I'm told that you can also buy a PDP emulator card for your PC so that
your software can run sans modifications on a more modern piece of
hardware.
> Code was written in assembler back when these were popular. Makes the
> system hard to migrate with out total re-engineering of the system.
A lot CTC software still runs on PDP11's. QR still has some of this
gear in various parts of the state, but it is being phased out in
favour of the UTC system (PC based - running OS/2.)
The Y2K bug is actually more a firmware problem rather than a software
problem. The reason is that although most modern operating systems will
work fine into the next millenium, the PC BIOS is the critical stumbling
block. Regardless of how good your OS is, it still has to grab the
date and time from the system BIOS, and if that's wrong, then so is
your software. Fortunately, most semi-critical systems can be manually
set on New Years Day of 2000 without too much of a problem. Critical
systems have to be upgraded.
CTC, however, is not date-dependant except for the replay facility
because it doesn't have ARS or timetabling. It should happily keep
running regardless of what the date is because all it does is respond
to indications and events out in the field. All critical delays are
actually generated by SSI or relay logic, so CTC doesn't have to
really worry about timing.
Ciao
-- Alex Borodin - Software and Systems Engineer - Queensland Rail Ph: +61-7-3235-2482 Fax:+61-7-3235-2747 "He shall deliver thee in six troubles: yea, in seven there shall no evil touch thee." - Job 5:19