Today we are looking at this #zxspectrum diagnostic board and testing it with 3 faulty #sinclair zx spectrums and a nice collection of chips marked as faulty. The Diagnostic card is based on the work of Dylan Smith and you can find more details at https://github.com/brendanalford/zx-diagnostics/wiki/Firmware

You can buy from myretrostore-uk on ebay

The Diagnostic board has been configured as follows: Page 0 - Dylan's diagnostic 48k ROM v0.1 Page 4 - Flash utility Page 5 - Brendon's diagnostic ROM v0.38 Page 6 - Dylan's diagnostic 48k ROM v0.1 Page 7 - Dylan's diagnostic 128k ROM v0.1

To change the default rom on the card you have to use the firmware util built into the card and that requires a working spectrum. I only covered the first steps and this is how to do the rest

To change to boot ROM: Set page jumper to 2-3 Plug in cartridge Power on Spectrum Enter command: CLEAR 32767 Enter command: OUT 31,36 The flash utility will now load Press enter for other options Press x for erase Select 0 (Erase page 0) When Done, press any key to exit Press enter for other options Press c for copy Select 5 for Brendan's ROM, or 6 for Dylan's 48k ROM or 7 for Dylan's 128k ROM When Done, press any key to exit Press enter for other options Press p for program Press 0 (ROM is written to page 0) When Done, press any key to exit Power off Spectrum. Change page jumper to 1-2 Power on Spectrum and ROM tests will begin.

The version 0.1 rom will test the memory first and then look at the ULA and I think this is useful if the spectrum has no display, but Brendon's diagnostic ROM v0.38 does provide a lot more tests.

Music is from the Youtube library Will 2 Pwr - half.cool Insta Beat Vixens - half.cool Gemini - half.cool

http://www.breakintoprogram.co.uk/

00:00 intro 00:35 first look at the Diagnostic cartridge 02:15 Spectrum with no display just a black screen 04:27 running a complete test with a good ULA 06:14 Spectrum with what looks like a lower ram fault, but has a new lower ram module 09:21 Spectrum with a white screen and border 11:42 Testing with the v0.38 diagnostic rom 12:33 Testing 4 ULA from a friend marked with X and thought to be faulty. 14:33 conclusion