Elevators (was: Einstein (was: ambiguous))

Bob Stout Bob.Stout at p6.f506.n106.z1.fidonet.org
Thu Nov 9 21:53:22 AEST 1989


In an article of <2 Nov 89 18:17:31 GMT>, (Norman Diamond) writes:
 >>In article <1159.25475CBB at urchin.fidonet.org> 
 >Bob.Stout at p6.f506.n106.z1.fidonet.org (Bob Stout) writes:
 >>
 >>>For example, an elevator controller (a typical  
 >>>job for me) may be an exercise in AI programming, but if you try to 
 >tell a  
 >>
 >>But it also can't be programmed in C!!!!  ANSI says that the execution
 >>character set must include a carriage return, audible alarm (well --
 >>I guess an elevator has that), vertical tab (does an elevator have
 >>that?), horizontal tab, and a bunch of ASCII-like characters.  And
 >>you gotta have fseek()...

  Uh, I hate to tell you this, but there's an awful lot of embedded  
applications, things like microwave ovens, TV's, VCR's, automotive systems,  
laser printers, SCADA systems, and controllers of all types programmed in C.  
So what if the character set is never used? So what if there's no file I/O? So  
what if it runs out of ROM instead of in a hosted environment? Look around -  
there's a whole world of computers you never see simply because they don't  
*look* like computers. And there are plenty of C compilers for chips like the  
805x, 6303, 65xx, 68xx, and lots more you probably never heard of. Besides,  
one of the hottest ways of building small quantities of specialized  
controllers these days is using 80x86 based controllers running DOS  
look-alikes out of ROM. Files, if any, can be in battery-backed SRAM or  
EEPROM, with write-protected files being read out of ROM. Console I/O is the  
terminal you hook to the RS-232 port for running diagnostics.

  Sorry I missed this message the first time around - but in all honesty, I  
never expected such parochialism in this newsgroup. This stuff has been around  
for years - I've been using C in embedded applications starting with 6502 uP's  
since '81 or so. 



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