Messages in this thread | | | Date | Sun, 02 Dec 2007 20:23:12 -0500 | From | Bill Davidsen <> | Subject | Re: Kernel Development & Objective-C |
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Alan Cox wrote: >> Well, original C allowed you to do what you wanted with pointers (I used >> to teach that back when K&R was "the" C manual). Now people which about >> having pointers outside the array, which is a crock in practice, as long >> as you don't actually /use/ an out of range value. >> > > Actually the standards had good reasons to bar this use, because many > runtime environments used segmentation and unsigned segment offsets. On a > 286 you could get into quite a mess with out of array reference tricks. > > >> variable with the address of the start. I was more familiar with the B >> stuff, I wrote both the interpreter and the code generator+library for >> the 8080 and GE600 machines. B on MULTICS, those were the days... :-D >> > > B on Honeywell L66, so that may well have been a relative of your code > generator ? > > Probably the Bell Labs one. I did an optimizer on the Pcode which caught jumps to jumps, then had separate 8080 and L66 code generators into GMAP on the GE and the CP/M assembler or the Intel (ISIS) assembler for 8080. There was also an 8085 code generator using the "ten undocumented instructions" from the Dr Dobbs article. GE actually had a contract with Intel to provide CPUs with those instructions, and we used them in the Terminet(r) printers.
Those were the days ;-)
-- Bill Davidsen <davidsen@tmr.com> "Woe unto the statesman who makes war without a reason that will still be valid when the war is over..." Otto von Bismark
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