[comp.os.misc] questions on coherent

asgad@acad2.anc.alaska.edu (08/31/90)

From: asgad@alaska (george dowding)
Subject: Coherent

I am thinking of purchasing the coherent operating system.  It claims to be an
independently created UNIX clone.  Its supposed to be just like unix (minus
the cost).  Furthermore it will work under minimal conditions (IBM AT w/640k)

Has anyone tried this system?  If so, is it all that it is cracked up to be?

mrm@sceard.Sceard.COM (M.R.Murphy) (08/31/90)

In article <1990Aug30.130037.14@acad2.anc.alaska.edu> asgad@acad2.anc.alaska.edu writes:
>From: asgad@alaska (george dowding)
>Subject: Coherent
>
>I am thinking of purchasing the coherent operating system.  It claims to be an
>independently created UNIX clone.  Its supposed to be just like unix (minus
>the cost).  Furthermore it will work under minimal conditions (IBM AT w/640k)
>
>Has anyone tried this system?  If so, is it all that it is cracked up to be?

Coherent is more than it is cracked up to be :-)

  1) The manual is really quite good. Worth the price by itself. The lexicon
     section is quite good.
  2) Coherent is very close to V7 Unix(tm) on a PDP-11(tm). Better in that
     it will generally be running on a machine with more memory than a PDP-11
     was likely to have(248Kb). 640K is fine on an AT. 1MB is better. Also,
     the AT (maybe tm, who knows for sure?) is probably going to be faster
     as a CPU (certainly faster than an 11/23 :-).
  3) Coherent has lots of space available with a 40MB disk partitioned as
     10MB for root, 30MB for a user filesystem. A 20MB disk would be ok. Really
     big disks, they haven't thought about so much, it seems. I'll run out
     of space on the 40MB when Cnews works.
  4) The C compiler is good.
  5) The object libraries are good, with the caveat that there are always
     routines in some other Unix that are used in a program that aren't in
     whatever Unix you happen to be using. You know, Coherent doesn't have
     wait3 or sigsetblock or sysgetfarknargle... Porting is about the same
     trouble as BSD(tm) to SysV(tm).
  6) It has online man pages. Enough said.
  7) The mail reader is marginal.
  8) UUCP is ok, but not real spiffy. Works, but minor warts are annoying.
  9) The distribiution is probably the best I've seen. Careful attention to
     permissions, that sort of thing. Considering that it is supposed to run
     on lots of manufacturers little tan boxes, that's amazing. It's certainly
     easier to install than V7 :-) Only 4 diskettes to feed into the machine.
 10) No f77.
 11) No DWB (nroff,troff,...)
 12) No WWB (style,dict,...)
 13) Good FPU simulation if you don't have an '87 equivalent
 14) Currently limited to 32MB disk partitions.
 15) A really good device driver installation kit.
 16) Small model only. Same as a PDP-11. No 16MB programs here. But microEmacs
     is supplied, and works. Fast.
 17) Elvis (vi clone) works. Fast.
 18) Disk I/O is about 4 times faster than 1.3 Minix(tm, maybe?) On the same
     platform.
 19) What do I know about the myriad of VGA, EGA, PGA, CGA, EVGA, HMG, ...
     if it doesn't work, send it back and get your money back. They have
     some sort of a guarantee.

I think it's well worth $100 or so.

A satisfied tinkerer, thinking of using Coherent in a product, not affiliated
in any way with MWC, and all of the above is opinion. Disclaimed enough?
BTW, all this (tm) stuff is a pain in the tail. Who gives a tinker's dam.
-- 
Mike Murphy  Sceard Systems, Inc.  544 South Pacific St. San Marcos, CA  92069
mrm@Sceard.COM        {hp-sdd,nosc,ucsd,uunet}!sceard!mrm      +1 619 471 0655

royce@scor_az.resp-sci.arizona.edu (Royce Robbins) (09/03/90)

Haven't gotten to look it over that closely, but yes, the manual is GREAT!  
Beats the Docs that come with SunOS all over the place.

Biggest minus I see is that you are limited to a Bourne shell (no C shell) and
there does not appear to be ANY support for networked support, not telnet, ftp,
or any other TCP/UDP/IP applications.  Appears to be strictly a serial-line
network via KERMIT (included) or UUCP.  Bummer.

						--Royce Robbins
						Div REsp Sciences
						UofArizona

lshao@nation.ics.uci.edu (Ling Shao) (09/07/90)

In <1990Aug30.130037.14@acad2.anc.alaska.edu> asgad@acad2.anc.alaska.edu writes:

>From: asgad@alaska (george dowding)
>Subject: Coherent

>I am thinking of purchasing the coherent operating system.  It claims to be an
>independently created UNIX clone.  Its supposed to be just like unix (minus
>the cost).  Furthermore it will work under minimal conditions (IBM AT w/640k)

>Has anyone tried this system?  If so, is it all that it is cracked up to be?

I have been trying out the Coherent OS for almost a month so I guess maybe I
could give you some ideas about this OS.

Mark Williams Company is correct when it claims that it is a multi-user,
multi-tasking operating system. It does provide the most rudimentary "Unix"
functions and it comes with some pretty nice utilities. In my observation,
Coherent appears to be in the class of Unix Version 7 OS. Mark Williams
has been real careful in avoiding to use theord Unix in its documentation.
In fact, I think I could not find more than 10 sentences that contain the
word "Unix". There is no explicit documentation to state its level of
compatibility with the "real" Unix.

So far, everything ses to work. However, I haven't really dug into the
C compiler and try to write out some programs so I don't know how source
compatible Coherent is. By looking at the library header files, it looks
compatible (to version 7).

If you are planning to get this system, don't expect anything fancy out
from it. After all, it is a $99 OS which is even cheaper than MS-DOS.
The OS comes with the basic Bourne Shell (no Csh or Tcsh unfortunately).
It does come with emacs, yacc, lex ... There is the basic Unix email system
but no fancy stuff like mh_mail. About the performance, I wouldn't say it
is exceptionally fast (I am running it on a 10MHz AT Compatible) but the
speed is certainly reasonable. The time when the system really slows down
is when there are more than 2 tasks accessing the harddisk at the same time.
If your foreground task is also accessing the hard disk, you might have
to wait for a while (~5 - 10 secs, depends on what you are doing). However,
the effect on a foreground task running completely in memory is minimal.
I think this is more of a problem for the ISA architecture rather than the
OS as ISA is not really designed for multi-user multi-tasking operation.

So, what do I really think? (i.e. Am I going to return it before the 60 days
trial period is over?) Well, it is kind of hard to say right now. First, I
brought this system just for hobby at home. This system is not good enough
to serve as a real production system (if you want the real stuff, get a Suns).
For hobby, I think it is perfect. However, I am also considering Minix right
now.

Minix does have some advantages over Coherent. First, Minix has been around
for longer and I presume it has a much larger installed base (the
comp.os.minix newsgroup has 26000 readers). Unlike Coherent, it does
support networking on ethernet (TCP/IP is not officially supported) and
it works on the Micro Channel based PS/2 after being patched. It is
constantly being maintained and upgraded by thousands of people across the
nation. Also, Minix runs on machines ranging from PCs to 386 to Atari ST.
In the coming years, it will also run on Mac and Amiga. The developer is
also making it to be more Posix compliant.

However, Minix does have at least one major limitation. Many utilities
(which I personally think are very important) are not provided in the
official release of Minix. Minix v.1.3 doesn't come with emacs, mail,
lex, yacc, and uucp. You might be able to get these stuff from independent
developers (since there are so many people working on Minix) but I don't
know how easy or reliable that is going to be. Minix V.1.5 should be
coming out by now or pretty soon and I certainly hope they will at least
provide emacs and uucp in the official release. The missing of some of
these utilities is a major problem for me. Even though I am using
Coherent for hobby, I do need at least an emacs editor so that I can
write programs (I can never use mode oriented editors like vi). I don't
mind having to write my own Csh but at least give me a good editor to use.

Chung Ng
Information and Computer Science Department
University of California, Irvine
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