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Burroughs B38

H

HomeLate

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Jan 8, 2024
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I have a Burroughs B38 system which is complete and fully working, including the original monitor, keyboard, and two modules — one containing a floppy drive and Seagate MFM hard drive, and a second separate hard drive module. The system boots and runs BTOS (Burroughs Task Operating System) from the original hard drive.

I have successfully imaged two hard drives associated with this system:

1. A working Seagate MFM hard drive containing a complete bootable BTOS installation in good condition. This is the drive the system currently boots from.

2. A second hard drive with bad sectors which the B38 cannot boot from anymore, but which I have able to image. This drive contained the full suite of BTOS software including COBOL and C compilers and associated libraries.

A larger hard drive in a separate module that does not currently spin up. Its contents are unknown but it may contain additional BTOS software or data.

Is there any interest to publish these disk images and where should I publish these?

Unfortunately the B38 is unable to boot from the most important, second hard drive. This drive worked initially and contained almost all software ever made for BTOS. Now the boot block contains errors and the B38 is unable to boot from the hard drive nor the disk image. I wonder if someone is able to recover the software or read the image to copy the software?

The images where made with the MFM hard disk emulator developed by David Gesswein.
 
HomeLate said:
Now the boot block contains errors and the B38 is unable to boot from the hard drive nor the disk image.
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Do you know if the boot block will be identical between the booting and non booting drive? There are ways with the emulator to copy the boot block from the one drive to the other. It it has lots of bad sectors that probably won't help.
 
I don't know but it is worth to try. Besides the boot block, the drive has a few bad sectors elsewhere on the drive.

The B38 tries to boot from the bad drive but fails and tries again and goes into a boot loop. The B38 behaves exactly the same with the MFM hard drive emulator and the image of the bad drive.
 
General approach is to use mfm_util to create an extracted data file (sector image) of both disks. Use your favorate program for manipulating binary files to copy the good block to the bad image. (I use dd). Then use ext2emu to create a new emulator file and see what happens when you try to boot it.
 
I have a B38, which is fully functional alongside my B28 (286). It sounds like you might be able to boot into CTOS via the floppy disk, then access the hard drive. I've just gone through and installed CTOS 12 off of the set of images on bitsavers, and needed to use the boot continuation floppy to bootstrap the system. I would love to get more NGEN software for my machines as I'm currently almost there, getting a cluster network going

I would be more than willing to give a try to get the images working on my B38 if your willing to share
 
Jaut_76 said:
I have a B38, which is fully functional alongside my B28 (286). It sounds like you might be able to boot into CTOS via the floppy disk, then access the hard drive. I've just gone through and installed CTOS 12 off of the set of images on bitsavers, and needed to use the boot continuation floppy to bootstrap the system. I would love to get more NGEN software for my machines as I'm currently almost there, getting a cluster network going

I would be more than willing to give a try to get the images working on my B38 if your willing to share
Click to expand...

The file is too big to attach here so I had to use Wetransfer: https://we.tl/t-iEXVkJqjCns8JCq7

In the zip file are 4 files: raw+emu of the working hard drive and raw+emu of the failed hard drive. All files were created with David Gessweins MFM emulator.

Good luck! Let me know if you get the image of the failed hard drive working or if you were able to extract any software from the drive image(s).

Everybody is free to get the files and experiment.
 
HomeLate said:
Good luck! Let me know if you get the image of the failed hard drive working or if you were able to extract any software from the drive image(s).
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I've downloaded them and will take a look tonight. I know that Bitsavers has a few copies of the Boot continuation disk for different CTOS versions that I'll try.

There is also a tool that can extract files from a CTOS file structure that was intended for floppies, but might work with these. I'll need time to learn it first.
 
Ive tried copying them onto my MFM emulator and didn't get much luck booting them. I'm confident it's my fault with something Linux-related. Also, my current CTOS install is broken as I mistakenly tried installing multiplan for an AWS on it, so I need to fully install it again.
 
firebirdta84 said:
But I'm most curious, how does the B38 differ from the B25? Does anyone know?
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The B38 shares the same IO and video cards as the B28 which is the 286 version. The B38 is a 386 and has 1mb or ram pre installed. The max can be 4mb with 3 1mb ram expansion modules.

As I’m sure you know the B25 is the original which is a 186. The B28 and B38 are fully backwards compatible both peripheral and software to the B25 but the problem is both run at a faster speed so some programs like Bugs run too fast to be playable.
 
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