A reset button i wanted on my keyboard required some schematics, in case i make a non-volatile RAM later, here it is:
Hello from Moscow
Re: Hello from Moscow
Right now i am almost ready with my ZX81, everything works as expected. Keyboard needs it's case finishing, i will do it later.
One problem is i could not find any single 32K RAM upgrade shceme that does not have any drawbacks.
I have collected 10 or 15 schematics, most by Wilf Rigter, some modifications, but neither of them suits my needs. Wilf's mods look nice, but as Siggy on german forum said, they have glitches with modern RAM chips. There are some instability problems with M1 NOT mods either.
I have already spent eur50 or 70 on chips and components for different RAM mods, yet have not made a final decision on the RAM upgrade model. But i certainly want 32K at least, because i saw a couple of games (Super Star Trek) that demand 32K RAM.
Also, i have some more ideas or mods:
One problem is i could not find any single 32K RAM upgrade shceme that does not have any drawbacks.
I have collected 10 or 15 schematics, most by Wilf Rigter, some modifications, but neither of them suits my needs. Wilf's mods look nice, but as Siggy on german forum said, they have glitches with modern RAM chips. There are some instability problems with M1 NOT mods either.
I have already spent eur50 or 70 on chips and components for different RAM mods, yet have not made a final decision on the RAM upgrade model. But i certainly want 32K at least, because i saw a couple of games (Super Star Trek) that demand 32K RAM.
Also, i have some more ideas or mods:
Re: Hello from Moscow
Some nice pics of my ZX81 in it's current state: