• Please review our updated Terms and Rules here

Unix on a Z80 machine

Try not to take such delight in turning things personal.
Delight??? More like mild annoyance; it's not the first time that I've posted a reply to a question only to have you contradict me with what I consider a misleading and perhaps even ill-informed generalization, invariably leading to a defensive counter-reply, etc. etc...
My "arbitrary" criteria came from the chapter headlines from the book "The Design of the Unix Operating System" by Maurice Bach. Is that too arbitrary for you?
I suppose we could argue that your choice of that book and the particular criteria you chose are arbitrary, but it doesn't really matter since we're not only talking about true-blue AT&T/IEEE-sanctioned UNIX but also UNIX derivatives.
I understand the memory is bank switched. How is kernel mode vs. user mode enforced?
I don't understand the question?
 
I'm fairly certain the definitive qualification of whether something is 'UNIX' is whether the producer of said material has ever had "SCO vs <their name>" read from a federal circuit court docket.
 
I should add that there was a massive rush toward Unix ports when the 68000 came out, particularly after SysV came out, although there were plenty of BSD-based ventures as well.
Yeah, Cromemco made SysV available as well when it came out (but not for the Z80 systems ;-) )
And MikeS has a point--why would anyone want to do this, given that the product base for the Z80 was pretty much exclusively CP/M?
Indeed; but much of Cromemco's user base was in universities, research and government, where being able to still run familiar CP/M apps like dBase, SuperCalc and Wordstar in a Unix-like environment while concurrently doing the 'real' work in Fortran, C or even Cobol was a big selling point.
 
Minix and Xinu had many of the elements of Unix. I believe both were at one time running on Z80's?
 
Exactly. Basic computability theory. Given enough storage and a Turing-complete instruction set, any CPU can emulate any other CPU...

I had a dream about emulating x86-64 on a Z80, and running Windows 7 on that. Then I woke up screaming and babbling incoherently. It took many years of therapy to get back what sanity I now have...
 
I just wrote a quick UNIX web server running on my ZX-81 Sinclair (with extra 16K RAM cart) attached to the Internet through a IPV6 connection using the keyboard interface ribbon:

There are no graphics, just a prompt. Works best with Firefox.

http://207.245.109.38
 
If you get stuck hit tab until the prompt is responsive. Note that this is a farse...It's just my dos prompt style sheet.
 
Last edited:
I had a dream about emulating x86-64 on a Z80, and running Windows 7 on that. Then I woke up screaming and babbling incoherently. It took many years of therapy to get back what sanity I now have...
Apparently Windows 8 will run a lot better........................Hic!!
 
Why making a joke about this? I can fully understand why someone would like an operating system environment that resembles Unix, even if it is not 100% UNIX compatible when it comes to underlying structures and features. We already had at least three examples of somewhat Unix derivated systems running on Z80 computers. While neither of those might compare to a 21th century UNIX implementation (I'm not sure which implementations still exist, but that is a different matter), I don't think the original posters intention was to get a Z80 computer as his main workstation, file server, web server, number crunching server or whatever else one would use a Unix-like system for.

Clearly some of you put too much importance on that something needs to be fully compliant in order to be even remotely alike. From a legal standpoint, I agree that SCO, AT&T or whoever today administrates the rights to the UNIX trademark would not be amused if someone would distribute an unlicensed system involving UNIX as part of the name, in particular not if it does not fully comform to what sysadmins and users expect from a UNIX system. However as I indicate above, I think there is room for other interpretations what one would be looking for in a Z80 operating system that is not CP/M, Basic or Forth.
 
However as I indicate above, I think there is room for other interpretations what one would be looking for in a Z80 operating system that is not CP/M, Basic or Forth.

Some good points, but again, I say, "Exactly what of Unix makes an OS Unix?". That's really what needs to be qualified here. I count multi-user (with accounting), multi-programming with pipes, long file names, hierarchical filesystem, user privilege protection and the utility set as essential characteristics.

Remember that when MS-DOS 2.0 came out, Microsoft's stated objective was to evolve DOS to be indistinguishable from Xenix. It never happened, even though some Xenix-like features were added to DOS.
 
Why making a joke about this? I can fully understand why someone would like an operating system environment that resembles Unix, even if it is not 100% UNIX compatible when it comes to underlying structures and features.
Actually the other way around made a lot of sense to me; Cromix had most of the underlying structure of UNIX (inodes, pipes, lfns, all the stuff that Chuck mentions), but the environment was much friendlier IMHO with native commands like "ty[pe]", "help" etc.
 
In this small world of opinionated geeks there'll never be agreement on the definition of anything ;-)

As to the OP's question, were UNIX or derivatives 'ported' to the Z80?

True officially sanctioned UNIX? No.
UNIX more-or-less look-alikes and work-alikes? Yes, several.
 
In this small world of opinionated geeks there'll never be agreement on the definition of anything ;-)

As to the OP's question, were UNIX or derivatives 'ported' to the Z80?

True officially sanctioned UNIX? No.
UNIX more-or-less look-alikes and work-alikes? Yes, several.

Were those really 'ports? Or were they newly-written work/look-alikes? In other words, did someone actually take the code from Unix for ls and recompile it? Or did they write something that looks something like ls?

So the answer probably would be "no" there were no Unix 'ports.
 
Were those really 'ports? Or were they newly-written work/look-alikes? In other words, did someone actually take the code from Unix for ls and recompile it? Or did they write something that looks something like ls?

So the answer probably would be "no" there were no Unix 'ports.
I knew it! ;-) We can't even agree on the meaning of " 'porting' a derivative" , with 'porting' specifically in quotes on the assumption that the OP's meaning included look-alike & work-alike versions built on the concepts of UNIX, not specifically the code
 
Perhaps we need a Turing test for Unix-ness. :)
Submitted for your approval: "If your boot process contains shell scripts called from other shell scripts to a minimum nesting depth of five, it's Unix."
Alternatively, the criteria could be something about applications constructed out of other programs piped together.
 
Back
Top