On Thu, 07 Oct 1999, MkII wrote:
> Is it at all possible to issue high speed VDP commands in
> character-oriented video modes?
On V9958 (MSX2+/tR) there is a bit that enables the use of VDP commands in
non-bitmap modes. It's register 25, bit 6.
According to my info, it allows command use in SCREEN 2-4. Nothing is said
about SCREEN 0 and 1.
> If not, what's the actual result? Perhaps some useful tricks could be devised.
Commands act on the VRAM as in SCREEN 8.
On V9938, commands in non-bitmap modes are not supported. I don't know what
happens if you try. Maybe nothing happens. Maybe strange things happen.
Maybe it works.
Commands may be useful to make the screen scroll. But if it's V9958 only,
the use is limited.
Note: I never actually tries this. I do have both a V9938 machine (8250)
and a V9958 machine (GT) here, so if you want me to run some tests, just
mail the programs I should run.
Bye,
Maarten
****
MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put
in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the
quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
****
