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Osborne 1 disc problem

P

Primo007

Member
Joined
Apr 15, 2022
Messages
19
Location
Portland OR
Hello!

I've been working on an Osborne 1 I found and have gotten it to the point where everything powers on and displays the "please insert disc" prompt. The only thing is that the drives spin up, and the little red light goes on, but neither stop. Would this be an issue with the belts? If so where would I find replacements?

Thanks!
 
More than likely you have a floppy that doesn't boot (bad Media), or the floppy drive needs the head
cleaned (old brown oxide deposit on the head). You are lucky that the Osborne can also boot
from B: drive to allow testing the same Floppy's booting on the second drive. I do not know the
proper keystrokes to do that, but have read about them on some VCF posting.

Larry
 
Probably not the belts as they are fibre not rubber in all probability.

Does it eventually give an error message scrolling up the screen ?

To be honest, a Gotek is what I would fit as it makes using this machine easy (but needs an adapter to fit)
 
So would I be able to put a non-boot disc in to test, or would that just give me the dame error?

Also, do I clean the heads with just some isopropyl alcohol and q-tips?
 
If it is a non-boot disk about all that would prove would be that you've successfully failed to boot from drive b: --- a boot disk is necessary to boot. Unless you have a 5 1/4" cleaning disk, or make one, you can clean the head(s) with q-tips and DNA or IPA. But don't bend the head assembly trying to get at the heads.
Click to expand...
 
If its trying to read the disk and can't, it should give an error

If its waiting for the head to step to track 0 or can't see the index pulse, I think it just sits with the light on.

So, is the head stepping to track 0 ?, you might have to manually shift it from 0 with the power off the check. Does it have the double density adapter and is it mounted correctly (they are upside down, and often fall off, its a simple matter of refitting and heating the gum up on the mounts to restick it)
 
I'd try booting from A:, then next try booting from B:, after carefully and slowly moving the head
carriage assembly to the center position of travel. Then when you try A: or B: you should
hear the stepping to Track 0. My Radio Shack TRS-80 Model 4, sometimes doesn't step and I
have to gently reposition it and then it's good until the next time it doesn't step. (I've cleaned
the Tandon TM-100 Drive rials, and lubed them with Dri-Slide, a Motorcycle Cable Lubricant.)

If it doesn't boot the floppy, but does move to Track 0, then Clean the heads, and try another Boot Floppy.
Hopefully you have another boot floppy properly marked, so you know it works.

Do you know if your Osborne has Double Density or is it Single Density?

If you use Debian Linux, you can create a bootable floppy from Debian. Debian still supports CP/M Floppy's.
Here is how I write TRS-80 Floppy's using Debian.

https://forums.debian.net/viewtopic.php?f=16&t=151313

Code: 
# Osborne 1 - SSSD 48 tpi 5.25"

"OSB100":
 SS SD sect=10 dtr=1 fm=1 ssize=256

# Osborne 1 - SSDD 48 tpi 5.25"

"OSB200":
 SS DD sect=5 ssize=1KB

# Osborne Executive - SSDD 48 tpi 5.25"

"OSB200":
 SS DD sect=5 ssize=1KB

# Osborne 1 + Osmosis - DSDD 96 tpi 5.25"

"OSB400":
 DS DD sect=10

# Osborne Vixen - DSDD 48 tpi 5.25"

"OSB400":
 DS DD sect=5 ssize=1KB

# Osborne Executive w/Z3 - DSDD 96 tpi 5.25"

"OSB800":
 DS QD sect=5 ssize=1KB

Or, if you have a DOS Computer, I can assist you in creating a replacement Boot Floppy.

Larry
 
Thanks for all of the help everybody! I'll hopefully get some time later today to try some of these and I'll post here how it goes!
 
So, turns out that it was just that I used the wrong disc when I first tried to boot it (at the time it was the only disc I had for it and it said not on it, though this was for booting an external hard disc and not the actual osborne). There is one thing that I found when I was able to stay using it though. A few characters of text were cut off from most programs and the whole screen was off center. Is this something to do with the CRT itself or maybe something weird with the firmware? 20220725_164353.jpg
 
I dont think there is anything wrong with your screen (apart from the brightness being too high, you should not be seeing the flyback lines), I think its the setup of this disk.

As the Osborne uses an 'interesting' video memory scheme, this can happen. The screen can be though of as a small view into a larger view. You can scroll around this larger view with the arrow keys. Press CTRL & Right arrow and see if the missing words come into view.

Program disks can be setup to boot with certain screen parameters using the SETUP.COM program. This should be on the disk your using. Run this and you should get the Configuration program where you can choose the screen size. I think you need to make sure its set as 128 but its, as I remember, slightly counter intuitive (well for me anyway) so also try 52. While the 'actual' screen size won't change, it informs the program what the screen size is and should make it work correctly.

The Osborne 1 users reference guide describes this on page 10 and the adjustment of the system 'screen size' on page 40.
 
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