🚀 go-pugleaf

"Chris Bigos" <Chris...@COLDmail.com> wrote in message
news:6aie7.52269$e%3.8225465@news2-win.server.ntlworld.com...
> Dear Dan / transatlantic cousins,
>
> I hope I can add my little bit to the shared knowledge in this thread:
>

A WEALTH of great information followed !

>
> > "About 1/4 the way down the left hand side is a square hole. It's where
a
> lighted button went. Any idea what the button was (vainly hoping I can
find
> the correctly labeled button somewhere)? I don't think it was "Power On",
as
> there is a switch on the lower right quadrant labeled that."
>
> This was the '360 compatibility mode' button. I recall it was translucent
> green and engraved "360" rather than "360 MODE" (p/n 5383203 - I have one
> somewhere, perhaps I could JPEG it if you're bent on an accurate
> restoration). The pushbutton was backlighted when 360 compatibility mode
was
> active, which could only be whilst in state 1, 0, or Test in either
> Supervisor or Problem mode. When not in 360 mode the CE was in 9020 mode
(we
> only ever took our CEs out of 9020 mode when running the diagnostic that
> checked that 360 mode worked!).
>

Yikes.  I've never seen a button like that.  My hopes of finding one dimmed.

>
> I wouldn't be surprised if the RPSB instruction (Repack Symbols) takes the
> prize for the most complex instruction ever implemented in the history of
> mainframe computing - certainly of the era. Any comments? (I guess this
> should be a new thread - if there isn't one on this topic already.)
>

I always thought SIE (start interpretative execution) was the most complex
instruction.  As I recall it had its own PoP, or at least a separate
multi-page document.  I don't know how far back it went though.  I ran into
it in the late '80s so perhaps it isn't of the same era.

> Regards
>
> Chris Bigos
>
> FAA Academy 9020 Class of 79/80
>
> Email: Chris...@COLDmail.com
> (Make the obvious temperature change to the spam deflector)
>
>