EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Tandy on September 12, 2019, 07:15:08 pm
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I picked up a HP 4145A that has a 5.25" floppy drive with the system on it, a couple of things spring to mind...
I wonder if anyone else has one and what software version you have and if anyone knows what the most up-to-date version was? Mine is revision A05.
As the 4145A is pretty much the same machine, only with a 3.5" drive, it would be interesting to try the 4145B software on it.
Ultimately I think I would like to replace the drive completely with a floppy emulator for reliability.
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Not sure if the 4145B software will run on the 4145A: at least the disk format is different (LIF vs some proprietary format). However, it looks like this page contains instructions for setting up an emulator for the 4145A floppy drive on an mbed ARM Cortex M3 development board, and a disk image for use in that emulator: https://www.kitsune-denshi.net/equipment:hp4145a (https://www.kitsune-denshi.net/equipment:hp4145a)
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The 4145B, in addition to a different floppy disk drive, has more RAM than 4145A also.
Even if you can run 4145B software on 4145A you risk running out of memory.
However, the differences are seen comparing the two service manuals (probably with some modifications you can increase the ram).
A long time ago I post the firmware of my 4145A (all eproms) on the KO4BB website (www.ko4bb.com (http://www.ko4bb.com)).
But no one post the 4145B firmware so there is no way to know if there are differences here too.
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Thanks, I wonder if it really is a proprietary format on the 4145A or if Robert, who wrote that article wasn't familiar with LIF.
Anyway with the difference in memory it might not be worth the effort. I had hoped that it would be possible to essentially turn the 4145A into a 4145B by replacing the drive with a floppy emulator and using the 4145B software. Given the age of it, it is probably best just to use it as it is and be on the lookout for one of the newer models like the 4155B. But still an upgrade from my Tektronix 575 Curve Tracer that is really more of a museum piece than of any real use today.
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The 4145A uses a different sector format for its floppy disk from the 4145B, so there are will be differences in the firmware. No idea if they are compatible from a software point of view, but I see no reason for HP to have gone through the effort of maintaining compatibility.
Multiple sources, like this reddit post (https://www.reddit.com/r/electronics/comments/qdhaq/help_hey_does_anyone_here_know_how_to_extract/), mention that the 4145B is LIF, and 4145A is something else, so I'd say it's unlikely that the 4145A disk if LIF. Also this HP document (https://wiki.epfl.ch/carplat/documents/PDF/HP4155B.pdf) describes the 4145B as LIF, and 4145A as "unique".