Hi Rick:
I remember that when the Motorola 6800 first came out (my first computer was a SWTP 6800 based kit) there were a family of 68xxx chips to go with it and one of them was the 68488. But very shortly after that it was common knowledge that there was a problem with it and almost no one was using it.
The TI TMS9914A and NEC uPD7210 chips were much more popular. ines makes a replacement that can be configured as either a 9914 or 7210, see:
http://www.gpib2000.com/chips.htm
I think NI also makes a replacement chip for the NEC. But no one makes a replacement for the Motorola part.
Someone is making new PCBs for the GP-IB interface that goes into the Austron 2100 series Loran-C receivers, but getting the Motorola 68488 and the bus interface chips is very expensive since they are very rare.
73,
Brooke
Rick Karlquist wrote:
I remember back when the 5370B was being designed that there were three vendors who made GP-IB interface chips. All three were implemented incorrectly resulting in bugs, but the bugs were different. All three vendors refused to fix the bugs. There was also an HP made "PHI" chip that interfaced with GP-IB. It might have actually worked correctly. I remember that the HP5183 had a bug where it would go into serial poll by mistake after about 12 hours of continuous bus activity. There was no way to fix this bug, AFAIK.
Rick Karlquist
[EMAIL PROTECTED] said:
Hi David,
Apparently the GPIB fix occurred in the 5370B models only and as far as he knows, there could be some units out there with "bad" firmware in them and some with the GPIB fix. The problem still remains where they didn't change the firmware revision number so there's no way to confirm it one way or the other, besides having your GPIB hang up on you. Sorry, but that's about the best that can be done on this issue. I hope your 5370B is a later model that has the fix in it!
Regards, Jim
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of David Kirkby Sent: Friday, April 15, 2005 1:52 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Difference between HP 5370A and 5370B
[EMAIL PROTECTED] wrote:
Hi again David,
I talked to xxxxx this morning and here's what
he said:
Thanks.
The 5370B has a different processor board than the
"A" model, with on-board RAM (the "A" had a separate
RAM board). The "B" has had an upgrade to its DAC
board. The "B" has a different input module that is
more stable than in the "A". The firmware has had an
upgrade in the "B", as the HPIB (GPIB) would occasionally
hang up in the "A" model. The bad news is that the
newer firmware carries the same rev. number as the old one
so you can't easily tell which one you have installed.
I'm slightly lost there. You seem to be implying the B's have newer firmware than the A's, but then saying its not easy to tell if you have the new firmware, since the revision is the same. If the newer firmware was installed only in B's, then all you would need to do is look at the model number. Clearly then I assume either some B's have the old firmware, or some A's have the new firmware, or perhaps HP would update an A to a B firmware.
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