[Coco] Word-PAK RS Clone

[Gene Heskett]

On Sunday 13 August 2017 03:23:37 CoCo Demus wrote:

> Here, fresh from the press:
>
> https://sites.google.com/site/tandycocoloco/wordpak-rs

Good for you! But your clone was too accurate.

That $FF76 address means it straddles the boundary between 2 of the coco3 
std 4 byte blocks of i/o. The one I still have, has been moved to $FF78, 
and my driver adjusted to compensate, so the offsets for the various 
registers are not 0,+1,-1,-2 as in the OEM driver, but 0,+1,+2,+3 which 
puts it all in one block of i/o, which the coco3 is criminally short of.

This is why I have gone off on a rant several times begging someone to 
design an aftermarket decoder board kit to go into the coco3, freeing up 
the space from $FF04-$FF1F, 7 4 byte wide blocks of i/o, and from 
$FF24-FF3F, another 7 4 byte wide blocks of i/o.  Thats 14 more 
accessory cards that could be built if their address decoding was full 
to the 4 byte level, that could be designed, and plugged into the mpi or 
a clone of it, without encountering the dreaded "but that address is 
already used by card x" syndrome. Same idea with the floppy controller, 
which in its current OEM configuration, needs a 5 byte wide space, but 
that would free up 6 more 4 byte wide spaces. A better FDC could 
probably fix that and with a 512 byte buffer, could allow an FDC that 
could run at a megabaud, turning a QD 3.5" drive into a 2.88 megabyte 
drive. Floppys are essentially extinct since drivewire is nearly as 
fast, and for nitros9 systems, there is no real size limit, I've a 105 
megabyte floppy image that DW has no problems with, it just works. I 
haven't tested but using a cluster size some power of 2 greater than the 
default 1, could allow a "floppy" image in the 4 gigabyte area.

Installing this "better address decoder" in the coco3 would not be for 
the faint of heart as it would be a bit invasive with the trace cutting 
and wire wrap wire for patches. But it could be done.

Several of you have already demonstrated that you ARE capable of such a 
thing.

So whats stopping one of you from making that your next big thing?

Cheers, Gene Heskett
-- 
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