lisa@m2xenix.UUCP (Lisa Gronke) (02/11/90)
In article <DaJ9D3w160w@darkside.com> watcher@darkside.com (the Watcher) writes: > to get any performance at all out of the antique apple // 8-bit > machines, EVERYTHING is written entirely in 6502/65C02 assembly. > both ProDOS and ProTERM are so written. for a machine as small as > that, there is no room for the overhead required by a compiler, > much less for that of an interpreter. nonetheless, a decent BBS > can be written in applesloth if enough of it is done in assembly > and it is married closely to both the interpreter and the operating > system. i know it's possible because i've done it. it can be made > fast enough that people calling in would never guess it was "only" > an apple //. and that's without an accelerator card.. Your logic overwhelms me. 'Tis true that well written assembly language (for any microprocessor) is going to produce the smallest, fastest running, tightest machine language code. Assembly language programs are also less portable, harder to debug and more difficult to modify and maintain than programs written in a higher level language. I don't know what you mean by "overhead required by a compiler". Yes, the machine level code produced by a (native code) compiler may be slightly larger than equivalent code written in assembly language. But some compilers (Aztec C for example) produce assembly language as an intermediate (which can be optimized by hand if you are so inclined) and MANY compilers allow you to link in assembler object modules. ProTERM was written (at least partly) by Greg Schaefer. Before Greg went to work for Checkmate he spent a long time writing Apple BBS software. Early versions of GBBS were written mostly in Applesoft (Apple DOS 3.3) and were pretty slow. When Greg wrote GBBS Pro in 1985, he created a language called ACOS and wrote an ACOS compiler that is part of the GBBS Pro package. GBBS Pro BBS software is written in ACOS (the BBS source code is supplied and can be easily modified). I do not know what language the ACOS compiler was written in. The compiler and the runtime routines are part of ACOS.OBJ which is is RAM when the BBS is running. GBBS Pro is currently the most popular BBS software for the Apple. I ran a GBBS system for four years and never heard any complaints about it being slow (with a 2400 bps modem). ProDOS was probably written mostly or entirely in assembly language. I dunno about ProTERM. It could be written in C (using a cross-compiler) with time critical parts in assembly language. I suppose there are people who can tell by disassembling object code whether it was produced by a compiler (and which one), but I am not one of them. I agree with your comment about Applesoft. I used Apples in a laboratory setting for gathering realtime (analog to digital) data. Very often the rest of the program was very simple and could easily be done in Applesoft.