[net.micro.pc] Softalk's Screen Saver

HFISCHER%USC-ECLB%MINET-CPO-EM@sri-unix.UUCP (12/15/83)

I am submitting the Screen Saver program from the December Softalk
to the Info-IBMPC library.

I have only found one product Screen Saver is not compatible with,
IBM's APL language.  (It seems to work well so far with all else I
have tried, including word processors, Kermit, Basic, Logo, debug...)

With APL the problem is that once APL finishes loading, when you press
a key strange things happen, such as garbage spitting on the screen
and the CPU locking up (unloadable, and, yes, believe it or not,
un-cold-startable).

I have never seen any software which makes the processor unable to
restart by cycling power, except scrnsave and APL.  Apparently
something somewhere in the system has a large electrolytic capacitor
which takes forever to discharge, and that item is screwed up with
this software combination.  Waiting a good half minute apparently is
enough to clear this incredibly strange situation.

The only fix I can think of is to have your APL startup procedure peek
at the interrupt vector and if it sees scrnsave, quit right there.

Herm Fischer

[SCRNSAVE.BAS has been added to the Info-IBMPC library. -Ed.]