Having a computer that can write and read tapes is great but, that left the problem of getting software on to the tapes.
The HP-85 doesn’t have a lot of I/O built-in but, it does have 4 expansion slots that can accommodate various adapters such as HP-IB (GP-IB), serial port, and a ROM tray for expansion ROMs.
The most popular technique for file transfer is to connect a disk drive to the HP-IB adapter. I also considered using the serial port but, I wasn’t sure that it would work.
So I needed HP-IB adapter. And, of course, to get a HP-IB adapter to work with a disk drive requires some expansion ROMs. Actually, if it had been an HP 85B instead of an HP 85, they would have been built in. It wasn’t though.
That meant I needed an HP-IB adapter, a ROM tray, and the various ROMs. None of this stuff is easy to come by. I did find a few vendors in the US with most of the items – unfortunately at high cost, high postage, and low interest in going to any trouble. This led me to the PRM-85. See my separate post on this.
I found a GPIB card in Australia on ebay, so I grabbed it.
There are not many computers that use HP-IB for their disk interface (the Commodore PET is one) so only an HP drive unit will do, and they are even rarer than DC100 tapes.
The HP computer community is awesome, though. Recognising that HP drives were becoming very rare, a chap from the HP 9845 project set about creating an emulator called HPDrive.
It runs on a PC with a GP-IB adapter installed, and it is particularly good. I followed the instructions at:
http://www.hp9845.net/9845/projects/hpdrive/
GP-IB cards are generally expensive but, fittingly for such a project, I found a reasonably priced National Instruments ISA card that seemed suitable (suitability is described in detail at the project site).
Then of course I needed a computer with an ISA slot. I had an old Windows 2000 machine stored in pieces that had a slot (I had some other older options as well) so I set that up with the downloaded disk images. I’m never short of a project.
And it just worked. To get the disk catalogue type:
CAT “:D700”
My notes were a bit sketchy about how i set this up so i recently fired it up again to gets some details. Unfortunately, part way through that exercise the PC motherboard developed a fault and i have not been able to resolve it. That means i will go through the exercise again sometime in the next couple of months!
