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Osborne 1 Single Density Boot Diskette

MicroCoreLabs

Experienced Member
Joined
Feb 12, 2016
Messages
273
Does anyone have a copy of a Osborne 1 Single Density Boot Diskette(s) they can send me? Im in California.
 
Standard video I believe. There are no other boards attached to the motherboard.

Thx
-Ted
 
Hi,
I was trying to help out by writing the SSSD boot image (O1SDSYS.IMD) so I could mail it over, but having some issues using ImageDisk to write the image on my DOS machine I had previously used for this purpose.
This is a PC running DOS 6.22, with a 1.44M drive as A: and a 360K drive as B:.
I have the system image from Dave Dunfield's site, and set up what I believe to be the right parameters for this image file, writing an SSSD image to a DSDD disk:
drive B, 40 cylinders, and double step off.
When attempting to write the disk, I'm getting tons of messages about write errors:
Write error <1> NoData
Write error <2> NoData
Write error <4> NoData
etc.

Tried several disks with no difference, and I can successfully DOS format these disks and write files to them without issue.
Has been a while since I've tried to write any disks on this machine so I'm not really sure what's wrong. Any ideas?
 
@bitfixer , My Osborne 1 had only the single-sided capacity drives, and I successfully used the disk image called o1cpms.imd (different filename to yours). As per my article, I ran Dave's TESTFDC utility first which tests your floppy disk controller at various speeds to see if your PC can cope with the format/speed you are attempting to write at:
testfdc.png

What were your results from TESTFDC?
 
Interesting, I ran the test and only the "double-density at 250 kbps" test passed, the other two failed.
Odd since I am pretty sure I've used this machine to write osborne SSSD disks before, although that was several years ago.
 
Another note - tried 2 more things. First, connected the 360k drive as the only drive (A:) and no change in results.
Also tried swapping with a 1.2M 5.25" drive and ran the test. Same results for low density media where only the DD 250 kbps test passes, and for HD media, only the DD 500 kbps test passed. Single density and DD / 128 byte sector tests failed.
Floppy controller is integrated on the MB. I may have some other floppy controllers I can try.
 
Yeah, I'm no expert (maybe reach out to Dave Dunfield since he developed those utilities), but it's the floppy disk controller chip that determines the ability here, so you're on the right track by disabling your onboard FDC via the BIOS and putting in something like a Goldstar Prime or Prime 2 FDC - I think that's what I used.
 
Thanks, I will give that a try. Just odd since I'm almost certain I wrote that disk with this machine before.. even found the actual disk I wrote.
 
You likely used a different controller. If you have a cooperating controller, writing and reading single-density (FM) is actually a bit easier (tolerates errors better) than double-density (MFM).
 
I was able to make my floppies from downloaded (TD0) files with a PIII machine and its onboard FDC, and Epson SD800 combo 1.44/1.2 disk drive. TeleDisk seemed to want to work and the O1 booted from the disks up to a point (logo) but then filled the screen with garbage and froze (reset button disabled?!? I guess it's not an NMI).
So I converted the TD0 to IMD, ImageDisk reported my FDC could to 250 and 300 in all modes. I found that writing with ImageDisk in 300 mode, Double-Step ON worked great

After that I used the O1 copy utility to write floppies with the native hardware to ensure compatibility
 
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