TRS-80 Model 4 help requested

From: Al Hartman <alhartman_at_yahoo.com>
Date: Thu Feb 27 09:15:00 2003

> From: Patrick Finnegan <pat_at_purdueriots.com>
>
> Aparently, the Drive 0: is bad. Replacing it with
> the 1: or an IBM-branded Tandon drive from an IBM
> 5150 PC, it seems to try to boot from the disk. No
> disk in the drive (or the disk upside down) yields a
> "Diskette?" message on the display. A disk placed
> right-side up, which should be bootable, gives no
> messages on the display after power-up or reset.
> However, with a disk inserted, the drive light (and
> motor) turn> off after approx 7 seconds.

Ok..

Take a look at your "1:" drive. Near the connector you
should see a socket with something that looks kind of
like a chip in it.

But, it will have 4 metal bridges and three will be
broken. On your "0:" drive the first one will be in
place and 2 - 4 will be broken.

On the "1:" drive, the first, third and fourth should
be broken and the second bridged.

If you swap these between the two drives, you ought to
be able to turn the "1:" drive to a "0:" drive.

As for your IBM drive, it is probably jumpered for DS1
("1:" drive). If you can find the jumpers on the logic
board, move the jumper from DS1 to DS0 if you'd like
to try to use that as the "0:" drive (leaving the "1:"
drive as-is).

Let me know if that helps you.

> I tried using a boot disk that I got with the
> machine, and a fresh one from a .dsk file of LS-DOS
> 6.3.1H from Tim Mann's web site, using Tony's
> trsfmt and diskdmp. The image works with xtrs too,
> so I'm fairly confident that it should work when
> stuck on a floppy.

Sounds ok to me...
 
Regards,
Al
Received on Thu Feb 27 2003 - 09:15:00 GMT