Postby lkraemer » 2022-01-24 07:30
UPDATED - 08/12/2022 for some typo's
This HOWTO: explains how to use Debian to write 5.25" Boot Floppy's for a TRS-80 Model 4's Diagnostics.
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 used IMAGEDISK Ver 1.18 by Dave Dunfield to create a Preservation file on my OLD DOS Computer. TRSDIAG2.IMD
My problem was that my OLD DOS computer was 1500 miles away, and I needed to make a couple floppy's. I located a 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. 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 settings. TRS180 was the proper choice. I used a Terminal
to check and set the drive Parameters.
/etc/mediaprm contained:
Code: Select all
"TRS180":
SS DD sect=18 ssize=256
$ getfdprm /dev/fd0NAME 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 setfdprm -p /dev/fd0 TRS180get geometry parameters: No such device
$ getfdprm /dev/fd0
$ lsblkSS DD sect=18 ssize=256
All that was left to do was to convert the TRSDIAG2.IMD file to a .RAW (Sector Dump) type file and write it to theNAME 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]
floppy with dd. I used the Imagedisk utilities (IMDA & IMDU) to create the .RAW file from within DOSBOX.
******************DOSBOX*******************
>mount c: ~/trs80gp/
>c: <enter>
>IMDA TRSDIAG2.IMD > TRSDIAG2.TXT
>IMDU TRSDIAG2.IMD TRSDIAG2.RAW /B /E /D >> TRSDIAG2.TXT
>z <enter>
>mount -u c
>exit
******************DOSBOX*******************
TRSDIAG2.TXT Contains:
Code: Select all
IMageDisk Analyzer 1.18 / Mar 12 2012
IMD 1.18: 23/01/2022 09:25:17
trs80gp blank disk 1 sides 40 tracks
Required cylinders: 40
Required heads : 1
Data rate : 250kbps
Est. maximum track: 6223 bytes
Possible drives/options to write TRSDIAG2.IMD :
5.25" DD 40-track
Double-step: OFF
5.25" QD 80-track
Double-step: ON
5.25" HD 80-track
Double-step: ON
250 kbps -> 300 kbps
3.5" DD 80-track NOTE: *1
Double-step: OFF
3.5" HD 80-track NOTE: *1
Double-step: OFF
*1 40 track image will use only first 1/2 of 80-track drive.
IMageDisk Utility 1.18 / Mar 07 2012
IMD 1.18: 23/01/2022 09:25:17
trs80gp blank disk 1 sides 40 tracks
Assuming 1:1 for Binary output
0/0 250 kbps DD 18x256
1 4 7 10 13 16 2 5 8 11 14 17 3 6 9 12 15 18
D D D D D D D D D D D D D D D D D D
1/0 D D D D D D D D D D D D D D D D D D
2/0 D D D D D D D D D D D D D D D D D D
3/0 D D D D D D D D D D D D D D D D D D
4/0 D D D D D D D D D D D D D D D D D D
5/0 D D D D D D D D D D D D D D D D D D
6/0 D D D D D D D D D D D D D D D D D D
7/0 D D D D D D D D D D D D D D D D D D
8/0 D D D D D D D D D D D D D D D D D D
9/0 D D D D D D D D D D D D D D D D D D
10/0 D D D D D D D D D D D D D D D D D D
11/0 D D D D D D D D D D D D D D D D D D
12/0 D D D D D D D D D D D D D D D D D D
13/0 D D D D D D D D D D D D D D D D D D
14/0 D D D D D D D D D D D D D D D D D D
15/0 D D D D D D D D D D D D D D D D D D
16/0 D D D D D D D D D D D D D D D D D D
17/0 D D D D D D D D D D D D D D D D D D
18/0 D D D D D D D D D D D D D D D D D D
19/0 D D D D D D D D D D D D D D D D D D
20/0 D D D D D D D D D D D D D D D D D D
21/0 D D D D D D D D D D D D D D D D D D
22/0 D D D D D D D D D D D D D D D D D D
23/0 D D D D D D D D D D D D D D D D D D
24/0 D D D D D D D D D D D D D D D D D D
25/0 D D D D D D D D D D D D D D D D D D
26/0 D D D D D D D D D D D D D D D D D D
27/0 D D D D D D D D D D D D D D D D D D
28/0 D D D D D D D D D D D D D D D D D D
29/0 D D D D D D D D D D D D D D D D D D
30/0 D D D D D D D D D D D D D D D D D D
31/0 D D D D D D D D D D D D D D D D D D
32/0 D D D D D D D D D D D D D D D D D D
33/0 D D D D D D D D D D D D D D D D D D
34/0 D D D D D D D D D D D D D D D D D D
35/0 D D D D D D D D D D D D D D D D D D
36/0 D D D D D D D D D D D D D D D D D D
37/0 D D D D D D D D D D D D D D D D D D
38/0 D D D D D D D D D D D D D D D D D D
39/0 D D D D D D D D D D D D D D D D D D
40 tracks(40/0), 720 sectors
If you have the SDLTRS Emulator installed on your computer you can use it to write the real floppy.
Skip to the SDLTRS section below.
******************TERMINAL*******************
Code: Select all
dd if=TRSDIAG2.RAW bs=256 of=/dev/fd0 conv=notrunc
The Floppy's booted when placed in a TRS-80 Model 4.
********************SDLTRS********************
SDLTRS is located at: https://gitlab.com/jengun/sdltrs
To use SDLTRS for writing the Floppy use the following command for startup. Use BACKUP :0 :1
to format and make a floppy from the TRSDIAG2.DMK file.
$ cd /path/to/sdltrs/
NOTE: the ROM images are in this path.
$ sdltrs -keystretch 400 -model 4 -romfile model4.rom -disk0 TRSDIAG2.DMK -disk1 /dev/fd0
********************SDLTRS********************
The floppy should boot on the Model 4.
Larry