HP-85 Floppy Disk Images

[Gerry Schultz]

Hi, I'm in a bit of a dilemma and I hope someone has a solution. I'm working on my HP-85A and developing a source of software for it. I have an HP92901M 5 1/4" floppy drives and just connected an HP 9121 3.5" floppy drives to it through HPIB.

As a side note: It took me a while to figure out how to address the drives from the 85. The MSUS is in the form ":DXYZ" Where X is the address of the HPIB I/F plugged into the 85 (it's address is set to the default '7'), Y is the address of the disk chassis (the 92901M has address '000' and the 9121 has address '001') and Z is the ID for the drives in the chassis (0 or 1). So, in my case, the MSUS for 92901M drives are :D700 and :D701. The MSUS for the 9121 drives are :D710 and :D711. This is explained in the Mass Storage ROM Manual. I was pulling my hair out over this until I read the right manual.

Anyway, the HP Computer Museum has images of the 80 series stored as a Teledisk image file format type .TD0. I also have an HP Vectra 33N with a 3.5" drive running DOS 6.22. I have been using this setup to make software disks for my HP Portable Plus and 9114 drives.

Another side note: I'm also working on getting the PIL-Box to work with the Portable Plus. ILPer version 1.43 (?) doesn't work for me under Win 7 on my HP laptop. But it does work on my Dell XP machine. I'm working with J-F.

The problem is that the HP 85 disk images are 5.25 images and when I try to write the image to a 3.5" disk it fails. The destination disk has to be the same geometry as the image. Now, according to my reading, the 9121 is a 3.5" version of the 5 1/4" 92901 drives. They both store 270k worth of data and use the same file format. The only exception is that the 9121 is SSDD and the 92901 is DSSD drives and this is what's killing me. I don't have and the Vectra doesn't support 5 1/4" floppy drives.

So here are my questions. First, is there any way to make Teledisk write 5 1/4" disk images to 3.5" drives? Second, are there 3.5" Teledisk disk images that I can obtain? Trying to find a way to obtain HP-85 software is a royal pain.

Thank you for your assistance.

Gerry