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Path: utzoo!mnetor!seismo!uwvax!astroatc!johnw
From: johnw@astroatc.UUCP (John F. Wardale)
Newsgroups: comp.arch
Subject: Re: Cost of Designing a New Computer (Software)
Message-ID: <673@astroatc.UUCP>
Date: Mon, 5-Jan-87 15:22:33 EST
Article-I.D.: astroatc.673
Posted: Mon Jan  5 15:22:33 1987
Date-Received: Mon, 5-Jan-87 22:06:46 EST
References: <950@husc6.UUCP> <666@instable.UUCP>
Reply-To: johnw@astroatc.UUCP (John F. Wardale)
Organization: Astronautics Technology Cntr, Madison, WI
Lines: 31
Keywords: hw, sw, micros, super-minis, unix
Summary: big machines get more sw

In article <666@instable.UUCP> amos%nsta@nsc.com (Amos Shapir) writes:
>In article <950@husc6.UUCP> reiter@harvard.UUCP (Ehud Reiter) writes:
>>Port UNIX to new supermini	-    1's of engineer man-years
>>New micro system software	-  100's of engineer man-years
>>New supermini system software	- 1000's of engineer man-years
>>New mainframe system software	- 1000's of engineer man-years
>
>You must be a hw engineer :-)  There's no reason that mini or mainframe
>software would be an order of magnitude bigger than micro sw.
>...
>it's not the size of the hw, but the functionality that determines 
>the effort required;

You must be an applications programmer :-)  Operating system
issuses like performace, VM, and most importantly periferal
support are greater for bigger machines.  It takes losts more
system software for a large Gould/Pyramid/Vax etc. than it does
for an XT/AT etc. running Zenix.  
The point is that sw for micros is commonly much smaller (lower
grade??) than for bigger systems because smaller systems usually
have (can only afford) fewer functional requirements.

>UNIX was written by 2 men over 2 years, and ...
And has had 10K to 1M man-years of developments since them, which
brings me to my second point:
Doing a full port of unix to new hw (with different VM support,
multiple periferal choices, and a complex I/O sub-system) is more 
like 10's of man-years (especially if you add a few performace 
hacks to tune it to your machine, and then do a bsd 4.x and
System V support, or dual universe).
--> Anyone know how long it took Cray to put unix on the Cray-2?