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Re: Zeddy displaying wrong characters on screen

Posted: Sat Mar 02, 2024 12:07 am
by Lardo Boffin
Moggy wrote: Fri Mar 01, 2024 11:19 pm
Lardo Boffin wrote: Fri Mar 01, 2024 8:58 pm Guess the program!


IMG_5789.jpeg


Running through the ChromaSCART.
10 PRINT "HELLO WORLD"
20 GOTO 10
Close but not quite enough letters! It is

10 PRINT “HELLO SINCLAIR ZX WORLD”

Re: Zeddy displaying wrong characters on screen

Posted: Sat Mar 02, 2024 12:11 am
by Lardo Boffin
Moggy wrote: Fri Mar 01, 2024 11:17 pm A cell from a de-capped 2c184 ULA, the second picture is a cell with the overlay from Sinclair.

I've had one or two that partially failed, membrane keyboard presses causing a crash but with a Memotech plugged in all ok.
Replacement of the ULA cured it so not a board fault.
Great photos!

I have ‘The Spectrum ULA - How to Design a Microcomputer’ book - a really good read! If a little hard going in places if you don’t have an electronics background.

Re: Zeddy displaying wrong characters on screen

Posted: Sat Mar 02, 2024 7:34 am
by msknight
Yes, it is a bit crazy... we digitise so much analogue stuff only to find that the digital processes are running on an analogue system :-)