Wow, after 20years+ they worked first time! I ran many different Games/Demos/TestTools on both machines. Here are my screenshots:

ZX 48+ testing

ZX 128+2 testing

- On my 48k when running DarkStar, I repeatedly toggled between the menu and hiscore table. The border pattern was mostly in the same place where the yellow border section would begin/align just after the 'k' of the "Dark Star" title. Except for about 1 in 10 times where The yellow border section would begin/align just after the first 'a' of the "Dark Star" title. On my 128k, although the border pattern is naturally skewed, it is always in the same place regardless of how many times I toggle between menu and hiscores. Screenshots of all these scenarios can be found in the albums above.

- Qarx hiscore screen looks perfect on my 48k (No strange artifacts at the very left side of the border). However, the border width of my actual 48k is noticeably thinner than mame's. Just a hunch at the moment, but I suspect that mame is showing more (too much) border than was actually possible back in the day and that is why I am seeing the strange artifacts. Searching on the web for other peoples screenshots of actual spectrums running and their border width looks the same as mine (So I do not think its just my 48k that has an unusually thin border). Also, it appears mame shows more border than the other spectrum emulators I've tried (Emuzwin/fuse), which is interesting.

- The Contended memory / floating bus test problems I found here Speccy tests
btime.tap (border time test) and stime.tap (screen time test) draw a small red line either in the border section or the screen section of the display. Where it is drawn depends on when the opcode writes (that set the red border/screen colour on and then off) occur. Using the 'q' and 'a' keys, you are able to adjust the timing of when the opcode writes occur, thus effect where the red line appears. I took plenty of screenshots when running btime and stime for various tstates.

Next step is to make sure these test results tally up with my mame mods smile