Post by lkraemer » 2023-02-09 19:45
This HOWTO: explains how to use Debian 11 to write 5.25" SS/DD Boot Floppy's for a TRS-80 Model 1.
If you are not familiar with DOSBOX, refer to the following URL as DOSBOX is used to create the .RAW Image (Sector Dump)
viewtopic.php?f=16&t=61888
I had previously create a Preservation file on my OLD DOS Computer, named ND80-M1-ORIG.DSK.
My problem was that my OLD DOS computer was 1500 miles away, and I needed to make a couple boot floppy's. I located my
5.25" SS/DD Floppy Drive, and strapped it as DS1 in the DS{0..3} configuration. This matched my Desktop's Floppy cable which
had conductors 10 thru 16 twisted for the floppy at the end of the cable. I re-booted and set my BIOS for a 360K Floppy Drive in
A:. When I tried to access the floppy drive, I had no response from the drive. Finally, I remembered to check the /etc/mediaprm file
to locate the proper TRS-80 settings. TRS180 was the proper choice as the TRS-80 has 256 byte sectors, and 18 Sectors per
track for 40 Tracks = 184,320K. I used a Command Terminal to check, and set the drive Parameters.
/etc/mediaprm contained:
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"TRS180":
SS DD sect=18 ssize=256
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$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
fd0 2:0 1 4K 0 disk <------------------Proper Floppy Drive
sda 8:0 0 465.8G 0 disk
├─sda1 8:1 0 117.2G 0 part /
├─sda2 8:2 0 24.4G 0 part
├─sda3 8:3 0 321.7G 0 part
└─sda4 8:4 0 2.5G 0 part [SWAP]
$ sudo getfdprm /dev/fd0
get geometry parameters: No such device
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$ sudo setfdprm -p /dev/fd0 TRS180
$ sudo getfdprm /dev/fd0
SS DD sect=18 ssize=256
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
fd0 2:0 1 180K 0 disk <------------------- Correct size for Floppy
sda 8:0 0 465.8G 0 disk
├─sda1 8:1 0 117.2G 0 part /
├─sda2 8:2 0 24.4G 0 part
├─sda3 8:3 0 321.7G 0 part
└─sda4 8:4 0 2.5G 0 part [SWAP]
to be in the SDLTRS subdirectory. I used the following commands in a command terminal:
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$ cd ~/Downloads/SDLTRS/sdltrs-master/diskimages/
$ sudo ln -s /dev/fd0 disk1
$ sudo ln -s disk0 ~/Downloads/SDLTRS/sdltrs-master/diskimages/Newdos81/ND80-M1-ORIG.DSK
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lrwxrwxrwx 1 larry larry 66 Jan 27 09:25 disk0 -> /home/larry/Downloads/SDLTRS/sdltrs-master/diskimages/Newdos81/ND80-M1-ORIG.DSK
lrwxrwxrwx 1 larry larry 66 Jan 27 09:25 disk1 -> /dev/fd0
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sudo sdltrs -model 1 -romfile level2.rom -disk1 /dev/fd0
PDrive :0
Which is telling me Drive 1 has the same parameters as Drive 0. I can just use the copy0* TI=A,TD=A,TC=40,SPT=10,TSR=3,GPL=2,DDSL=17,DDGA=2
1* TI=A,TD=A,TC=40,SPT=10,TSR=3,GPL=2,DDSL=17,DDGA=2
2* TI=A,TD=A,TC=40,SPT=10,TSR=3,GPL=2,DDSL=17,DDGA=2
3* TI=A,TD=A,TC=40,SPT=10,TSR=3,GPL=2,DDSL=17,DDGA=2
4* TI=C,TD=E,TC=40,SPT=18,TSR=3,GPL=2,DDSL=17,DDGA=2
5* TI=C,TD=G,TC=40,SPT=36,TSR=3,GPL=2,DDSL=17,DDGA=4
6* TI=A,TD=C,TC=40,SPT=10,TSR=3,GPL=2,DDSL=17,DDGA=2
7* TI=A,TD=C,TC=40,SPT=20,TSR=3,GPL=2,DDSL=17,DDGA=2
8* TI=A,TD=C,TC=80,SPT=20,TSR=3,GPL=2,DDSL=17,DDGA=2
9* TI=CM,TD=E,TC=40,SPT=18,TSR=3,GPL=6,DDSL=17,DDGA=2
command as it has format built into the copy command. If you have access to a Model 3
or Model 4 running Newdos 80, you can boot the Model 3 in Newdos 80 and change the
PDRIVE setting for :1 to a Model 1's floppy settings and create a Boot Image for the Model 1
by using the Model 3. The PDRIVE command allows all kinds of settings to be used.
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copy :0 :1
To verify that it will boot properly, I just need to change my symbolic links.
I delete the current symbolic links.
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$ sudo rm disk1
$ sudo rm disk0
$ sudo ln -s /dev/fd0 disk0
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$ sudo sdltrs -model 1 -romfile level2.rom -disk0 /dev/fd0
Larry