Search found 1432 matches

by Lardo Boffin
Wed Apr 21, 2021 2:19 pm
Forum: Hardware
Topic: Poorly issue two Spectrum
Replies: 16
Views: 892

Re: Poorly issue two Spectrum

Replacing the two RAMs means it now boots fine to the Sinclair logo!

Is there anything else I should check before leaving it switched on for any length of time? Presumably something caused the chips to fail in the first place.
by Lardo Boffin
Tue Apr 20, 2021 5:07 pm
Forum: Hardware
Topic: Poorly issue two Spectrum
Replies: 16
Views: 892

Re: Poorly issue two Spectrum

Erm wrote: Tue Apr 20, 2021 4:52 pm You don't by any chance have a very early ULA spare? I have an issue 1 board with a later ULA and would like to revert it to original (with the Spider mod).
Sorry I don’t have one. I bought this mainly in the hope it would have one being a fairly low serial number!
by Lardo Boffin
Tue Apr 20, 2021 4:32 pm
Forum: Hardware
Topic: Poorly issue two Spectrum
Replies: 16
Views: 892

Re: Poorly issue two Spectrum

Is the broken trace / gap intentional?

9D65155A-E23F-4D0A-827D-B4537091BC99.jpeg
by Lardo Boffin
Tue Apr 20, 2021 2:48 pm
Forum: Hardware
Topic: Poorly issue two Spectrum
Replies: 16
Views: 892

Re: Poorly issue two Spectrum

Looks like it lead an interesting life - pretty sure that isn’t the original ULA (the serial number is 001-057303) and also an interesting daughter board near the Z80. Part of the 48K glue logic?

2ECB171E-6711-47F1-9A22-4376F8303D10.jpeg
by Lardo Boffin
Tue Apr 20, 2021 2:46 pm
Forum: Hardware
Topic: Poorly issue two Spectrum
Replies: 16
Views: 892

Poorly issue two Spectrum

I just got an issue two Spectrum which doesn’t boot, as below. The two lower RAM chips marked with splodges get very hot quite quickly so I’m assuming are faulty? I have a couple of 4116s somewhere but is there anything I should check / change first to avoid them also becoming broken? 7EF8AFF1-9FCC-...
by Lardo Boffin
Thu Apr 15, 2021 10:50 pm
Forum: Hardware
Topic: You’re gonna need a bigger switch!
Replies: 6
Views: 415

Re: You’re gonna need a bigger switch!

Thanks for the kind offer Chris!

I am banished to the garage to solder so with no heating and temps not getting above 8 deg C today it was probably not the best time to try precision operations. I will wait until it warms up a bit and try again.
by Lardo Boffin
Thu Apr 15, 2021 9:26 pm
Forum: Hardware
Topic: You’re gonna need a bigger switch!
Replies: 6
Views: 415

Re: You’re gonna need a bigger switch!

Blimey! You have a very large switch sir! I want a switch that will do the same job as the existing one but is physically larger so I can actually solder it. It will be living in my rebuilt zeddy case so it would be cool if it could be mounted somehow to make it accessible without dismantling the ca...
by Lardo Boffin
Thu Apr 15, 2021 8:23 pm
Forum: Hardware
Topic: You’re gonna need a bigger switch!
Replies: 6
Views: 415

You’re gonna need a bigger switch!

I went to fit another ROMel with multi-ROMs to my zeddy and came to the conclusion the current switch is just too fiddly! I managed to do one a year or two ago but frankly have no idea how I managed it last time. The switch: 4E3CC8A6-FD59-4CA7-B1F9-44FDD30C9CC0.jpeg Zeddy for scale: B0962080-B9EC-45...
by Lardo Boffin
Wed Apr 14, 2021 8:00 pm
Forum: Hardware
Topic: Composite mod issue: left side of screen missing - solved!
Replies: 64
Views: 3637

Re: Composite mod issue: left side of screen missing - solved!

Only anecdotal not technical but I have sold a lot of zeddies with ZX8-CCBs fitted and once tuned (to nearly always the same settings) I don’t need to further adjust them. I always soak test the ones I sell for two lots of 8 hours so would notice any warm up effects. The only thing I have seen once ...
by Lardo Boffin
Mon Apr 12, 2021 10:07 am
Forum: Development
Topic: Dungeon for zx81
Replies: 9
Views: 808

Re: Dungeon for zx81

Its a hard lesson we all learn at some point I think.