Re: [TUHS] Redoing "V6on286" or porting V7...?

i don't know that it's a squese. a version of v6 ran on an lsi-11 with very little ram. there is only two process required to run in v6, init and the shell. sched doesn't count; it has no user space. very good point. it'll be easier that i thought. the mit is already ported. every thing you said about how ugly the x86 is and how nice the pdp-11 was, i agree with. i have lived with both of them and with the 68k. although the 68k's A and D registers are kind of a hacky. but not mater, mit's already done the work. as far as trying to optimize the register use, i think that for modern pentium processors it's not that important. L1 caches are very fast and function about as fast as local registers anyway. this the the good thing about a very bad instruction set with too few registers. the vendor has to invent very clever ways to stay competitive with better systems. in a way the hardware is doing all the optimzation for us. again, no port required. the mit x86 stuff has already done that. i have code with the following readme. --- Directory setup: c86, lib86: for 8087-equiped systems. nc86,nlib86: for non-8087 systems. You should install the following files into some directory on your search path (on our system we use /usr/local): cc86 ; shell script implements "cc" but for 8086 a86/a86 ; the assembler a86/ld86 ; the loader a86/cvt86 ; .ld output to .com file (a la IBM DOS) conversion c86/c86 ; the C compiler Regular 4.1BSD programs used: ar ; used for preparing loader libraries /lib/cpp ; C preprocessor The cc86 script expects to find the libc.a and crt files in /projects/compilers/8086/lib86 -- if you don't put them there, you'll have to update cc86... The compiler produces assembly language output suitable for a86. It is a 16-bit compiler; output code does not touch the segment regs, so it is possible to have separate instruction and data segments (see lib86/csu/crt0.a86 for the start up routine we use on our IBM Personal computer to set up the segment regs, etc. from info in the .com file). Currently floating point and long arithmetic is implemented using 8087 instructions. Although the assembler produces ".b" files, they have exactly the same format as ".o" files under 4.1BSD -- things like nm and size will work, and, most importantly, ld. Using ld with the -N, -X and -r options (see cc86 for an example) will produce a file that cvt86 can convert into an IBM DOS format .com file for the IBM Personal Computer. --- looking at the source files, it's definitly PCC. (and it already does the =+ stuff.) you keep tempting me! (get behind me, Satan!)