From: thad@public.BTR.COM (Thaddeus P. Floryan)
Newsgroups: comp.sys.m68k
Subject: Re: speeding up an '020 system
Date: 12 Apr 92 04:43:00 GMT
Organization: BTR Public Access UNIX, Mountain View CA

In article <ku6qg0INN7ud@exodus.Eng.Sun.COM> wdorsey@lila.Eng.Sun.COM (William Dorsey) writes:
>I have a couple of ideas on improving the performance of an old Sun 3/60
>[...]
>The 3/60 contains an 68020 clocked at 20MHZ.  It works with 100ns simms,
>though it presently has 80ns simms installed in it.  If the '020, '881,
>and other chips in it could handle a higher CPU clock speed, this would
>be one way to speed things up.  I'm thinking of trying a 50MHZ crystal
>which would bring the clock rate up to 25MHZ.
>
>Another idea I have is building a daughter board with an '030 on it and
>then performing the necessary translation to mimmick an '020.  My own
>benchmarks seem to indicate the '030 is roughly 40% faster than that
>'020 at a given clock speed.  I could even combine this idea with the
>above idea and put in an '030 and run it at 25MHZ.  I know the '030 is
>missing a couple of instructions found on the '020, so I may run into
>problems with this approach.  However, the Sun 3E systems used '030s in
>them and I suspect the OS will still work.  Anyone heard of a company
>that sells daughterboards like this for upgrade purposes?
>[...]


I, too, have a buncha 3/60 systems.

I really cannot fault their performance.

But, in keeping with your posting, here are my thoughts.

First, the SINGLE most important thing to speed up the 3/60 is to add as much
RAM as you can afford.  The SIMMs really aren't all that expensive, with each
1MB SIMM around $37 even at consumer-type stores, brand new with warranty.  To
max it out with 24MB isn't that costly.

The SECOND most important thing is to get a fast HD.  The two fastest (and
affordable) disks I could find on the market are the Quantum 425S and the
Fujitsu 520MB; both are 3-1/2" and 9mS avg access time.  Believe me: these
made the systems operate like greased lightning, much faster than the 380MB
Micropolis or even the 1GB HP-97549 drives.  And you can put a bunch of them
in the shoebox to reduce your system's overall "footprint".

Now, as for upping the clock rate, you're going to be on your own.  Without
the system schematics, I cannot offer suggestions as to what to look at in
terms of trouble-spots. There are a LOT of different "glue" chips on the
motherboard and who knows what does what.  You might wish to post to the
comp.sys.sun.hardware newsgroup since there are a lot of hardware hackers
hanging out there.

As for daughterboards, now that becomes feasible, since there are a number
of companies who make such things for Motorola-based systems.  The oldest
is CSA (Computer System Associates) in San Diego CA who was originally
contracted by Motorola to upgrade Motorola's MC68000 trainers to become
MC68020 trainers; their daughterboard plugs into the MC68000 slot.

Since then (circa 1984), they and many other companies mfg similar types
of cards for Amigas, Macs, etc. for just that purpose, so, given clearance
under the hood, it "should" be possible to slap an '030 or '040 card into
the 3/60.

HOWEVER: you may run into kernel problems with stack frames, methods of
enabling/disabling data/instruction caches, MMU inter-operability, etc.
Remember that Sun has "application" and "architecture" compatibility issues.

For "applications", normal programs work just fine across the board.

For "architectures", Sun has DIFFERENT kernels for the '020 and '030.  They
clearly spell out these issues in the SunOS documentation set.

Given that Sun has essentially abandoned their Motorola-based line, you may
encounter problems securing a kernel for an '030 system (i.e. Sun 3/80).

My suggestion would be to keep the 3/60, and get an H-P, UNISYS/Convergent,
or Amiga '040-based UNIX system if performance is really that much of an issue.

Thad Floryan [ thad@btr.com (OR) {decwrl, mips, fernwood}!btr!thad ]
Newsgroups: comp.sys.m68k