I need help identifying a Tek scope plugin, for the most obscure reason you can possibly imagine...
First two (huge) photos:
https://datamuseum.dk/bits/30006763https://datamuseum.dk/bits/30006749These photos were taken in Stockholm in early 1955 by Bent Scharøe Petersen, and show the setup he used to investigate if the brand new "magnetic core memory" technology was any use for the IAS-derived computers being built in Sweden and Denmark at the time (BESK, SMIL, DASK)
There are also photos of scope-traces, with handwritten descriptions which either read "20µs/cm" or maybe "20ns/cm":
https://datamuseum.dk/bits/30006678So which is it ?
The scope is a Tek 535, which does not seem to have a serial number.
But I have been unable to figure out if the plugin is 53A or 53B ?
My personal guess is that it "20ns/cm", mostly because "20µs/cm" would make the signals very slow compared to the IAS-derived computers.
If it is 20ns/cm, the signal is 25 MHz, and as I understand it, the 735 should be able to do that with a 53B ?
Thanks for any help.
PS: All the 200+ pictures are here:
https://datamuseum.dk/wiki/Bits:Keyword/PERSONS/BENT_SCHAR%C3%98E_PETERSEN/PHOTOS