[time-nuts] IEEE-488 HP-IB GP-IB Chips

Brooke Clarke brooke at pacific.net
Tue Apr 26 14:16:54 EDT 2005


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
>
>
>
>jim_johnson at agilent.com 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: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
>>>>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
>>>>
>>>>
>>>>jim_johnson at agilent.com 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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>>>
>>>      
>>>
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>>
>>    
>>
>
>
>
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>  
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