Unix for 8080/Z80? [Re: WooHoo!! PC/XT Unix anyone?] - test-drb@ccmp.vtda.org

23 Jan 1999

This notion of cooking up or breathing new life into an old 8-bit model to
run *NIX is probably a mite more than has been considered for one reason. 
*NIX tends to want to use virtual memory, without which many systems would
quickly choke.  The old CPM-capables don't support VM.  A good reason for
this is probably the lack of performance.  

regards,

Dick

----------
...
  From: Tony Duell &lt;ard(a)p850ug1.demon.co.uk&gt;
 To: Discussion re-collecting of classic computers
&lt;classiccmp(a)u.washington.edu&gt;
...
  Subject: Re: Unix for 8080/Z80? [Re: WooHoo!! PC/XT
Unix anyone?]
 Date: Saturday, January 23, 1999 11:44 AM

 > Any Unix clones for 8080/Z80 systems? It ought to be doable, given that the
...
   original Unix
was done on a 64KB address space machine...  
 The problem with any multi-tasking or multi-user system on a Z80 is that 
 there is no easy way to write position-independant code. There is no 
 relative call and no relative loads/stores (both the PDP11 and the 6809 
 have them). There are workarounds (either you use RST instructions to 
 simulate the relative call, etc or you relocate the task when you load 
 it), but they make life a little harder.

 -tony 