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Re: Commodore drives can be controlled on Apple II serial!
Rubywand <rubywand@swbell.net> writes:
> If, as you say later, the C64 drives can be run from a PC COM port,
>there should be no problem running the drive from a GS serial port.
>Given information about which signals and codes the C64 drive needs, an
>interface routine could be probably be written.
It's not the COM port, but the LPT port. What you would need to do is
program the GS with some support for the IEC serial bus protocol. I don't
know how accurate the timers are in GS/OS (whether it steals clocks like
a certain Intel-based GUI which shall remain nameless), so it might have to
be done on the command line (Nathan could probably answer this question).
The IEC protocol is ridiculously timing-sensitive.
> That is not altogether clear. C64 disk I/O is not especially
>speedy. I just transferred a 178k file to our GS (PC HyperTerm to GS
>Spectrum) at 56k baud. The transfer took about 35 seconds. Based upon
>memories of long waits for C64 program loads, I'm pretty sure the C64
>drive connected to a GS could not do much better.
It probably wouldn't. After all, the most popular peripherals after disk
drives have been fastloader modules and Kernal upgrades for faster disk
access. :-)
1571s were capable of fast serial communications using a special mode called
'burst' mode, however, and could communicate with the 128 at a much quicker
rate than in 64 mode. So it might not be as slow as you might think.
> Another consideration is file size. Many .SHK files and Jpegs are
>too large for 5.25" diskette. (Some are too large for 3.5" diskette.)
>Transfer via diskette would be pretty cumbersome for large files.
You could try the 1581, the Commodore 3.5" drive; it also has a Western
Digital controller and can read MFM, but they're comparatively uncommon.
I consider myself lucky to have one. The 1581 is also somewhat quicker
than its progenitors.
The source, btw, for the Star Commander, the PC program that allows
connection to 15x1 drives through the LPT port, is becoming available, so
that may clue potential GS programmers in.
--
Cameron Kaiser
cdkaiser at concentric dot net (it hasn't helped the spam yet though)
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