[Coco] Wolfenstein 3-D on a 4.77mhz 8088? So, 6809 port, anyone?

Luis Antoniosi (CoCoDemus) retrocanada76 at gmail.com
Wed Apr 24 10:01:02 EDT 2013


 IIRC the original IBM PC-XT had the DMA channel 0 hooked up for DRAM
refresh. I think you cannot make mem2mem transfers on it.


On Wed, Apr 24, 2013 at 9:53 AM, L. Curtis Boyle <curtisboyle at sasktel.net>wrote:

> I don't know if it would be completely impossible. While the 8088 PC's did
> have DMA and hardware divide, their instruction set (especially with memory
> accesses) could be quite a bit slower than a 6809 (or especially a 6309).
> Also, note that in that demo, they were using a Sound Blaster for the
> sound, which would mean a lot less CPU overhead then trying to do it with
> just the 6809. And, lastly, they are using a very small viewing window (to
> even get it to the speed that they do have), which appears to be about 1/3
> the horizontal resolution, and 1/4 the vertical resolution. Since
> Wolfenstein was a 320x200 game, that would mean about 106x50 resolution
> (for the actual 3D rendering).
> And, finally, some proof that this has already been done (graphically as a
> demo, anyways):
> http://www.youtube.com/watch?v=W-Ba2X_AZrI
>
>
> L. Curtis Boyle
> curtisboyle at sasktel.net
>
>
>
> On Apr 23, 2013, at 10:39 PM, Allen Huffman wrote:
>
> > On Apr 23, 2013, at 11:40 PM, Steve Bjork <6809er at srbsoftware.com>
> wrote:
> >
> >> The 6809 is only has an 8-bit ALU but the 8088 has 16-bit ALU. Math is
> more limited on the 6809 because the lack of the DIV instruction.  The 8088
> also had block memory move instructions. Add the fact that most IBM system
> came with hardware DMA for fast memory moves, the CoCo just can't keep up.
> >
> > Well heck. So there was something the 8088s could do. I used to run CoCo
> BASIC versus the same thing on DOS BASIC when I worked at Radio Shack
> (88-90), and it took the 286 model Tandy 1000s to be faster than the CoCo 3.
> >
> > Okay, we can stick to Z80 stuff like Donkey Kong.
> > -
> > Allen Huffman - PO Box 22031 - Clive IA 50325 - 515-999-0227 (vmail/TXT
> only)
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> >
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> >
> >
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