Looking at the disassembly there appears to be additional "registers" at $E882, E888, and E88A which corresponds to the CRTC IO area $E880-E88F. Normally there are only two CRTC registers ($E880 and $E881) and those are mirrored in the $E88x range. There may be decoding on the board that negates the mirroring and decodes these additional registers.I have looked through a couple times and I can not see any writing to any normal memory area, so I'm thinking the graphics ram must be accessed through these "registers" somehow.I do not see any writes to $E800 or $E801 (The CRTC register select and data ports) so it doesn't appear to be using the CRTC to access memory. Steve From: vossi <vossi@ceffy.de> To: cbm-hackers@musoftware.de Sent: Monday, August 28, 2017 1:06 PM Subject: Re: Data Becker CBM-8000 hi-res graphics first tries: $9000 graphics on (shrinks screen vertical to eliminate spaces between char-lines) $9003 graphics off $9006 clear screen $9009 non invert screen $900c invert screen -- View this message in context: http://cbm-hackers.2304266.n4.nabble.com/Data-Becker-CBM-8000-hi-res-graphics-tp4663482p4663488.html Sent from the cbm-hackers mailing list archive at Nabble.com. Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2017-08-29 01:00:03
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