Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!philabs!cmcl2!phri!roy From: roy@phri.UUCP (Roy Smith) Newsgroups: net.arch Subject: Using C as an aid to hand writing assembler Message-ID: <2336@phri.UUCP> Date: Tue, 6-May-86 18:54:11 EDT Article-I.D.: phri.2336 Posted: Tue May 6 18:54:11 1986 Date-Received: Thu, 8-May-86 20:43:47 EDT References: <817@harvard.UUCP> <460@cubsvax.UUCP> Reply-To: roy@phri.UUCP (Roy Smith) Organization: Public Health Research Inst. (NY, NY) Lines: 34 Original-Subject: Re: Arch support for C In article <399@ccird1.UUCP> rb@ccird1.UUCP (Rex Ballard) writes: > [...] C was written for PDP-11s, as sort of a GENERIC ASSEMBLER. When > reduced to it's simplest constructs, that is exactly what C is. Some years ago when I was learning 6800 assembler (anybody remember D2 kits?) I used to first write everything in C and then hand compile it into M6800 asm. When I told my professor (are you reading this Professor Efe?) that I did this instead of drawing flow-charts, he laughed at me, but as long as you keep your code simple, the conversion is trivial and can be done in your head as fast as you can write down the asm code. Perhaps the simplicity of the M6800 (dare I call it a RISC machine? :-)) makes this easier than for something like a vax, but I can still do it; let's see: char i, j; j = 0; for (i = 0; i <= 10; i++) j = j + i; clr j loop1: clr i cmp i, #10 bge out lda j adda i sta j lda i inca sta i bra loop1: out: -- Roy Smith, {allegra,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016