HP 4145A Floppy Disk Duplication

HP's 4145A Semiconductor Analyzer boots from a 5.25" floppy, which isn't readily copied using modern hardware. This video shows how the 4145A's internal controller can be used outside the instrument to duplicate the boot disk.
Technical details, including source code for the firmware and the scripts, can be found here: www.kitsune-den...

[@RobertBaruch]

Actually, I don't think you can download the whole manual from Keysight. You can get the first part, the operation section, but not the second part, the service section, with the all-important schematics. Let's just say I plan on rectifying the situation.

[@jethrobo3581]

Wow! I spent an hour last night trying to figure out our "new" hp-4145a. We only have one floppy -- and after seeing this video, I think we're screwed! Oh well, this machine was free and the floppy it has is working OK (so far). Great video and thank you for the information!

[@MattNeighbour]

Bravo sir, bravo! Seriously impressive work.

[@MrTamhan]

Contratulations on keeping the unit alive!

[@alperenalperen2458]

Thats a lot of work. Congrats.

[@jwong19]

Nice approach, great achievement. It works!

[@peterdsdoyle]

Great video, I have the same unit however the disk is no longer readable, the drive is ok so I amy have a go at creating a new disk, do you think your image could function on my machine ?

[@TheMovieCreator]

Certain chipsets from the 90s are able to read and write the format, but only with special tools like Dave Dunfield's ImageDisk. If you got a machine with a compatible floppy controller, writing a new disk should not be too hard once you have a sectordata image. I used Notepad and HxD to get the binary 90KB sectordata image from the text-file published from this project. Then I used the HxC floppy disk emulator application to import this image as a "raw disk" (IBM FM, 250Kb/s, 1 head, 40 tracks, 9 sectors, 256B per sector), before immedately exporting it to the ImageDisk IMD format. Then all you need is to boot DOS on the compatible motherboard, and run ImageDisk to write the IMD to a blank disk. The image should contain the format metadata from HxC, so you don't need to care about every setting here. It's quite important to use a 48TPI 5.25" drive for writing, that works when set to a 360KB drive in the BIOS setup, and don't use a High Density disk.

[@thermionic_emission]

Awesome job!

[@onesupremelife]

Awesome Video! Thanks.

[@bluepainting5758]

Does anyone know how to read the exported DAT from the floppy? I have HP4156A and I can export to floppy but the DAT file is some kind of format I'm not familiar with....

[@elmariachi5133]

Yes, an Amiga with a 5,25" could have copied it. An C64 also, but maybe it would have needed custom firmwar for the floppy drive.

[@mnoxman]

Did you try and use a Linux/UNIX system and "dd" ?

[@kitsune-denshi]

Yes, as I said I tried on two PCs, both running Linux. The main issue is that the disk uses FM encoding, whereas PCs only every used MFM - so it's pure chance whether the controller would support it. Just trying computers until I found something that worked didn't seem like a terribly exciting prospect - no fun in that!

[@douro20]

It's ridiculous that they would use a disk format not compatible with anything else HP built.

[@2sc458]

Great video. I found this, that bolsters your description of the Floppy Drive architecture. www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1982-10.pdf

[@theannoyedmrfloyd3998]

You could put that disk image on a floppy emulator.

[@kitsune-denshi]

That is the hope for when the drive eventually gives up the ghost.