1.44M floppy on Color Computer (was Re: Ebay reaches new low)

From: Eric Smith <eric_at_brouhaha.com>
Date: Tue Nov 9 19:24:54 1999

Roger Merchberger <zmerch_at_30below.com> wrote:
> P.S. To keep this on-topic, does anyone have instructions on the hack to
> convert the above-mentioned floppy controller to be able to handle 3.5" HD
> floppy drives? I'd *love* to have a 1.44Meg floppy formatted under OS/9...
> :-) Also, is there any way (without reconstructing the 6 million dollar
> man...) to get two floppy controllers online using the MultiPak?

Even if you hack the FD controller's clock and data separator, it's possible
that the OS/9 floppy driver may not be able to handle the data rate of a
1440K floppy, which is 500 Kbps vs. the 250 Kbps of the drives it was
intended for. That's a byte every 16 microseconds, which is tricky
with no DMA or FIFO, since you have to poll for the FDC to be ready for
each byte.

I was disappointed to find that the optional floppy controller board
for the AIM-65 can support 8 inch double density operation (which has
the same data rate as the 1440K floppy) only with the addition of another
board with a DMA controller. Which, of course, I don't have. I'm not
sure that Rockwell even made it.
Received on Tue Nov 09 1999 - 19:24:54 GMT

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