1. TekScopes@groups.io

Re: Introduction of myself!

David Hess
 

That is new since I last visited Hakanh's site. He has been busy.

That modification is not the same as the later combined RAM and ROM
card which was used in the late 7854s.

Since it uses the original ROM board, you would still need to find
2763 pinout EPROMs, the FLPA, and whatever part would be needed for
the 2k x 8 memories.

As a practical matter the easiest way to update it is burn a ROM image
which combines the original ROMs and the patch data from the FLPA and
EPROMs into 4 x 2763 pinout EPROMs which are still available; I think
this combined image is available online. 2764s can be used instead if
the board is modified or maybe if an interposed is used; interposers
to convert the 2763 pinout to the 2764 pinout are common for video
game retrofits.

It was a while ago now but I searched for this information before
considering the 7854 and then when I got one, it was a late model that
used the alternative combined RAM and ROM board which I had no idea
even existed.

On 16 Feb 2016 15:12:53 -0800, you wrote:

Raymond,

I was referring to the "Firmware upgrade and ROM reliability improvement" part of the "Tek mod kits and parts replacement" page you sent me the link to for the 7T11/A mod parts list. I surfed thru it for a few minutes and looked at the parts that pertain to equipment I have - so I know what should have been done if they were properly updated before I obtained them.

That specific update for the 7854 sounds to me to be a fairly important, and possibly critical one after all the time that has passed since the year it should have been updated in.

This is the link to the specific Mod page I was speaking of:

http://www.hakanh.com/dl/docs/kitinstructions/045-0056-00.pdf http://www.hakanh.com/dl/docs/kitinstructions/045-0056-00.pdf

Also, this is the specific unit I purchased. B030771 S/N - My guess is that this is of the early version production.
http://www.ebay.com/itm/Tektronix-7854-Oscilloscope-Mainframe-with-Waveform-Calculator-for-Repair-/291679909626?_trksid=p2047675.l2557&;ssPageName=STRK%3AMEBIDX%3AIT&nma=true&si=cZheso%252BTqMILxftiQZIuAGiBXu4%253D&orig_cvip=true&rt=nc http://www.ebay.com/itm/Tektronix-7854-Oscilloscope-Mainframe-with-Waveform-Calculator-for-Repair-/291679909626?_trksid=p2047675.l2557&;ssPageName=STRK%3AMEBIDX%3AIT&nma=true&si=cZheso%252BTqMILxftiQZIuAGiBXu4%253D&orig_cvip=true&rt=nc
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