Uninitialised custom chip registers in 1.3beta

[darrenfreeman]

I am using "DiagROM V1.3 BETA - 21-Feb-22".

I managed to get a multi-colour vertical bar over the top of every menu and graphics test pattern in DiagROM. It was not cleared on a soft ctrl-A-A reset. It looks like a sprite is enabled, but without DMA. So that gives the vertical bars, which should be 16 pixels wide.

I have seen this a few times already, due to the machine being a bit unstable and crashing.

I managed to get into this state by, on this A4000: enter the "manual memoryedit" tool, goto $dff000. The display will go blank, at least on this monitor. Now ctrl-A-A. The first time I tried it, I had normal operation apart from the enabled sprite. The second time I tried it, however, the display was still blank after the ctrl-A-A, so there must be other registers not being initialised.

Reporting as a general "registers uninitialised" bug, because a power cycle should not be necessary.