Re: 11801 NVRAM
CSA803A has tonnes of inbuilt telecom eye-diagram masks, this was its USP for telecom industry (who always had money.)
Each pixel on the display has a deep accumulation bucket that you can see in graded mode but only fully appreciate by downloading the raw screen data.
What you see: http://www.leobodnar.com/files/CSA803A-screenshot.png
What it actually is: http://www.leobodnar.com/files/CSA803-graded.png
Isn't this almost analogue? http://www.leobodnar.com/files/CSA803-graded2.png
I have recently replaced CRT in my HP89410A with an LCD display. Might try the same trick with CSA803A when I get free time and be bored.
The hardware on all 11800 boards is i80186 so a cunning enthusiast can easily hack and play with the code as they please. The only problem is that every subroutine seems to use its own segment which is very unusual for PC style software.