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SD to DD disk image

G

giobbi

Veteran Member
Joined
Dec 23, 2012
Messages
987
Location
São Paulo country, Brazil
...it seems (to me) that it's easier to find a PC floppy drive that works with Image Disk and DD disk images. I can make floppy from any DD image, but not from SD images.

Is it possible to convert an SD .imd image into a DD .imd image? If yes, is there any software available for it?

There are some utils I wish to use on my DD Osborne, but I can't transfer the disk images to floppy because of my IBM XT floppy drive limit....

cheers,
Giovi
 
I needed to write SD (assuming that means Single Density) images for my TRS-80 Model I.

The disk controller on my PC with 360k drives didn't support that. So, I built one of these:

http://www.malinov.com/Home/sergeys-projects/isa-fdc-and-uart

It wasn't hard, or expensive, and it works great!

Otherwise, you need to use an Emulator to copy files from an SD image to a DD image that you can write with Imagedisk.
 
Let's see if I can follow what you're asking.

You have some single-density (FM) O1 disks and you want to transfer the files to a double-density (MFM) disks. Do I have that right?

First off, you can't do a sector for sector transfer, because there is the matter of the *logical* disk format--that is, the size of an extent, the number of sectors per allocation block, the number of allocation blocks in an extent, etc. In addition, the directory will probably be in a different place and different size between the FM and MFM images. Your O1 in DD mode will expect to find things where the DD disk parameter block says that they are. You could (laboriously) create an image having everything re-configured, but it'd be a lot of work.

The normal 5160 disk controller, if it's the original IBM, doesn't do FM. However, many later PCs, such as the P2 and P3 models do, using the onboard floppy controller. If you have any later systems, you might want to see if they support FM. You could also swap the 5160 controller for a different one with FM support.

If you just need to extract the files from an FM IMD, point me at the files, and I'll do that for you. You can then use something like 22DISK to create your O1 DD floppies.
 
Chuck(G) said:
Let's see if I can follow what you're asking.

You have some single-density (FM) O1 disks and you want to transfer the files to a double-density (MFM) disks. Do I have that right?
Click to expand...

Sorry, I didn't explain correctly my needs.

What I need is to convert the SD disk image (.imd files) into DD disk image. I can make a DD floppy from a DD disk image, but I can't make a SD floppy from a SD disk image.

I downloaded some disk images for Osborne, but most of them are SD so I can't use them because my IBM XT can't write SD. It write DD disks from DD disk images flawless, but nothing to do with SD images.

...and the only other PC with a 5.25" - 1.2 Mb disk I have can't write neither SD, nor DD disks :-(
 
giobbi said:
Sorry, I didn't explain correctly my needs.

What I need is to convert the SD disk image (.imd files) into DD disk image. I can make a DD floppy from a DD disk image, but I can't make a SD floppy from a SD disk image.

I downloaded some disk images for Osborne, but most of them are SD so I can't use them because my IBM XT can't write SD. It write DD disks from DD disk images flawless, but nothing to do with SD images.(
Click to expand...

Okay, as long as we're just talking about files (not boot tracks), I think we can do this. If you can write DD images, you can run 22DISK to format and write from DOS to CP/M, right? So, if you can tell me where to find the SD images, I can extract the files from them and you can take those and create your own DD Osborne floppies. PM me with the images if you want.
 
Chuck(G) said:
Okay, as long as we're just talking about files (not boot tracks), I think we can do this. If you can write DD images, you can run 22DISK to format and write from DOS to CP/M, right? So, if you can tell me where to find the SD images, I can extract the files from them and you can take those and create your own DD Osborne floppies. PM me with the images if you want.
Click to expand...

well, here: http://www.retroarchive.org/maslin/disks/osborne/index.html there are some SD images I wish to check (expecially the utils images and 80 cols mod). But, since there are many files and I don't know exactly what of them I will need, maybe you would explain me how to extract files from the images, admitting it can be done with some software under DOS or Windows...

I'm going to check if 22disk will work on my environement...

--Giovi

EDIT ----
ok, it seems I can format and write data from DOS to CP/M disks.
 
Last edited:
It's my own software--not ready for prime-time, but it works well with Osborne images. PM me with your email address and the exact images that you want and I'll zip the files up for you.
 
Chuck(G) said:
It's my own software--not ready for prime-time, but it works well with Osborne images. PM me with your email address and the exact images that you want and I'll zip the files up for you.
Click to expand...

ok Chuck, thank you! I will see what I need exactly and I will tell you soon. I'm searching the utilities disk for the Rombo add-on card...
 
Chuck,

I wish to know if you can extract for me the following disks. Since I don't know if yours is a "one-click-does-all" software or it is quite a huge amount of work for every disk image, I will list here some images: the first listed are the ones I will probably need more than the others. I'm saying "probably" because I'm not completely sure about the content. Don't waste too much of your time for it: If you think I'm abusing of your patience, please let me know and feel free to process only what you want/can...

URL: http://www.retroarchive.org/maslin/disks/osborne/index.html

images:

os1utls.td0 55960 SSSD Osborne 1 utilities disk
os1xutls.td0 35382 SSSD Osborne 1 extended utilities
os1dias.td0 46760 SSSD Osborne 1 diagnostics disk
os1mcal.td0 40392 SSSD Osborne 1 communications disk

Not needed, really: out of curiosity only, since I programmed in dBase in the past century ;-)
os1dbase.td0 56706 SSSD dBase II program disk

thank you!
Giovi
 
I'll see what I can do. Interesting that they're still using TeleDisk for their images over there--I'dve through that IMD was the preferred platform.
 
Chuck(G) said:
... Interesting that they're still using TeleDisk for their images over there--I'dve through that IMD was the preferred platform.
Click to expand...

That's the Maslin archive, which, if I remember correctly, predates the ImageDisk effort (mid 90's for the Maslin archive as I recall). They're all in teledisk format.
 
Chuck, thank you, it worked.

The worst part was to find some reliable floppy disks among the many I have; it seems I have only 10% working left...
If only there was a reliable source at honest price for new, 5.25" floppy disks...
 
Humidity can be a real problem with floppy disks. Being in Sao Paulo, you probably have run into this problem. Do you have access to a food dehydrator? Try "baking" some of the bad ones at 58C for an hour or two and see if things improve. Also, keep the heads on your floppy drives clean--a failing disk will often leave deposits on the heads that will interfere with subsequent attempts to read or write.
 
Chuck(G) said:
Humidity can be a real problem with floppy disks. Being in Sao Paulo, you probably have run into this problem.
Click to expand...

We'll, humidity WAS the problem, indeed. Not because of living in Brazil (here the weather is quite dry and with a low humidity %) but because I found the floppies in the house fundament when I bought it... I guess some of the mushrooms that are grown over their surface would be a good ingredient for japanese food ;-)

Chuck(G) said:
Do you have access to a food dehydrator? Try "baking" some of the bad ones at 58C for an hour or two and see if things improve.
Click to expand...

I haven't :-(

Chuck(G) said:
Also, keep the heads on your floppy drives clean--a failing disk will often leave deposits on the heads that will interfere with subsequent attempts to read or write.
Click to expand...

yep, I already discovered that. Actually, every time I find a bad floppy I immediately clean the headers with alchool. This method is giving the best results, avoiding to damage more floppies.
 
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