In a message dated 4/9/00 13:16:27 Central Daylight Time,
ard(a)p850ug1.demon.co.uk writes:
> As I understand it, an H?? is a Heathkit, and came in kit form. Actually,
> the CPU and terminal logic boards were factory assembled/tested, and you
> only got to assembly the PSU, video board and case :-(. The Z?? is a
> Zenith, and came assembled.
You also got to assemble the Serial card and the HS Floppy controller.
Mike Stover, KB9VU
CCA# 404
CRA# 77
MARS AFA3BO
Florissant, MO
On Apr 9, 14:32, Technoid(a)cheta.net wrote:
> Now my last and only problem is that BOTH of my sun keyboards (type 4)
> work well but BOTH of my optical mice have one led that DON'T LIGHT.
> Working on this one. Also I don't have a mousepad but I think I can
> construct one while I wait to find one.
Are you sure about that? One of the LEDs is an infrared LED, with no
output in the visible range.
> I have had difficulties locating pinouts and other tech info on the
mouse.
> Any suggestions?
ftp://ftp.ececs.uc.edu/pub/sun-faq/Docs/FixingASunMouse
Also worth a look is the section on converting a Sun optical mouse to an
SGI mouse, in
http://www.geocities.com/SiliconValley/Pines/2258/4dfaq.html
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
In a message dated 4/9/00 16:55:02 Central Daylight Time,
allisonp(a)world.std.com writes:
> >All H-89's were sold in kit form. The H-88 is another story. These were
> >early all in one computers and did have 8080 CPU's in the beginning. Most
> >H-88 units were upgrades to the H-19 terminals.
>
>
> Wrong! the H88 was the diskless version of the h89 and was z80. The h8x
> were all z80. The basic design was H19 terminal with an additional Z80
> based card (with peripherals on ad in cards).
>
>
> All of the H/Z series are related and part of the changes reflects Heath to
> Zenith transistion. The 88/89/90 were the same base machine with different
> features namely different memory configs and disk subsystems.
>
> Allison
>
>
Yep, I misspoke. Thinking H-8 and talking H-88. Thanks for the correction.
Mike Stover, KB9VU
>DEC ended up dumping some of their early micros on their own employees.
>The used market was flooded with VT180s and PDT-11/150s for a while there,
>as a result. But presumably the employees got special pricing, so it's
>probably not fair to count them as real live sales to private individuals,
>since they had special incentives.
They were initally available with incentives, later they were cheap at end
of product and then when internal use was phased out then were retired
and often given away. Got my my systems by the later means while there.
Allison
Richard Erlacher said,
>The conventional wisdom where NASA is concerned, is that they HAD high
>standards through the Apollo program and that shortly thereafter, a lot of
>people left and apparently took vital talents with them. I've not worked
>directly with NASA people in a very long time, and can't agree or disagree
>with that view.
I'm working at NASA right this very minute. I think it's pretty much
impossible to categorize "NASA" as a single monolithic coding entity. Here
at GSFC, there's one group running the ground system that is very
conscientious and writes good code, with input checks, comments, version
control, descriptive variable names, etc., and properly tests the code
before running it for real. Then there's another group where their
acceptance test run of the code (which I observed) gave a list of internal
tests, all saying "passed". But when I asked exactly what each test did, it
turned out that *half* of them did nothing other than print up the word
"passed". This was flight code, btw, and they had not told us of any plans
to upgrade it. It's better now, and fortunately is not critical to the
mission in any case. But the bottom line is that even within a single NASA
field center, there's a *lot* of variation.
- Mark
>Yes, KO thought the DEC product line should be marketed to professionals.
>However, at the time, the people to whom a computer product had to be
>marketed was the hobbyists. It had been amply demonstrated that, no matter
>how marginally it fit, the personal computer as marketed to hobbyists would
>"do" in place of the supermini, with the trend toward distributed
processing
PCs were useful in that they were local and flexible. reliability was hard
to
come by with them.
>spreading wildly, while no one could replace the 1000 or so PC's that cost
>what a supermini cost with a supermini. Professionals were, themselves,
True, by '87 the price/perfomance crossover for the individual user
was comming around.
>facility where my neighbor works. Their Pro-380 didn't do so well next to
>PC's costing less than half what they did. The high cost of DEC software
>licenses didn't help either.
By time the Pro380 hit, it was too late. Still it had things that PCs were
trying to do often not well. The license issue was costly but we are paying
for the alternative still.
>About 15 years ago, I was put in the position of demonstrating that a
>cluster of '386 PC's would outperform a custer of microVAXen in a given
>environment. What brought down the house was by how much they outdid them.
I did the same thing using z80s. What the vax did better was network, do
general applications and groupware. It was (even as a cluster) and still is
far easier to manage than 40 W95 PCs and 3 NTservers! I never achieved
the generalized performance of a vax even with multiple z80s.
>I was not nearly as sure of myself about that comparison as I had been in
>the previous SCSI/ESDI comparison. In fact, because of the substantially
>more efficient use of mass storage in the DEC MSCP, I expected that the
PC's
>would be I/O bound to their single hard drive, while the uVAX with a drive
>pair could operate much faster. There's quite a difference between what
>they can do and what they will do, I guess.
I found I could bring a PC to it's knees IO wise faster than a loaded vax
and
when the PC folded it wasn't graceful... still isn't under MS anything.
On the otherhand I've tuned vaxen and there are tricks that PCs still
haven't
learned. Try running multiple MSPC and mutiple SCSI controllers say two
of each with one spindle per... then Qbus is the limiting element. PCs
of the era of Qbus were ISA16 and they could never stand two EDSI and
two SCSI controlled in the same box, assuming you could get Win3.1
to even install them. Of course the 8-10 mhz bus was the bottleneck and
the controllers were not smart at all if they even had DMA.
Reminds me of the guy at citicorp in 1990 telling me his 386dx/33 could
crush the VAX750 (no racehorse). I wasn't impressed. He stopped making
the claim of superiority when I asked when the last reboot was due to a
crash.
Seems the vax was an unattended server with 1yr 3months uptime and was
also used to serve out his local PC database.
Comparisons are like many thing statisical... mostly point reference.
Allison
My $02 on PCs is Linux/FreeBSD/netbsd was the best thing to happen to
PC hardware as it was the first OS with some semblence of performance
and concept of operational stability.
If there is anything worng with PC vs VAX comparison is often the vax
compared
is nowhere near bleeding edge and the PC is. Then again the VAXs in
question
had more uptime than the PCs time in production. Also the VAX (running
any
OS of choice) had better IO buffering than most very highend PCs until the
early 90s.
On April 9, Technoid(a)cheta.net wrote:
> My sun mice only have one led lit per mouse. There should be two lit as
> there is obviously a second led that is not. Any suggestions on repair or
> replacement of the mouse. The box is perfect! --
It's normal to see only one LED lit...the other is infrared...
-Dave McGuire
In a message dated 2/6/00 15:25:49 Central Standard Time, west(a)tseinc.com
writes:
> > Mike
> Thanks for the tip!
>
> Hey, I haven't got a chance to go through the stuff yet. Tell me, are these
> H89/90's or Z89/90's?? Isn't the different an 8080cpu vs. Z80?
>
Just found this note Jay. All H-89's and Z-89's have the Z80 processor
installed. The H-8 computers came with the 8080 installed. The Early H-89's
had an ORG 0 problem with CP/M but none of yours have that problem ... they
have all be modified.
The Z-90 series came with the soft sector card installed from the factory.
All H-89's were sold in kit form. The H-88 is another story. These were
early all in one computers and did have 8080 CPU's in the beginning. Most
H-88 units were upgrades to the H-19 terminals.
How are you coming with your treasure trove of old H/Z stuff? I did find
some more software and a few other spare parts. They are here whenever you
holler.
Mike Stover, KB9VU
CCA# 404
CRA# 77
MARS AFA3BO
Florissant, MO
On April 9, Charles P. Hobbs (SoCalTip) wrote:
> Sort of speaking of which: did anyone ever buy any DEC equipment for home
> use (Not VAXen and stuff, I'm more thinking about their PC's such as the
> Rainbow?)
When I was in my teens (1985 or so) I worked in a retail computer
store in a mall. We carried original IBM PCs, Apple clones made by
Franklin, Kaypros, and...DEC Rainbows & Pros.
I only saw a few of them sell...but they did sell.
-Dave McGuire
