[fpc-other] Yet another mainframe emulator

[Bernd Oppolzer]

Am 08.10.2013 15:54, schrieb Saunders, Rich:
> Thanks for the correction about descriptor architecture. I thought you 
> were referring to the file system tagging stuff.
>
> I would hope that someday the good ideas of the past would find their 
> way back into general use.
>
> I also remember some really awesome attributes of VMS that have been 
> discarded. At least HP has been keeping OpenVMS alive so people can 
> actually see what it can do. Probably the most secure and reliable OS 
> in general use today. 17 year cluster uptime? Amazing.
>
If we're discussing obsolete historic platforms, I would like to add my 
story, too.
It sounds a little bit similar.

In Germany, we had a mainframe platform from the now non-existent computer
manufacturer Telefunken, starting with the TR4 in the early 60s, which was,
according to Dijkstra, a "hardware implementation of ALGOL". It had 48 bit
words, and every word had two tag bits, which telled if the word was 
fixed point,
floating point, instructions (two 24 bit instructions) or text (for 
example 6 characters,
but there were other formats, too). If you used the wrong instruction 
(which
didn't match the tag bits), you got an error called "Typenkennungs-Alarm".
This way it was possible for example to detect the use of uninitialized 
variables
at runtime.

The offspring was the TR 440, which was a large time-sharing machine
with display monitors, virtual storage and (in the end) up to 3 processors.
It was used at the universities in Germany througout the 70s and early 80s
and most of the students of Computer Science (called Informatik in Germany)
grew up with this machines at this time. There was a Pascal compiler 
written
in Kaiserslautern first and completed in Stuttgart later, which was a 
port of
the Zurich P4 compiler, and it had all the features, that were normal at 
this
time, that is, an interactive debugger, and dumps which printed the 
variables
in the layout of the programming language, not hexadecimal, that is:
variable names and values.

It was in use at the Stuttgart university from 1973 to 1980, and I studied
Informatik there from 1977 until 1985, so I spent some days and nights
with this machine. After that, we got a VAX 11/780; that was a very nice
machine, too.

The Telefunken manuals are at the Deutsches Museum in Munich,
but also at bitsavers.org - I have some private copies. There are not
many people today that still know this platform.

Kind regards

Bernd