3.5" floppy disk revisited on the UNIX pc ...

[Lenny Tropiano]

In article <115 at pbhacker.UUCP> tlh at pbhacker.UUCP (PUT YOUR NAME HERE) writes:
|>In article <695 at icus.islp.ny.us> lenny at icus.islp.ny.us (Lenny Tropiano) 
writes:
|>>Now how did we manage to get both drives on the UNIX pc at once, since the
|>>hardware only supports one ...  Well it's sorta a hack, but basically it's
|>>a mechanical switch (SPDT) that switches the FDRIVE0* signal (pin 10) between
|>>the 5.25" drive (360K) and the 3.5" drive (720K).
|>
|>Instead of using a mechanical switch, why not change the system's device
|>drivers to make use of the 4th LED as a switch.  You would still only be able
|>to access one drive at a time, but you could do it remotely and not have to
|>manually flip a switch.  Here's how it might be done.. if the 5 1/4 drive
|>device file is accessed, the disk device driver would turn "off" the fourth
|>LED and (with some minor main-board modifications) this would cause a physical
|>connection to be made with the 5 1/4 drive.  If the 3.5 device file is 
|>accessed, the exact opposite would occur.  comments?
|>

Sounds intriguing, but seems to me to be overkill.  Making the changes in the
wire (ribbon cable) to change the FDRIVE0* signal (pin 10) was pretty simple.
No hacking on the motherboard.  The drawback on your method is that it
would require you to load a device driver to use the 3.5" floppy drive.  This
means if you want to use it from the Floppy UNIX, it becomes kinda hard without
all the pieces for loading device drivers ... (yeah you could mess around
with mounting the hard disk and loading the device, but that's more hassle
than it's worth -- it's something I messed around with trying to load the
"Cartridge Tape Driver" from the floppy, to restore an entire "/" backup).

I'm not shooting your idea down completely.  I sorta like the idea of not
having to worry which direction the switch is in, when I want to access
a floppy, but for the amount of time you actually use the floppy, I'll
just do it my way...

Thanks for the ideas ... keep 'em rolling in (on all topics)...

-Lenny
-- 
Lenny Tropiano             ICUS Software Systems         [w] +1 (516) 582-5525
lenny at icus.islp.ny.us      Telex; 154232428 ICUS         [h] +1 (516) 968-8576
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