Re: Commodore 8296GD

I got some high-res pictures of this board from someone on forum64.de and I was hoping to reverse engineer this board as part of my "UltraPET" project (http://www.6502.org/users/sjgray/projects/ultrapet/index.html). I mention this board on my page.
 
Anyway, this board is refered to as the HRE or High-Res Emulator as it is supposed to be software compatible to the Commodore HSG (High Speed Graphik) board.
I have a web page for the HSG here: http://www.6502.org/users/sjgray/computer/hsg/index.html
 
Perhaps you can try some of the demos I typed in and confirm if they work or not on the HRE board!
 
The CRTC chip can be reprogrammed and I assume that the HRE board bypasses the character set rom and shifts out the actual memory byte as-is. If the character cell height is set to 1 pixel then you effectively have a "graphics" mode.
If the video memory is somehow diverted to the expansion memory that would explain how the normal screen is untouched, and makes sense. It sounds like a cool board.
 
I'd love to get this board cloned!
 
Steve


>________________________________
> From: Michał Pleban <lists@michau.name>
>To: "cbm-hackers@musoftware.de" <cbm-hackers@musoftware.de> 
>Sent: Saturday, September 29, 2012 8:59:45 AM
>Subject: Commodore 8296GD
>  
>Dear all,
>
>>From time to time I collect 8296D computers at eBay, mostly to strip
>internal drives from them for my 700's :-)
>
>Today I repaired one 700, so I went to a 8296D which has been sitting
>idle for many months to strip the drive. Upon opening it, I saw an
>additional board attached to the motherboard, piggybacked on the CRTC
>and character ROM.
>
>>From a short mention on Andre Fachat's website I reckon it must be the
>8296GD cariant, with a hi-res graphics adapter. The "adapter" is
>actually just a small board with a 6545, EPROM, 8 TTL chips and 4
>DIP-switches.
>
>There are these ROMs in this machine:
>
>324243-04 8296D DIN
>324993-02 HiRes BASIC
>324992-02 HiRes Emulator
>824242-01 DIN8296/8296D (in the video board)
>
>The computer powers up, emitting strange beeps from the buzzer, and
>displays standard BASIC 4.0 welcome message. The keyboard has some keys
>missing unfortunately.
>
>I haven't been able to find any documentation on this graphics card and
>I don't know how to utilize it from the BASIC. I will dump the ROMs and
>try to look at them, but maybe someone has documentation scanned which I
>could look at?
>
>Regards,
>Michau.
>
>
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