tested the rampack for short cicuits - no, all R are very high on all connections. The lowest i saw was about 1.5K between +9 and GND. I don't know about an IC fault. Well, for example a fault inside an IC is triggered. Then why it does not go away after i turn everything off and wait for a night ...

Okay. The weirdness continues. So, here is the noise picture (the forum is over quota on attachment btw) and the picture of the clock on CPU. NOISE http://www.artem.ru/zx81/p2/zx81-noise.jpg CLOCK http://www.artem.ru/zx81/p2/clock.jpg So, by modern standard the clock is bad, but by standards of 80s ...

I have desoldered C5 and measured it. C=1uF, ESR=11. Anyway, i replaced. R15 is 327 Ohm, so, it is fine. Then i decided to plug the pack again and check the voltages and signals. I got white screen. I unplugged the packs and when i turned on i saw the noise like this: http://youtu.be/6cjrjXWOsRI I t...

Okay, my fight for zeddies survival continues. I have found one interesting thing. It appers, that that zx81 i used to test the ram packs and svideo board is a bit strange. When i turned it on (plug the power connector) it does not always turn on fully. I have the video board always connected becaus...

Sysinfo.p will give you a quick answer ;) Oh! This is nice! Thanks RetroTechie : I got it , i got it. Repairing the ram pack is not worth it. But the thing is one of the zeddies i have is a complete boxed set, even the ramp pack is in an original box. So, this is not the functional repair, it is ba...

For spectrum replacing wirg 4164 works fine. So, it should here.

I have a somple question: How do i check total available memory in zx81 basic?