[Coco] new high density controller
lamune at doki-doki.net
Thu Aug 10 16:49:20 EDT 2006
jdaggett at gate.net wrote:
> The 2793 has internal clock divide. This would allow the switch between HD
> and DD drives. It will not allow the use of 1.2 Meg floppies.
> Using the 2797 and an external clock divider will allow use of 360K, 720K,
> 1.2 M and 1.44M floppies.
> You don't need two contrtoller chips. Yes you still have two adjustment pots.
> Once set, they should not require frequent adjustments. The Intel 82077AA
> should be the chip of choice if you desire no adjustments of pots. Though
> major rewrite of the Disk basic is needed to communicate with this chip.
If I'm going with the 2-chip solution, why bother with the 2797? the
1773 is far easier to deal with.
I have no intention of rewriting disk basic. There's no point in my
opinion. Sure, nothing would stop the end user from utilizing the Intel
controller in their own programs, but the only benefit would really be
for OS9. Hacking DECB into working with HD disks is really kind of
The only function of the dual-chip solution is to provide a
backward-compatible interface for legacy use, but provide a more modern
interface for OS9 in the same physical package.
I do agree with the person who's into the USB idea. I think that would
be the ultimate solution. Put your .dsk images on a FAT-formatted USB
card, plug it into a controller that emulates the WD1773. That's really
the ultimate solution.
What I'm doing here is really just for fun, mainly to see if I can do it.
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