Date   : Tue, 16 Oct 2007 20:28:13 +0100
From   : zeem.uk@... (Alex Taylor)
Subject: Issue 4 freezes in old age

I was wondering about all this. I've got a bunch of faulty Beebs, one
of which seems to work - except an odd video ULA problem.

It's an issue 7 that the original ULA caused random flickering cursor
widths and non-functional 20K modes. My spare ULAs result in an
inverted mode 7 but the other modes work fine - and these spare ULAs
seem to work fine in an issue 4 machine. None of them have ever had
heatsink paste on them.

Does this mean I can modify something on the iss.7 board to make mode
7 work properly with the spare ULAs I have? Or do I need a different
ULA?

The issue 4 used to have a fault where the disk interface would
'disappear' if the machine was left on for a while - but it seems to
work ok now. I used it for three full days in July for a 'retro games'
activity I ran in my school's end-of-year activities week, and it ran
fine.