[volt-nuts] Solartron 7081 ROM images

[Михаил]

Hi, David!
Solartron (Ametek) engineer not right. 2564 and 2764 EPROMs are not
interchangable due to pinout differences.
I have a very old 7081 (#231) with both ROM-sets dated 1984. After about three
months of exploring now I'm trying to write an article about Solartron 7081
internal features, bugs and workarounds. But it not easy for me.
The day before New Year, I'm found a solution for the 7081 drift correction
errata. This errata is related to Floating Logic firmware, located in the IC803.
IC803 ROM firmware is more critical than Earthy Processors ROM-set, because it
contains all of the hardware-specific delays, registers look-up tables,
two complicated finite-state machines, virtual timers, software GLUGs
integrator, interboard messagind system interface e.t.c. If you are interested
in, the solution in this file: http://www.fileserve.com/file/wntURSH/Patch_ic803.rar

Mickle T.


Tuesday, January 3, 2012, 12:36:10 PM, you wrote:
DCP> On 22 December I received an email from a Solartron (Ametek) engineer (one
DCP> of the very few remaining) who had found my web site.

DCP> Amongst other things he said:

DCP> ==== QUOTE ====
DCP> Incidentally did you know that the 7081 and 7071 are essentially the same
DCP> instrument? The reference zener diodes were soaked for several weeks in an
DCP> oven which temperature cycled them and each diode was checked regularly for
DCP> stability. The very best ones were selected to go in the tighter specified
DCP> 7081. The not so good ones went in the 7071. Otherwise the only difference
DCP> is the front panel and the contents of the EPROMS. The 7081 has an 8 x
DCP> nines (51 seconds integration time) button. On the 7071 this button is not
DCP> present and the firmware limits the integration time to  3.2 seconds (7 x
DCP> nines display). Both units can go down to 3 nines (1.56mS integration time,
DCP> 100 readings/second) when under remote control although of course this
DCP> rather defeats the object of having such an long scale instrument. 

DCP> Out of interest I just took the lid off my 7081 (serial 104) to see what
DCP> firmware it has in it. The EPROMS which are labelled issue (DD) have the
DCP> same checksums as in your article and looking at records this seems to be
DCP> the last version produced. The only difference is that mine are 2764 rather
DCP> than the 2564 in yours. (They are of course interchangable). 
DCP> ==== END QUOTE ====

DCP> It's nice to have confirmation of my suspicion that the ROM set I have IS the final revision.

DCP> Cheers
DCP> Dave