Re: HP 4955A in Good Shape-- HPIB Interface for storing Basic Programs to a Modern Machine, possibly using HPDrive software over HPIB?

Paul Berger

On 2020-02-20 9:00 p.m., Craig Ruff wrote:

On Feb 20, 2020, at 3:22 PM, greg.linder@... wrote:

I recently picked up an HP 4955A Protocol Analyzer. Although my bench is stacked with HP vintage test equipment in daily use, this is my first fun foray into the world of pre-90's HP computing. I picked this up because it's apparently an HP9825 inside, and the one I have has the Basic option.
Do you mean the 9831? Same basic hardware, slightly different keys and ROMs to handle the Basic language.

There was another thread here about HP9825 mass storage options, and there was some question as to whether or not the HPDrive project works with this era of machine. has some text saying this is possible, I do not have a 9831 so I can't vouch for that. You'd need the 98034 HP-IB interface obviously. However does not have any mention of being able to use an HP-IB interface.

According to Ansgar's site the processor in the 4955A is the same hybrid that was used for the PPU in the 9845A that lacks the Advanced Math Chip in other words it is a hybrid processor with full 16 bit addressing and no floating point.  I ran across some pictures of the inside of one and it has a  TACO chip for the tape controller unlike the board full of TTL and analog chips in the 9825.


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