Disk imaging with IMD - question

rich.cini at verizon.net rich.cini at verizon.net
Wed Aug 9 13:13:49 CDT 2017

Mike -- 

I gave Bill Degnan the backstory in another thread but in short, I'm working on restoring VCF's Seattle Gazelle. It uses a DSDD drive system, although the original drives are still at Infoage. I have the original Seattle disks. The system was shelved in the mid-1990's. 

I have the system booting to the monitor (after performing all of the usual power supply work) but the main task is getting the disks imaged before getting everything booting using the original hardware. 

I have a PC/AT with an Adaptec HD/floppy card that per Dave should work for all density combinations. It indeed passes with a Teac 1.2Mb drive. 

So the plan is to connect an 8" drive to it and use it as an "imaging machine". So yes, to read and write 8" disks. 

The MSDOS part was just a simple way to test that the controller and drive worked as expected before working on original Seattle disks that aren't replaceable. There is MS Pascal, Norton Utilities, SCP-DOS and two versions of MSDOS (1.25 and 2.0). There are also some disks that may have code/sources on them. 


Sent from Verizon/AOL Mobile Mail

On Wednesday, August 9, 2017, Mike Stein via cctech <cctech at classiccmp.org> wrote:

----- Original Message ----- 
From: "Richard Cini via cctech" <cctech at classiccmp.org>
To: "Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
Sent: Tuesday, August 08, 2017 8:54 PM
Subject: Disk imaging with IMD - question

Guys –

I’m working on a restoration project for VCF that requires imaging 8” disks (both SSSD and DSDD, mostly for the Tarbell controller) but I’m having trouble with it reading disks. So, I wanted to run through what I’ve done and see if I’m missing anything. 

It took me a while to hunt down a controller that would work with the PC/AT I have on the bench and that would pass all of the testfdc tests. The floppy drives are both 1.2MB drives. I located an Adaptec AHA-1522F. Testfdc passes.

Next, I connected my 8” drive (a QumeTrak 242) to the controller using the 8” floppy interface adapter from DBit. On reboot, the BIOS seeks the drive no problem so I would say that the physical interface works. 

I tried formatting an 8” DSDD disk for MSDOS and I can’t get that to work (not sure why since the 8” drive should be similar to the 1.2MB). Rerunning the testfdc program fails all tests with the 8”, and it doesn’t successfully read any of the non-critical sample disks I have.

Not sure this is enough for someone to go on, but I thought I’d throw it out there. 

As a separate question, what kind of disk imaging setups are people using for 8” disks? 

Hi Rich,

I'm not clear on what you're trying to do; archive 8" disks on a PC, create 8" disks on a PC, or both? 

Where does MS-DOS format come in? What system uses a Tarbell controller to read/write MS-DOS disks?

Probably not relevant for you but since you asked, FWIW I use a Cromemco system to DD/TAR/FTAR 8" disks to a file and then either copy that to a PC over a serial connection or copy it to a 3.5" or 5.25" HD disk that both the Cromemco and the PC can read & write.




Rich Cini



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