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OS for Model III

I dug around and found a DSK image of LDOS, but could find no converter that would allow me to use TeleDisk or Imagedisk to write out the image. I found a DMK image of LDOS 5.3.1a and successfully used DMK2IMD to create an image I could write out using my 5160.

Is there a utility out there that will convert DSK images to DMK? What about a tool that would run on a 5160 that would write DSK images?

Is there a reason to choose ImageDisk over TeleDisk for creating images?

tnx!

g.
 
I went to the Misosys website, downloaded LDOS and LSDOS for the Model III and 4.

Then, I downloaded SDLTRS and used it to mount the JV3 .DSK images. I made blank DMK images in SDLTRS, formatted the blank, and then backed up the .DSK image in :0 to the DMK image in :1.

I took those DMK images and used DMK2IMD to make them Imagedisk images.

I was then able to take them to my 5150 and write them out using Imagedisk.

They both booted fine on my Model 4D.

If you have a 386DX computer, you can use one of the MSDOS based emulators to write the disks directly to a 5.25" drive from the DSK images.
 
geneb said:
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Is there a utility out there that will convert DSK images to DMK? What about a tool that would run on a 5160 that would write DSK images?
Click to expand...

Tim Mann's cw2dmk utilities includes utilities to convert to and from JV3 formatted DSK's. The jv2dmk program is the one you want. You don't have to have a Catweasel to use it. There is, however, some question as to whether you need a 386 at minimum to run them, as they are compiled with djgpp and use a DPMI host for extended memory support. So it won't run on a 5160. But, it is open source, so you could have a try at porting it to a different DOS compiler.


Is there a reason to choose ImageDisk over TeleDisk for creating images?
Click to expand...

Yes. ImageDisk is an open and fully documented format, and td0 is not.
 
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Thanks lowen - I'll check out the jv2dmk program. I download images to my windows machine first, so that would be able to handle running the jv2dmk program - even if I need to use dosbox. I then send the files to a Linux host and then download them to the PC using zmodem. :)

Good point on using ImageDisk. I keep forgetting about that.

Al, that's a really convoluted trip to get from point A to point B. It'd be like me wanting to go from Seattle to Los Angeles by stopping at New York, London, Amsterdam and Sydney on the way. :D

thanks all!

g.
 
Mot in the least Gene. It was a very straight-forward way given the limitations I had at the time.

Now that I spent the money to build a dedicated Emulation box, I can create disks driectly from the various DOS-Based Emulators. I didn't have that ability two weeks ago.

I'm interested in getting results. And, doing it the way I did caused me to learn a lot about LDOS/LS-DOS and Montezuma Micro CP/M.
 
Ahh, good point! I'll have to make a note of that.

Right now the issue I'm having is ImageDisk does NOT like any of the old disks I'm feeding it. It complains about "No Data", etc. on every single track. This happens on disks that boot perfectly fine on the real hardware, so I'm not quite sure what's going on. I'm wondering if the IBM drive controller in the XT isn't up to the task of reading those disks - maybe they're all single density or something? I've got it configured for single sided, 40 tracks.

g.
 
The Floppy Controller in the IBM XT 5160 doesn't support Single-Density, I believe only the very early controllers in the 5150 supported single-density.
 
That's likely my problem then. I'll run testfdc on another controller I have and see how that goes.

Is there any issues with writing low density disks in high density drives? I suspect reading the media in an HD drive is fine, but I have a fuzzy memory about there being an issue with writing. I don't want to have to change out drives if I can avoid it.

tnx.

g.
 
geneb said:
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Is there any issues with writing low density disks in high density drives? I suspect reading the media in an HD drive is fine, but I have a fuzzy memory about there being an issue with writing. I don't want to have to change out drives if I can avoid it.
Click to expand...

Chuck's the expert on that, but it boils down to track width. The high-density drive (1.2MB 5.25) is a 96 tracks-per-inch drive, and a standard 40-track drive (either for single-density or double-density; on the PC a standard 360KB is double-sided and double-density) is 48 tracks per inch. If you properly degauss the disks before writing them with the HD drive the narrow track should be ok, and should read fine on the wider track drive. However, if there is data left on the disk, it will end up 'between the tracks' since the HD drive is going to double-step for 40 track mode, and since the head is half the width; a real 48 TPI drive reading this disk will see both the narrow track laid down by the HD drive's head and the data that was already there and it will get mixed in the head.

Also, be sure you are using double-density rated media; the HD drive is going to change its heads' magnetic characteristic depending upon which density mode you're in, and HD media may not be reliable when recorded with the heads set for double-density (or single-density, either) mode.

Now, since the wider head in a 360KB DD (48 TPI) drive is writing essentially a double-width track from the point of view of the HD drive, reading 48TPI media in the 96TPI HD drive typically works just fine.

For more details, see http://retrotechnology.com/herbs_stuff/drive.html
 
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The disks I'm using are NOS SSDD & DSDD disks, so if it comes to it, they may be ok. I'll certainly know if the Model III won't boot one. :)

Thanks.

g.
 
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