HP 16500B logic analyser

This section is old (circa 2014) and unmaintained. I no longer own a HP 16500B, and can only answer questions from hazy memory. This information is presented as-is.

This was a definite case of “right place at the right time.” I was searching ebay for a HP 16500-series analyser being sold by someone reasonably close to me, and came upon a listing for a HP 16500B which was getting seemingly little interest. A few folks had already asked questions about it, and the seller uploaded a couple of pictures of the machine (including a screenshot of the test screen).

After a bit of umm-ing and aah-ing, I put in a bid for the analyser, and won it for the entirely reasonable (some would say too reasonable) sum of £136. Not too bad. I got a friend to pick it up (she was in the area and offered to help out), and drag it back “up North”. It's turned out to be a better deal than it first appeared…

There were (and still are) three cards installed in the mainframe – the 16550A state/timing Logic Analyser card, and also the 16530A/16531A Digitising Oscilloscope pair (the 530 is the timebase, the 531 is the acquisition card). On top of that, the probe pouch contained a full set of cables and probe pods (including two spare pods) for the LA, and a pair of HP oscilloscope probes.

The software was pretty old (SV 3.04), but included the Symbol Table Utility, which allows a “virtually infinite” number of address symbols to be loaded into the analyser (in comparison to the 1000-symbol limit of the normal Symbol Table)…

I've collected a few useful tools and guides here, which may help other users of the 16500B series analysers.

• Installing a 16555D Deep Memory Logic Analyser card directly above a 16531A Digitising Oscilloscope will cause the LA to fail when the markers are set to Pattern Search mode.
  • The workaround is to install a blanking plate between the 16531A and the 16555D.
  • EDIT 2011-04-12: This may not be true. I found a few damaged PCB tracks on my 16500B's motherboard. After repairing them, the 16555D seems to work fine in any slot.

• Reinstalling the software on a HP 16500B. If your hard drive is pooched (or you've just replaced it with a CompactFlash card), you'll need to do this.
• Installing the E2450A Symbol Table Utility.
• Remote-controlling the 16500B.
• Upgrading the RAM in the 16500B mainframe.

• HP 16500B System Software 3.14. Hosted by Agilent. This is the last version of the 16500B Operating System.
• E2450A Symbol Table Utility 3.06. The last version of the Symbol Table Utility, used to be on the Hewlett-Packard FTP site up to the time of the Agilent spin-off. Includes an 'a.out' format symbol reader that isn't mentioned in the manual.

• 16530A / 16531A – 100MHz, 400MS/s digital sampling oscilloscope modules
  • Service Manual. PDF, scanned from my copy of the manual. This basically amounts to a board-swapping and installation guide. Useful for the interboard wiring diagrams, but not much else.
• E2450A Symbol Table Utility
  • User's Guide. PDF, from Agilent's FTP site. No idea if this is on their website, but it's here…

• If you have a Wireless LAN set up, this is a great way to make the “portable” (HP's terms, not mine!) 16500B a little more portable. Buy a Wireless LAN Bridge like the Edimax EW-7206APG, then set it up in Wireless Client mode. Now connect a short straight-connected Ethernet cable between the bridge and the 16500B, and power both devices up. This works great if your LAN connection is in one room and your workbench is in another, or if you just don't want Cat5 cables snaking all over said workbench.
• If your Ethernet transceiver won't lock into the AUI socket properly, check that the screws on the front of the socket are screwed in (they tend to work loose over time) and that the sliding latch has not been bent. The latch pins can be bent back outwards by levering against the instrument casing with a suitably sized flat-blade screwdriver or similar tool.

• Didier Juges (KO4BB) has collected some useful information about replacing a HP 16500B hard drive with a CompactFlash card.
• Brad has also made a HP 16500B boot from a CF card
• Maurice has written a HP16500B Experiences website, which includes some interesting information about the 16500B's hard disk format (it's byte-swapped FAT16). He also explains how to make the IALDOWN inverse assembler downloader work on modern machines.