Re: commodore 8032 vga / ports to monitor

Hi Steve,

thanks for the information

I guess I should plan some switches...

my main problem is the lack of pins on the propeller I'm almost using 
everything....

I also have a mechanical problem with the vga cable, it has a tendancy 
to remove the board out of the 6502 socket

for the next version I'll use a small connector with a small cable 
connected to the real vga plug

such a wat that if there is a traction the small connector disconnect 
without removing the board out of the 6502 socket






Le 27/02/2018 à 15:47, Steve Gray a écrit :
> The problem with that is both 40 and 80 column screens are configured 
> the same (as 40 column) since the 80-column circuitry does tricks to 
> display 2 characters in the space of one.
> You can identify european vs north american (50/60 hz power) by 
> looking at the timing registers, but not 40 vs 80. You could monitor 
> for writes to screen ram >1024 to indicate 80 column. this would be 
> done at initialization to clear the screen.
>
> Steve
>
>
> ------------------------------------------------------------------------
> *From:* didier derny <didier@aida.org>
> *To:* cbm-hackers@musoftware.de
> *Sent:* Tuesday, February 27, 2018 6:30 AM
> *Subject:* Re: commodore 8032 vga / ports to monitor
>
> thanks for the informations
>
>
> I think I found a way to support from the original pet 2001 to the 8296
>
> I'll configure initially for 40 columns (pet 2001)  mode   (color of the
> screen / level with trim on the board)
>
> then when I receive the crtc configuration I'll switch to the correct mode
>
>
> Le 25/02/2018 à 00:28, Mia Magnusson a écrit :
> > Den Sat, 24 Feb 2018 22:49:37 +0100 skrev didier derny
> > <didier@aida.org <mailto:didier@aida.org>>:
> >> I guess that for my vga board, all I need to monitor
> >>
> >> is the write in CRTC  (to reconfigure the screen emulated in the
> >> propeller)
> >>
> >> and the write in $FFF0 to detect when the screen or I/O area are
> >> shadowed by the 64k extension ?
> >>
> >>
> >> I've not seen anything else in PIA/VIA but I may have missed something
> >>
> >> for me the 8032 it's quite old...
> > There is the "killer poke" that turns the VSYNC detect input to an
> > output. On the oldest PETs the hardware did drive hard enough that this
> > didn't matter but it disabled the timing logic halting the cpu when
> > accessing video ram while video were displayed. On newer machines it
> > messes up VSYNC output.
> >
> > Don't know if there is any use emulating that behavior.
> >
> > P.S. if you want some ideas for feature creep you might want to have a
> > look at the various hires addons for PETs :)
> >
>
>
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