help writing bootable Osborne disks from stream files

All questions about how to use KryoFlux go here.
KennyPowers
Posts: 14
Joined: Wed Jun 16, 2021 3:23 am

help writing bootable Osborne disks from stream files

Post by KennyPowers »

I have several old disks that are still bootable in my Osborne Executive. I've dumped them to raw, preservation stream files using the KryoFlux GUI. When I write them back to disks with dtc, I get the following error when trying to boot my Osborne from the written disk:

Image

It seems the computer is able to tell that the system files are there because it didn't throw the "not a system disk error". Also, if I boot from a known-bootable disk and put the written disk in drive B, I can read files and run programs from it...I just can't boot from it. I'm using a TEAC FD-55BR-578-U 360K drive to do all of the dumping and writing. The disks I'm trying to duplicate appear to be 40 track, MFM, five 1024B sectors per track. If I create a profile with those settings, I'm able to dump the disks to MFM sector images that are readable by cpmtools. I'm of course using the raw stream files when trying to write a bootable disk. I've tried degaussing the target disk before writing, but that didn't help. My ultimate goal is to be able to replicate these disks from their preservation stream files should I ever need to...what am I doing wrong?
ZrX
Posts: 658
Joined: Tue Dec 06, 2011 9:09 pm

Re: help writing bootable Osborne disks from stream files

Post by ZrX »

Try using the GUI to see how the scatter plot of a disk looks like.

You should see 3 very clear horizontal lines on the tracks. If there are noise between the lines it could be either a disk that has been written to or the dump is not very good and writing it back can be a hit or miss.

Interpreting the scatter plot somewhat requires one to know how differentiate between sectors and damage/noise.
KennyPowers
Posts: 14
Joined: Wed Jun 16, 2021 3:23 am

Re: help writing bootable Osborne disks from stream files

Post by KennyPowers »

ZrX wrote: Wed Jul 14, 2021 6:21 pm Try using the GUI to see how the scatter plot of a disk looks like.

You should see 3 very clear horizontal lines on the tracks. If there are noise between the lines it could be either a disk that has been written to or the dump is not very good and writing it back can be a hit or miss.

Interpreting the scatter plot somewhat requires one to know how differentiate between sectors and damage/noise.
I do see 3 distinct horizontal lines in each track's scatter plot. In the GUI, most tracks dumped orange 'H', but these are not original commercial disks, so that wasn't surprising to me. I do have the originals that came with the Osborne, but I wanted to get a reliable workflow down using less "important" disks first. When I dumped these, I chose multiple image types: "Kryoflux stream files, preservation" and a custom MFM sector image profile with the following options:

start track: 0
end track: 39
side mode: side 0
sector size: 1024 bytes
sector count: exactly 5
track distance: default
target RPM: default
flippy mode: unchecked
other params: none

I then write the stream files using a command like:

Code: Select all

dtc -f<path to first track's .raw file> -w -g0 -e39
Should I try dumping them in a different manner or different write options?

Update:
I dug out the original system disk that came with the system:
Image

It booted up fine. I then dumped it with the KryoFlux GUI as described above...all tracks showed green. I wrote the resulting stream files to a different disk...got a little further along in the boot process this time:
Image
ldkraemer
Posts: 25
Joined: Sat Apr 20, 2013 3:54 am

Re: help writing bootable Osborne disks from stream files

Post by ldkraemer »

From what I'm reading you want the .RAW files and a .IMG file. That was what I used years ago when I used my Brother's Kryoflux.

Your KryoFlux Board can read Floppy's and save the image as various formats. The INPUT File types are:

Code: Select all

Number Description Image Type
----------------------------------------------------------------------------------
0:......KryoFlux Stream Files - Preservation........RAW
0a:.....KryoFlux Stream Files - Format Guided....IMG
2:......CT Raw Image.......................................RAW
3:......FM Sector Image....................................IMG
3a:.....FM XFD, Atari 8-bit................................IMG
4:......MFM Sector Image.................................IMG
4a:.....MFM XFD, Atari 8-bit.............................IMG
5:......AmigaDOS Sector Image........................ADF
6:......CBM DOS Sector Image.........................D64
6a:.....CBM DOS Sector Image........................IMG
7:......Apple DOS 3.2 Sector Image...................IMG
8:......Apple DOS 3.3+ Sector Image.................IMG
8a:.....DSK, DOS 3.3 Interleave........................IMG
9:......Apple DOS 400K/800K Sector Image.......IMG
10:.....Emu Sector Image.................................IMG
11:.....Emu II Sector Image..............................IMG
12:.....Amiga DiskSpare Sector Image..............IMG
13:.....DEC RX01 Sector Image.......................IMG
14:.....DEC RX02 Sector Image.......................IMG
15:.....CBM MicroProse Sector Image..............IMG
16:.....CBM RapidLok Sector Image.................IMG
17:.....CBM Datsoft Sector Image....................IMG
18:.....CBM Vorpal Sector Image.....................IMG
19:.....CBM V-MAX! Sector Image...................IMG
20:.....CBM Teque Sector Image......................IMG
21:.....CBM TDP Sector Image........................IMG
22:.....CBM GCR Sector Image.......................IMG
22a:....CBM GCR Sector Image.......................IMG
23:.....CBM Big Five Sector Image...................IMG
24:.....CBM DOS Extended Sector Image.........IMG
25:.....CBM Ozisoft Sector Image....................IMG
So, you want types 0, and 4 as The Osborne Floppy's are MFM SS/DD or DS/DD 5.25" Floppy's.

I'm assuming you are using Floppy Drive 0 for this command and it is a 360K Floppy Drive.
Try this command to dump the .RAW stream and also the .IMG file.

Code: Select all

dtc -d0 -r5 -fOSB001/ -i0 -z3 -n+5 -fOSB001.img -i4 -l8 -s0 -e39
Let's see if that works.

If you just want to do the .RAW Stream files:

Code: Select all

dtc -d0 -r5 -fosb002/ -i0 -l8 -s0 -e39 
For an 80 Track Drive Reading a 40 Track Floppy use:

Code: Select all

dtc -d0 -r5 -fosb002/ -i0 -l8 -s0 -e39 -k2

How can I take the stream data from a proper dump and create an MFM image?

DTC -r <tries> -f<streamname> -i0 -f<sectorimagefrommfm.img> -i4 -m1
-m1 sets KF to "replay stream" data

The GUI (and Command Line) allows you to use stream files as input instead of Floppy Drive 0 or 1.

The command I use is:

Code: Select all

dtc -r5 -fMM001/ -i0 -fMM001.img -i4 -s0 -e39 -m1
And, if you download SAMdisk by Simon Owen, you can write the Image (.IMG) to Floppy (in Windows) with:

Code: Select all

SAMdisk MM001.img A:

LINUX:
If you have cpmtools built with libdsk, you can use the libdsk utility dsktrans to write the boot floppy from the .IMG (Sector Dump)

Code: Select all

dsktrans -itype raw -otype floppy OSB001.IMG /dev/fd0 

Larry
Last edited by ldkraemer on Wed Jul 14, 2021 10:05 pm, edited 8 times in total.
SomeGuy
Posts: 333
Joined: Wed Feb 18, 2015 8:18 pm

Re: help writing bootable Osborne disks from stream files

Post by SomeGuy »

First of all, what kind of drives are you using for this? You can't use an IBM PC style "1.2mb" (80 track 96tpi drive) to write a disks for use in a "360k/180k" 40 track 48tpi drive. (Technically, if you degauss the target disk first it should work, but that can be a headache)

Second of all, writing "raw" files back to disk is like making a photo copy of a photo copy. Your original might be readable, but if there is noise or minor damage on it, your copy might not be quite readable.

So what you need to do is decode the image to a minimum common denominator. ImageDisk format should work for Osborn disks, and then create a perfectly clean ".raw" flux stream dump that you should be able to write back to a disk. Unfortunatly the Kryoflux software does not support ImageDisk format, so third party tools such as the HxC software are needed.

But lets start by taking a look at the image you have read. Can you post the flux preservation stream dump you made of the disk somewhere so we can take a look at it and see if anything odd is going on here?
brightcaster
Posts: 432
Joined: Fri Nov 08, 2013 10:48 pm

Re: help writing bootable Osborne disks from stream files

Post by brightcaster »

You might try to write the attached raw-files and boot them. It's of a known good osborne executive boot floppy!

That should help to sort out whether reading or writing goes wrong...

The source is http://www.retroarchive.org/maslin/disk ... e-cpma.td0 converted to a raw stream. So this is not a copy from a copy, but (acording to SomeGuy) data brought down to the lowest possible denominator (TD0 file in this case) and after that converted to a perfect kryoflux stream (with no noise).

BTW: That's why the streamfiles are so small in size. It's only pure data in perfect alignment without any noise...

David
Attachments
OsborneBoot.zip
(319.1 KiB) Downloaded 7 times
ldkraemer
Posts: 25
Joined: Sat Apr 20, 2013 3:54 am

Re: help writing bootable Osborne disks from stream files

Post by ldkraemer »

David,
What was the dtc command for you to write the Streaming .RAW files? Was it similar to this:

Code: Select all

dtc -r5 -i4 -fOSB001.img -i0 /fOSB001/ -w -s0 -e39 -m1
If I already have the .IMG file (Sector Dump in a .RAW type file) is it necessary to write the streamed .RAW files?
What is the benefit?

Thanks.

Larry
brightcaster
Posts: 432
Joined: Fri Nov 08, 2013 10:48 pm

Re: help writing bootable Osborne disks from stream files

Post by brightcaster »

An .img file does include the raw data only but the .raw files include the raw (undecoded) flux changes! So don't mix up with raw data (.img) and raw flux (.raw).

dtc can't write .img files as there is no information about the geometry (sectors per track, number of tracks and sides etc.) neither is there any info about the coding (e.g. fm, mfm, gcr etc.) stored in an .img file. So you can only write .raw files with dtc.

A simple line like "dtc -f<path to first track's raw file> -w" with no other parameters should write a valid floppy if you use a 360k (48tpi) drive...

David
KennyPowers
Posts: 14
Joined: Wed Jun 16, 2021 3:23 am

Re: help writing bootable Osborne disks from stream files

Post by KennyPowers »

ldkraemer wrote: From what I'm reading you want the .RAW files and a .IMG file.
Well, yes, and I've been able to successfully create those I believe. Here's the command generated by the GUI from one of the log files...it looks very similar to yours, just with some extra stuff tacked-on by the GUI:

Code: Select all

dtc -l15 -f<path for raw files> -i0 -f<path for IMG file> -s0 -e39 -g0 -z3 -n+5 -i4 -r5 -d0 -p -e41 -dd0
I am able to open the resulting sector dump IMG file with cpmtools on Windows and see the contents of the disk.

What I'm wanting help with is being able to write one of these dumps back to an actual disk that will boot in my Osborne. So far, I've just tried writing the dumped RAW files back to a disk with the KryoFlux, which I understand won't be reliable.
ldkraemer wrote: And, if you download SAMdisk by Simon Owen, you can write the Image (.IMG) to Floppy (in Windows) with:
CODE: SELECT ALL

SAMdisk MM001.img A:

LINUX:
If you have cpmtools built with libdsk, you can use the libdsk utility dsktrans to write the boot floppy from the .IMG (Sector Dump)
CODE: SELECT ALL

dsktrans -itype raw -otype floppy OSB001.IMG /dev/fd0
Those options seem promising, but unfortunately I don't have a Windows or Linux machine with a 5.25" floppy drive. I was hoping to be able to write these dumped disks back to actual disks with the KryoFlux, but it can't natively write IMG sector dumps.
SomeGuy wrote: First of all, what kind of drives are you using for this?
A 40-track, 360K drive, model TEAC FD-55BR-578-U
SomeGuy wrote: So what you need to do is decode the image to a minimum common denominator. ImageDisk format should work for Osborn disks, and then create a perfectly clean ".raw" flux stream dump that you should be able to write back to a disk.
That sounds promising...can you give me more step-by-step instructions on how to do that? Like what intermediate file formats and software to use...preferably on Windows, though I can set up other environments if necessary.
brightcaster wrote: You might try to write the attached raw-files and boot them. It's of a known good osborne executive boot floppy!
Thanks! Trying that now and will report back...
KennyPowers
Posts: 14
Joined: Wed Jun 16, 2021 3:23 am

Re: help writing bootable Osborne disks from stream files

Post by KennyPowers »

KennyPowers wrote: Thu Jul 15, 2021 5:19 pm
brightcaster wrote: You might try to write the attached raw-files and boot them. It's of a known good osborne executive boot floppy!
Thanks! Trying that now and will report back...
I wrote those RAW files to 3 different disks and all of them did this when trying to boot from them:
Image

I then booted the Osborne from another disk, put the disk I wrote from those RAW files in drive B, and was able to run programs (SETUP.COM, etc) from the disk in drive B. I just can't seem to boot from any of the disks I'm writing.
Post Reply