Date   : Sun, 22 Apr 2012 00:13:38 +0100 (WET-DST)
From   : BBCMICRO@... (Peter Coghlan)
Subject: Video Problems

>
>MODE6:!&6200=-1 gives a mode 6 size cursor at the top left of the screen
>

It should result in a white block slightly taller than a mode 6 cursor, not
flashing, one line down from the top and about two thirds of the way across
the screen.

The idea was to try to find if when attempting to write characters, the OS was
failing to update screen memory or it was successfully updating screen memory
but the contents of memory was not having an effect on the screen. It seems
the latter is the case but the test is hardly conclusive.

I wonder does output to the printer work? (with the user VIA back in or
using a serial printer.) That would make it possible to peek values in screen
memory and verify they are correct.

In mode 6, something like VDU 19, 1, 0, 0, 0 would seem to produce a similar
effect. However, this would not explain having the same problem in mode 7.
I don't suppose VDU 19, 0, 4, 0, 0, 0 does anything useful in mode 6?

>
>And it's new and unknown unfortunatly... 
>

Bummer :-(

Regards,
Peter Coghlan.