From uchinews!vixen.cso.uiuc.edu!uwm.edu!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!csus.edu!netcom.com!netcomsv!butch!lscruz!lscruz!not-for-mail Tue Oct 18 20:01:01 CDT 1994 Article: 80177 of alt.folklore.computers Path: uchinews!vixen.cso.uiuc.edu!uwm.edu!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!csus.edu!netcom.com!netcomsv!butch!lscruz!lscruz!not-for-mail From: alan@lscruz.scf.lmsc.lockheed.com (Alan Strassberg) Newsgroups: alt.folklore.computers Subject: Re: What the minimal Unix configuration? Date: 15 Oct 1994 00:39:04 -0700 Organization: Lockheed M & S Co., Santa Cruz, California Lines: 97 Message-ID: <37o0uo$ek8@lscruz.scf.lmsc.lockheed.com> References: <9410102151591.DLITE.rnturn@delphi.com> <37hfkv$nu6@vixen.cso.uiuc.edu> <1994Oct13.133048.1098@muvms6> <37kipb$r30@vixen.cso.uiuc.edu> NNTP-Posting-Host: lscruz.scf.lmsc.lockheed.com Status: R In article <37kipb$r30@vixen.cso.uiuc.edu>, Mark D. Roth wrote: > >Anyone know where I can get a copy of the Z80 UNIX? I'd love to play >with it on my TRS80... :) Sure, no problem. From a posting about 1988 in comp.os.cpm. I have the posting archived somewhere, here's a quick description. It may be on Simtel. UZI: UNIX Z-80 IMPLEMENTATION Written by Douglas Braun Introduction: UZI is an implementation of the Unix kernel written for a Z-80 based computer. It implementts almost all of the functionality of the 7th Edition Unix kernel. UZI was written to run on one specific collection of custom-built hardware, but since it can easily have device drivers added to it, and it does not use any memory management hardware, it should be possible to port it to numerous computers that current use the CP/M operating system. The source code is written mostly in C, and was compiled with The Code Works' Q/C compiler. UZI's code was written from scratch, and contains no AT&T code, so it is not subject to any of AT&T's copyright or licensing restrictions. Numerous 7th Edition programs have been ported to UZI with little or no difficulty, including the complete Bourne shell, ed, sed, dc, cpp, etc. How it works: Since there is no standard memory management hardware on 8080-family computers, UZI uses "total swapping" to achieve multiprocessing. this has two implications: First, UZI requires a reasonably fast hard disk. Second, there is no point in running a different process while a process is waiting for disk I/O. This simplifies the design of the block device drivers, since they do not have to be interrupt-based. UZI itself occupies the upper 32K of memory, and the currently running process occupies the lower 32K. Since UZI currently barely fits in 32K, a full 64K of RAM is necessary. UZI does need some additional hardware support. First, there must be some sort of clock or timer that can provide a periodic interrupt. Also, the current implementation uses an additional real-time clock to get the time for file timestamps, etc. The current TTY driver assumes an interrupt-driven keyboard, which should exist on most systems. The distribution contains code for hard and floppy disk drivers, but since these were written for custom hardware, they are provided only as templates to write new ones. How UZI is different than real Unix: UZI implements almost all of the 7th Edition functionality. All file I/O, directories, mountable file systems, user and group IDs, pipes, and applicable device I/O are supported. Process control (fork(), execve(), signal(), kill(), pause(), alarm(), and wait()) are fully supported. The number of processes is limited only by the swap space available. As mentioned above, UZI implements Unix well enough to run the Bourne shell in its full functionality. The only changes made to the shell's source code were to satisfy the limitations of the C compiler. Here is a (possibly incomplete) list of missing features and limitations: The debugger- and profiler-related system calls do not exist. The old 6th edition seek() was implemented, instead of lseek(). The supplied TTY driver is bare-bones. It supports only one port, and most IOCTLs are not supported. Inode numbers are only 16-bit, so filesystems are 32 Meg or less. File dates are not in the standard format. Instead they look like those used by MS-DOS. The 4.2BSD execve() was implemented. Additional flavors of exec() are supported by the library. The format of the device driver switch table is unlike that of the 7th Edition. The necessary semaphores and locking mechanisms to implement reentrant disk I/O are not there. This would make it harder to implement interrupt-driven disk I/O without busy-waiting. [...etc...] alan -- ------------- Alan Strassberg alan@lmsc.lockheed.com (408) 425-6139 Lockheed, Santa Cruz, California. From leroy@netcom.com Sun Mar 3 13:49:04 CST 1996 Article: 134976 of alt.folklore.computers Xref: uchinews alt.folklore.computers:134976 rec.games.computer.quake.misc:6567 Newsgroups: rec.games.computer.quake.misc,alt.folklore.computers Path: uchinews!condor.acc.iit.edu!chi-news.cic.net!nntp.coast.net!lll-winken.llnl.gov!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!ix.netcom.com!netcom.com!leroy From: leroy@netcom.com (W. LeRoy (AKA MrWizard) Davis) Subject: Re: Quake on the Commodore 64! Message-ID: Followup-To: rec.games.computer.quake.misc,alt.folklore.computers Organization: NETCOM On-line Communication Services (408 261-4700 guest) X-Newsreader: TIN [version 1.2 PL1] References: <4h4v6n$jk3@news.cais.com> <4h695v$frg@madeline.INS.CWRU.Edu> <4h7l9q$f5i@hermes.acs.unt.edu> <4h7tt1$jjr@newsstand.cit.cornell.edu> Date: Sun, 3 Mar 1996 05:32:20 GMT Lines: 23 Sender: leroy@netcom7.netcom.com Status: RO Mike Puterbaugh (mbp8@cornell.edu) wrote: : Hasn't this "awesome piece of software runs on my abacus" joke been : hashed over enough yet? Not wanting to perpetuate a joke, but wanting to keep a clear mind -- There *is* a port of UNIX to the C-128 (slim as it might be...) and there is a operating system called LUnix (Little Unix) that runs on a network of up to six C-64's... I've seen GigaByte SCSI drives, 28.8k modems and now 20Mhz accelerators for the C-64. Just because W-95 requires 4+ Meg of memory to run does not mean that GUI operating systems need that much. GEOS for the C-64 is a GUI that runs in less than 64K. There are reasonable limits to what can be done on small systems, but we need to keep an open mind... -- W. LeRoy Davis leroy@netcom.com or leroy@calweb.com or "Hey You!!!" ----------------------------------------------------------------------------- Don't ever think you know what's right for the other guy. Paul Williams He might start thinking he knows what's right for you. "Das Energi" From uchinews!vixen.cso.uiuc.edu!uwm.edu!cs.utexas.edu!uunet!munnari.oz.au!newshost.anu.edu.au!sserve!cserve.cs.adfa.oz.au!wkt Thu Aug 5 11:03:01 CDT 1993 Article: 45780 of alt.folklore.computers Newsgroups: alt.folklore.computers Path: uchinews!vixen.cso.uiuc.edu!uwm.edu!cs.utexas.edu!uunet!munnari.oz.au!newshost.anu.edu.au!sserve!cserve.cs.adfa.oz.au!wkt From: wkt@cserve.cs.adfa.oz.au (Warren Toomey) Subject: Re: Really small UNIX boxen Message-ID: <1993Aug5.031300.5217@sserve.cc.adfa.oz.au> Sender: news@sserve.cc.adfa.oz.au Organization: Australian Defence Force Academy References: <1993Aug5.005950.17799@monu6.cc.monash.edu.au> Date: Thu, 5 Aug 1993 03:13:00 GMT Lines: 30 Status: R In article <1993Aug5.005950.17799@monu6.cc.monash.edu.au>, ins559n@aurora.cc.monash.edu.au (Andrew Bulhak) writes: |> I have heard a while ago that someone got some sort of UNIX-like operating |> system to run on an Apple II. Has anyone else heard this? I rewrote Xinu for the Apple ][, in 6502 assembly code, just for fun. It was so quirky: - context switching involved saving/loading registers, the zero page and the stack -- very slow. - the Apple ][ didn't have a hardware clock. I built up one and used the IRQ line to prompt the OS. - all disk I/O _had_ to be done in software with timed loops. The system lost time during disk I/O. - all processes had to be written in posn-indep code; the 6502 doesn't have any memory hardware. - the shell and some builtins (like ls) were built into the OS (shareable). - I used ProDOS' disk structure as it was hierachial, not flat like DOS 3.3. I tried getting the Uni to allow this to be my Honour's project, but they turned me down. Oh well...... Warren Toomey wkt@csadfa.cs.adfa.oz.au