Or, to put it another way: if I'm looking to add an HP-1B diskette drive for occasional use with an HP-85 or 87 (yes, I got the 85, and will be posting on it shortly), should I lean towards 3.5" or 5.25" disks?

Storage capacity isn't really an issue; this is just a toy. It seems to me as though the 5.25" drives might be more reliable long term since they lack the complex arrangement of articulating arms that mount and dismount the smaller 3.5" diskettes. 5.25" disks (and they look like Shugarts): they just have that simple lever-operated clamp.

Also, should I ever find a CP/M disk for my Auxiliary Processor module, it would be on 5.25" media, I believe.

Any other reason to choose one drive over the other?

3.5" floppies are easier to store and less fragile than 5.25". The drives take up less space too. On the other hand, if you want to play with the CP/M coprocessor for the 85, the dual 5.25" floppy is mandatory.

Regards,
Howard

Well, I have the coprocessor, but wonder what my chances are of finding an original, HP-specific CP/M disk...

Then maybe I could run WordStar!

PC with HP-IB (ISA or PCI) interface card plus HPDrive software which emulates various disk drives. But with this setup you cannot read real floppy disks. I use it with my HP-85/86/9816/9845B.

Good suggestion, but my real PCs aren't physically near the old HPs. Also, finding a motherboard that has anything other than PCI-E slots might be hard for me. I love the old stuff, but stay relentlessly updated on my real computers.

No problem, http://www.hpmuseum.net has it all. Use the search field on the home page and enter CP/M. If you have the setup as I described in my other post, you can easily convert the Teledisk image to a LIF image, and HPDrive will read it ...

Then I would buy a 9121. With my old PC I can write DS/DD 3.5" floppy disks so if you are in need of a CP/M system disk I can create one for you. On eBay you can still buy new DS/DD 3.5" floppy disks for some bucks.

Quote:

---

Also, finding a motherboard that has anything other than PCI-E slots might be hard for me

---

I have an old Gateway pentium mother board I'd be glad to donate.

And, per Juergen Keller's

Quote:

---

On eBay you can still buy new DS/DD 3.5" floppy disks for some bucks.

---

I also have a few DS/DD floppies I'd be glad to send anybody who wants them (they may even come with (useless?) programs on them from 15-20 years ago!).

Can you actually boot CP/M from a 9121?

Quote:

---

Can you actually boot CP/M from a 9121?

---

More to the point, does the Aux Processor card require a special version of CP/M?

Heck, maybe I should get both drives...

I don't currently have an 85 or an 82901, but I still have the coprocessor. My fuzzy recollection is that the coprocessor wouldn't work with the 9121 for some reason. And I do think you need the specific version of CP/M for the coprocessor. I also seem to recall that the CP/M was limited in its ability to read and write data from outside the CP/M environment. For example, you couldn't get it to work with an RS232 card, meaning all that CP/M terminal and file transfer software was useless.

Despite all that, I had a collector's trophy feeling about actually getting that sucker to boot. :)

Regards,
Howard

Yes, a special version of CP/M is required and available on hpmuseum.net. I successfully booted CP/M from my 9133 drive (which has a floppy and a hard disk drive). I do not have an 9121 device but I don't see an obvious reason why it shouldn't work with this drive, too. Please also note that the CP/M module requires an HP-86/87, it does not work with an HP-85 (due to the limited text display, CP/M requires 80x25).

Quote:

---

I also have a few DS/DD floppies I'd be glad to send anybody who wants them (they may even come with (useless?) programs on them from 15-20 years ago!).

---

Just DOS and Windows 3.1 stuff - no HP stuff.

Quote:

---

Please also note that the CP/M module requires an HP-86/87, it does not work with an HP-85 (due to the limited text display, CP/M requires 80x25).

---

Ah, that's right. Thanks for the correction. I ran it on my 87, which I also no longer have. :(

Regards

Howard

Quote:

---

Ah, that's right. Thanks for the correction. I ran it on my 87, which I also no longer have. :(

---

Get 'em here. Cheap! Well, relatively.

Did someone have some schematics or hardware documents about this coprocessor ?

It could be fun to add it to my fpga HP86/87
(see Site)

Olivier

Thanks for that link! I could seriously clutter up the apartment with gear from that site. :)

Regards,
Howard