Polar Instruments B2000 uP Bus Tester - Page 1
Forum section: electronics / testgear

author: pamphonica
author_rank: Regular Contributor
timestamp: March 05, 2023, 07:08:26 pm
content: Does anyone have one of these Polar Instruments B2000A testers? It plugs into the uP socket on an SBC and can run simple routines to check RAM, ROM, etc.I need to buy (or make) some extra personality modules for this tester. I have two 8085 modules but no Z80, 6800 or 6502.I also have a B2000A POD and have no idea how to use it or what it is for.Are there any experts (or even just users) out there who have information or spare modules?thanksJeremy

author: pamphonica
author_rank: Regular Contributor
timestamp: April 29, 2023, 03:47:29 pm
content: A quick update. I designed some small PCBs to make universal personality modules for the B2000 and had them made in China.I also laid out a spreadsheet of all the required interconnecting links for each processor type.I put appropriate links onto a board so that my B2000 can "speak" 6502 and all is now working well. The B2000 has been faultfinding an AIM-65.If anyone needs universal personality boards for their B2000 drop me a line.BTW the B2000A "pod" is just a personality board with links that swap various signals so that an 8031 system can be tested using the 8085 configuration on the B2000. That is what gave me the idea of getting universal boards made.thanksJeremy

author: Stray Electron
author_rank: Super Contributor
timestamp: April 29, 2023, 08:16:53 pm
content: I've never heard of a Polar Instruments B2000A. How about posting up some pictures? Otherwise it sounds a lot like a Fluke 9010 Micro System Troubleshooter. You might want to look into those, they have some outstanding capabilities. But GOOD LUCK finding one that doesn't cost a months wages! They're still in VERY high demand by people that repair the uProcessor based arcade games.

author: pamphonica
author_rank: Regular Contributor
timestamp: April 30, 2023, 01:27:37 pm
content: It's a tiny device, so sits well on the workbench.The manual is here:http://gamearchive.askey.org/General/Test_Equipment/Polar/PolarB2000.pdf.The manual is actually very helpful, and contains a full circuit diagram.Photos of my B2000 are attached. Mine needed a new backup battery. I replaced the round type with a Varta pack that fitted the holes, albeit at a slant.I also replaced C22, the 47uF tantalum which decouples the main +5V rail with a modern 47uF electrolytic.The cables are straightforward. IDC40 (2x20) to an IDC 40-pin DIP header. But in mine, the "pin1" stripe does not match pin 1 on the connectors, no idea why.The device comes pre-configured to ONE of the available Z80/8085/6800/6502 processors, defined by a small internal personality board.Mine came labelled Z80 but containing an 8085 board. It also had an external pod marked B2000A. That seems to further swap lines, so an 8031 system can be tested using the 8085 personality module.I had to make up a spreadsheet to decode the odd pin assignments across the personality board. That is also attached. The external pins on the ribbon cable/DIL plug do NOT match the pin numbering on the socket on the B2000 PCB that holds the personality module. Follow the spreadsheet!If you make up your own personality modules, use Column A "Int Bus" on the B2000 side and patch that to the pins shown as "Ext Ribbon" on the device side.These little devices are a huge help in doing board diagnosis. The B2000 was really designed for production line testing, where a short test suite was run on each board, with printed results.-Jeremy(having problems attaching lots of files - see next post for more photos)

author: pamphonica
author_rank: Regular Contributor
timestamp: April 30, 2023, 01:29:22 pm
content: More photos-Jeremy

author: pamphonica
author_rank: Regular Contributor
timestamp: April 30, 2023, 01:30:24 pm
content: Spreadsheet for making up personality modules.-Jeremy

author: pamphonica
author_rank: Regular Contributor
timestamp: April 30, 2023, 01:40:28 pm
content: And finally, photos of the B2000A pod and its internal layout.-Jeremy

author: Azure
author_rank: Contributor
timestamp: June 30, 2024, 11:52:01 am
content: Late to the game. Any chance you can post or pm an image of the EPROM?

author: bouncingboffin
author_rank: Newbie
timestamp: February 21, 2025, 09:45:45 am
content: Even later to the game, I have just got a B2000A for BBC Micro diagnostics, but it needs a LOT of tlc before I can even do that due to the dreaded Varta leakagehttps://www.vintage-radio.net/forum/showpost.php?p=1555405there is an EPROM image that appears to be an earlier version compared to what is inside my B2000A marked NP27C 8705. I have included the file here just in case the source website vanishes. The pod for the BBC Micro contains some logic and a reed relay module.Polar-B2000A_NP27_8543.zip(11.01 kB - downloaded 24 times.)I have just removed the EPROM from my B2000A and attached it as a ZIP file.B2000A NP27C 8705.zip(8.16 kB - downloaded 19 times.)Oh and just to make folk laugh, whoever laid this POD board out didn't realise that IDC pin numbering goes in columns, not rows. So they've marked pin#1 and pin #40 where it should be pin #2

author: bouncingboffin
author_rank: Newbie
timestamp: March 16, 2025, 03:16:34 pm
content: I has been the best part of a month. The B2000A was in a far worse state than I thought (think Mac II SE) The components around the battery fell away when poked with a screwdriver. All the sockets were corroded, even at the opposite end of the board. I decided to redraw the PCB and I'm in the final stages of this, battling the schematic vs. real PCB differences and the peculiar non-standard IDC connector that the person at Polar Instruments used.

author: bouncingboffin
author_rank: Newbie
timestamp: April 24, 2025, 10:41:48 pm
content: I finished the PCB design and got it made at JLCPCB, as usual, they did a tip-top jobNow to get the printer working, then try the PSU (I had to rewire the rear panel as someone pinched the wire, grommet and switch)

author: bouncingboffin
author_rank: Newbie
timestamp: April 25, 2025, 10:14:14 pm
content: Oh well, the printer is dead. I made the mistake of powering the mechanism from the bench supply whilst debugging the scroll mechanism. The printer ate itself and tore the ribbon cable from the print head. Unfortunately, what I assumed would be a cheap fix isn't. Seiko stopped making the MTP201-24B-E a few years ago and the scalpers want hundreds of bucks for a $20 printer because manufacturers of essential (aka rip-off) medical equipment put this printer into their products - now of course, a medical equipment spare is always $$$$$ despite its original cost. Without a printer the B2000A is more-or-less useless, so all the work I have done is for nothing. I'm kicking myself for not taking much, much more care by checking the price and availability of the printer before poking around with it. This has to be the largest amount of work I have put into something for it to become worthless in a few seconds.D'oh!

author: bouncingboffin
author_rank: Newbie
timestamp: May 04, 2025, 10:18:47 pm
content: Some good news. I have been given a boxed MPF-IP - a thermal printer add-on for the 1980s vintage Microprofessor MPF-1 Plus. It has the same printer with a minor wiring change. So the upside of that is I'm back in business.I also found out why the original printer didn't do anything, the cable had reacted with the electrolyte and the corrosion spread up the ribbon cable into the IDC->PCB connector and ate the contacts. I saw a gentle tinge of green, but assumed that the corrosion couldn't reach areas that weren't on the PCB (wrong, d'oh!)I am awaiting parts from Mouser to make a whole new cable, the 14 pin IDC isn't something I have, 10, 20, 24, 34, 40 and 50 way are all I have.The rest of it appears to function, the power supply whine is noticeable, but not with the lid on.The IDC connector at the B2000A main board looks like this. I cut this off and remade it, but most of the pins did not connect.The other end didn't look like it had a problem.Popping the clamp off the top revealed the truth, it's done for.The Microprofessor can't profess anything on paper for now

author: pamphonica
author_rank: Regular Contributor
timestamp: June 22, 2025, 06:36:17 pm
content: Wow, bouncingboffin, I missed all these excellent updates re the B2000A from you. Mine is a humble 2000 and I would love to upgrade it to a 2000A so I can more easily use external pods instead of internal jumper boards. I already have a Z80 pod and an unusual 8085 to 8031 pod both for the B2000A.Could you let me have the B2000A pcb files so I can order from jlpcb? I am happy to pass on some of my personality boards if they are of use to you.Well done on the printer substitution!All bestJeremy

author: pamphonica
author_rank: Regular Contributor
timestamp: June 22, 2025, 06:39:59 pm
content: And I only just found out that Polar have the full B2000/B2000A service manual on their website.https://www.polarinstruments.com/man/service/B2000%20&%20B2000A%20Service%20manual.pdf