🚀 go-pugleaf

In article <142@sjuvax.UUCP> lyle@sjuvax.sju.edu.UUCP (Wayne J. Lyle) writes:
>
>	I would like to know if there exists a 3 1/2 disk
>drive and controller that would work on a standard IBM PC
>or Compatable?  I would like to be able to transfer files
>from a Desktop PC to a portable unit without having to
>connect them via the serial port.

Yep.  The standard floppy controller that comes with the IBM PC/XT series
will work just fine as a 3.5" controller.  Of course, you must have 3.5"
drives that use the same 34 pin connections and the 5.25" floppies, 
otherwise an adapter is needed.

The XT that I am using has two 20MB HDs, two 5.25" half-height floppies
and two 3.5" TEAC diskette drives.  For the older machines, PC-DOS 3.20
is needed.  It contains the device driver needed to format 720K diskettes.
You will need to make up a cable to use them externally or internally.
Externally they attach to the 37 pin connector.  Internally they attach
just like 5.25" floppies, but you will need a different connector for TEAC
style drives.  Again, you will have to get PC-DOS 3.20, unless you have the
new XT frame, ie, new keyboard and BIOS.

The new XT frame has built into the BIOS the means of checking for 3.5"
drives.  What the BIOS does is test all of the drives that are switched
for, ie, the number of drives selection switch (which in the old manuals
only shows two positions, but really has four possible positions in the
binary count).  It then maps into the system the drives that it does find
and what they are, ie, 360 or 720.  So, the new XTs do not need PC-DOS 3.20.

But, the new BIOS creates a problem.  If you set the number of drives to 4,
like we do here in engineering and you only have two attached, your hard
disk will become C.  If you later attach a third floppy, your hard drive
will become D.  Boy, can that mess up software, especially the AUTOEXEC.BAT
file, if it contains drive references in it.

MINOR FLAME

What inspired IBM to search for the floppies and change the number of drives
mapped into the system, from what was switched on the mother board?  Doing
such just makes in difficult to disconnect external drives and still be
able to run hard disk programs.  It also makes it difficult to plan for
the future, ie, set the switches for 4 drives and add #3 or 4 later,
without having to go back inside of the frame or change any software.

FLAME OFF

I just got off the phone with IBM Customer Relations and she is going to
look into this problem.  She thinks that doing what I described is ludicrous.
She is going to check from her end I am going to go through the dealer and
the IBM dealer support line to get an answer for a way around it.  I will
report back when I have an answer.
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