Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!nosc!ucsd!ucbvax!hplabs!hpda!hpcupt1!kluft
From: kluft@hpcupt1.HP.COM (Ian Kluft)
Newsgroups: comp.arch
Subject: Re: HP2100 (was: Re: Self Modifying Code)
Message-ID: <6310010@hpcupt1.HP.COM>
Date: 20 Jul 88 22:54:42 GMT
References: <33895@yale-celray.yale.UUCP>
Organization: HP Systems Technology Div, Cupertino CA
Lines: 64

First a note: this is not a flame.  (I don't flame if I can avoid it.)
This message is additional information on the subject from a different
point of view.

The HP2100 became the HP1000 probably at least 10 years ago.  The E- and F-
series 1000's retained model numbers starting with 21, such as 21MX.
I worked last Summer in HP1000 software support and got to see how the
support works.  I also took a class on Micorprogramming at CSU Chico this
past Spring in which we used an HP1000E 21MX (of 1978 vintage).

Anyway, the HP2100 software still runs on the 1000 as-is.  But the 1000 was
redesigned into the A-series in the mid 80's in order to maintain a lead
in the real-time systems market.

I'm not trying to be defensive of a system that, at the time, earned the
comments Bjorn gave.  It just sounded like he wanted to see improvement.
Below are some places where what he wanted has been done.

lisper-bjorn@CS.YALE.EDU (Bjorn Lisper) writes:
> * It did have time-sharing, but the memory was statically partitioned and
>   the only way to change the partitioning was to generate a new copy of the
>   operating system!
>
> * Max address space for a program 64K. No virtual memory, so if you needed
>   more then explicit segmentation with code overloading was the only way to
>   go.
RTE-A (Real Time Executive, A-series) has multitasking, multiuser, and virtual
memory.  Yes, things have changed.

> * Dumb terminal drivers that didn't recognize ^S & ^Q, not to mention the
>   nifty block transfer protocols their own 264x series terminals were
>   capable of (which, amongst other things, made these terminals' function
>   keys useless).
My project last Summer was to work on additional docs for the multiplexer
(8-port serial board).  The dumb-terminal drivers are only included now
for backward compatibility.  The newer drivers have enough features
that my "supplementary" documentation grew to 70 pages (including
illustrations).

> * A contiguous-storage oriented file system that frequently lead to
>   disk space fragmentation problems. Whenever that happened you had to
>   switch to single-user mode and run a disk compaction program...
That sounds pretty familiar.  I remember the disk compaction program but
I didn't have fragmentation problems.  I can't say for sure what, if anything,
has changed in this area.

They've made it look more like Unix in this respect.  It has a heirarchical
file system with a Unix-style shell.  (If you're used to Unix, though, don't
expect it to be identical.  It's nice compared to the old FMGR but Unix gurus
would be disappointed.)

> [...] A not too unusual comment after a bug report was: "this
> bug will not be fixed"! I guess HP didn't put in too much manpower into
> supporting this system. I also guess that they were right in not doing so...
I can think of a few circumstances where they might not want to fix something
that will take forever to repair when a workaround is available.  The main
point here is that those people do care (I know, I worked with them) - they
just have finite resourses, like the rest of us.  However, they do have
adequate manpower for most problems.

------------------------------------------------------------------
    Ian Kluft			RAS Lab
    UUCP: hplabs!hprasor!kluft	HP Systems Technology Division
    ARPA: kluft@hpda.hp.com	Cupertino, CA
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