[time-nuts] Fine print on HP 5334B

John Miles jmiles at pop.net
Fri Feb 23 02:20:13 UTC 2007


It's a 6800 with a biphase 1.25-MHz clock.  It is likely to be tricky to
upgrade the CPU because you don't necessarily know if there are any critical
loops that depend on a particular clock cycle time.

There's a disassembler here (M68DIS):
http://www.simtel.net/category.php%5Bid%5D73%5BSiteID%5Dfilebasket
I've used it to delve into the Tek 490-series ROMs a bit.

Also, in time-interval mode, there is a "computer dump" mode that allows you
to make measurements much faster by moving the vernier calculations to the
host.  The count-chain outputs are returned in a 5-byte binary block.  In
measurements that take the mean or std dev of a lot of readings, it's tough
to say whether it's faster to let the CPU do the math or send each reading
to the host on an individual basis.  Would be interesting to try.

-- john, KE5FX

> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
> Behalf Of Jack Hudler
> Sent: Thursday, February 22, 2007 5:35 PM
> To: 'Discussion of precise time and frequency measurement'
> Subject: Re: [time-nuts] Fine print on HP 5334B
>
>
> Wow that's an easy 8bit instruction set.
> If someone dumped the EEPROM's I could whip up a disassembler. They even
> have a 6800 simulator on sourceforge.
> But, that would be the easy part, now you'd have to understand what it's
> doing and why.
> Of course some HP benefactor could accidently send the source...
>
> Jack
>





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