On 2013-07-27, Jim Wilkins wrote:
"DoN. Nichols" wrote in message
...

I wounder how a machine control program which resembles Pascal
would be to work with.

Enjoy,
DoN.

The semiconductor test stations I worked on used a DEC dialect of
Pascal, with a few Assembly hardware drivers. Programming test
routines wasn't difficult as long as we paid close attention to
variable typing, which meant bits and short integers in that
application. We designed the hardware registers to mesh cleanly, like
one status bit per byte rather than grouping and masking them.

O.K. Made it a bit more tolerable. The Pascal I used (and this
was in a database program) would not allow assignment of data between
different length string variables -- unless you did it one byte at a
time. A real pain, and a bunch of functions specifically for that.

But -- it *did* handle random access files, and that plus the
RECORD data type made it quite good for the application, other than the
string assignment pain.

I've written a fair amount of hardware interfacing code in QBasic,
which is part way between Pascal and C, with the structure and typing
available but not as mandatory, and a single level of pointers that
enables reckless variable abuse such as embedding a machine language
interrupt routine as a String.

O.K. Wasn't QBasic one of the compiled ones for CP/M? My above
Pascal programs were on an OS-9 system (the real OS-9, not the much
later Mac OS-9 -- the last gasp before they went unix based. :-)

I eventually ported that program from Pascal to C (once I got a
v7 unix box under a 68000 CPU), and that made some things much easier,
but I had to use a combination of bitmapped variables to emulate the SET
variable from Pascal -- which I had also used. :-)

It was one good way to learn both languages at the application
level.

I really liked having GOTO for exception handlers so they didn't
clutter the main DO Loop structure. I wasn't about to ask the
professor for formal permission to do an emergency shutdown.

:-)

The last step in the test station's troubleshooting procedure gave the
software manager's home phone number. He wasn't too happy when
National Semiconductor called him at 3AM Eastern time.

So the troubleshooting procedure did not quite anticipate
everything. :-) I presume that he had given permission for his phone
number to be in there? And were there provisions for updating that when
the manager went on to another company or another job within this
company?

Enjoy,
DoN.

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