Oscilloscope question

[Tony Duell]

> > The manuals have really gone down for more recent 'scopes. You don't even 
> > get a schematic now...
> 
> Ah, but the 466 manual has pull-out schematics and parts lists for every
> single major module (basically every single PCB). I try and avoid recent
> hardware due to the lack of schematics and service data, although the same
> applies (to a lesser degree) to older equipment. I'm after a maintenance
> manual for a Solartron 7150 - I've got the operator's manual but I want the

My first 'scope, I still have it, was a Solartron CD1400. It came not 
only with a computer operating/service manual (including schematics), but 
also a quick-reference guide that slotted into a metal pocket on the back 
of the 'scope. That contained abridged operating instructions _and_ the 
full schematics.

Solartrond DVM manuals (and the manual for the DTU [1]) contain 
schematics, or at least the oens I have do.

[1] Data Transfer Unit. A data logger without the ADC. It connected to 
the printer output port on just about any DVM, translated the data a 
digit at a time into any up-to-8-bit code (there was a 16*8 diode matrix 
ROM) and then conencted to a teletype or Facit 4070 tape punch. The thing 
could take relay boards to connect several inputs sequentially to the 
DVM, a clock board that could cause it to take readings ever so often 
(and output the time to the tty or punch), and so on. Quite an 
interesting piece of history.

> schematics for reference (in case I end up fixing it at some point). I also
> want to know which chip(s) to pull and read out in an EPROM burner. Firmware
> ROMs don't last forever :)
> 
> Speaking of which, the Tek 466 manual also includes a hex dump of the 6301
> (?) PROM that runs the storage subsystem. Tek even included a state
> transition diagram...

That was quite common at one time. DEC PDP11 and PDP8 manuals often 
included ROM dumps, flowcharts, state diagrams, and so on. These machines 
wre _documented_

Alas I only have the preliminary manual for my Philips P854, so I am 
laking the mciroocde source. I do have schematics. I also have the manual 
for the 4-channel serial card. This is microprocessor based (I think 
8085), and the manual includes a sourve listing of the control ROM. The 
manual for the SMPSU contains a couple of pages of waveforms round the 
chopper circuit. It warns that this is live to mains, and that the PSU 
should be run from an isolating transformer for these measurements. 
Should this be impossible, it suggests removing the mains earth lead from 
the 'scope and 'floating it'. Somehow the idea of a 'scope with the 
chasiss at about 120V wet local ground (the mains input of the SMPSU is 
the standard bridge rectifier cirucit) doesn't thrill me...

-tony