Re: New idea HD for C=

From: Richard Atkinson (
Date: 1999-09-07 11:01:39

On Mon, 6 Sep 1999, Steve Judd wrote:

> > PS: Is it "a 1541" or "an 1541" ? :)
> "a 1541" :)

A 'fifteen forty-one' if you ask me. That's today's useful email for the

Regarding the SPEED-DOS parallel transfer cable with an IDE interface -
surely the CIA will power-on reset to all inputs for the I/O port, which
is high impedance. If a particular accelerated DOS happens to be
incompatible with the IDE attachment, then you can simply disconnect the
IDE devices, but I would certainly implement routines in the new disk
drive DOS to make interleaved IDE and C64 transfers if the computer
requested it. 3 out of 4 handshaking lines on the VIA are spare, so the
interface could be very fast.

Apparently filetype is one of the first bytes in the directory entry, and
there are 32 bytes altogether. This means that an extra type can easily be
added (there are a total of 128 filetypes possible, bit 7 being used to
indicate a file is closed). After the 16 bytes for the filename there are
15 left over, or 13 if the two spare bytes at the end are not to be used.
This should be plenty of space for other information (eg. start LBA
address, #tracks, #sectors) about the subdirectory, and if more is needed
the indirection pointing to the start of the 'file' can be used to store
254 bytes of information.

Does anyone know how a LOAD"$",8 is implemented? Is it handled (as far as
the computer is concerned) as a normal file called $ which the drive then
traps and sends back a special text file? Or does the computer send a
different kind of request...


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