Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!indri!nic.MR.NET!umn-cs!meccts!viper!dave From: dave@viper.Lynx.MN.Org (David Messer) Newsgroups: comp.unix.microport Subject: Re: Microport System V/AT Assembly Language not documented Keywords: Microport, UNIX, System V/AT, as(1), Assembler, COFF. Message-ID: <1865@viper.Lynx.MN.Org> Date: 7 Feb 89 06:24:29 GMT References: <750@cgch.UUCP> Reply-To: dave@viper.Lynx.MN.Org (David Messer) Organization: Lynx Data Systems, Eagan, MN Lines: 37 In article <750@cgch.UUCP> whna@cgcha.uucp (Heinz Naef) writes: >The assembly language processed by the as(1) command of Microport System V/AT >has a completely different semantics, different instruction mnemonics and a >different assembler control (macro) language than usual assemblers for the >80x86 personal computers. It's pretty close to PDP-11 assembler though... :-) >When writing a device driver at the lowest level (i. e. not on top of another >device driver) then there is a need to develop certain parts in assembly >language. With the documentation supplied by Microport for the System V/AT >program development and runtime system, it is *impossible* to even attempt to >write a minimum assembler program. Compared to the excellent documentation of >the linkkit, it is strange that there is no chapter on usage of the assembler >and on coding guidelines. It is difficult, but not quite impossible. I wrote a driver for the IBM joystick port that incorporated a small assembly language routine to access the hardware. (It is highly timing dependent.) What I did was write a C program that did approximatly what I wanted and generated an assembly language version using the C-compiler. (I.e. the command "cc -S file.c" produces file.s) I then hacked this file to do what I wanted. I posted this driver a year or so ago, but if there is interest, I'll post it again. I am curious as to what you are doing that requires assembly-language. Unless you have extreme timing or efficiency requirements, there isn't very much that you can't do in C. -- _____________________________________________________________________________ __ _ _ _ David Messer - Lynx Data Systems / ) / ' ) ) ) dave@Lynx.MN.Org -or- / / __. , __o __/ / / / _ _ _ _ __ ...{amdahl,hpda}!bungia! /__/_(_/|_\\/ <__(_/_ / ' (_