It would be really cool if some one were able to scan and make available
this data sheet for those who are unable to find it.
<If anyone wants to get this data sheet, it's reprinted on page 605 of the
<'Student Manual for the Art of Electronics' by Thomas C Hayes and Paul
<Horowitz (2nd Edition, ISBN 0-521-37709-9)
- don
>>Sure, if the old stuff works, why change? (Even if it -is- obsolete!)
>>It does indeed make sense.
>I can honestly say that is where you and I differ greatly: the definition
>of "obsolete."
One of my all-time favorite .sig lines (I forget whose it was) said:
" Don't think of it as a `new' computer, think of it as `obsolete-ready' "
While collectors may argue about "obsolete" - a term, that to my ears,
smacks of PC-clone salesman-speak - in the world of business
and industrial computing, platforms that are old and well-established
are called "legacy systems". It's generally acknowledged that if a
system does its job well and reliably, it is "legacy"; the mark of a
non-legacy system is that it is under constant development, crashes often,
and doesn't fill its design specs.
Of course, here I'm talking about more than hardware, and more than
hardware+software, but how a system fits into the real world and performs
a useful function.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
<One of my all-time favorite .sig lines (I forget whose it was) said:
<
<" Don't think of it as a `new' computer, think of it as `obsolete-ready' "
To that I also add:
"Stable mature systems we know how to use."
Allison
>lemay(a)cs.umn.edu writes:
>> Well, it looks like the University of Minnesota is having another
>> beautiful U day... this is something the latest U president came up with
Just grab everything and anything that looks interesting.
You can always dispose of it later if its not.
Lance Costanzo | Speaker to Animals
lance(a)costanzo.net | speaker(a)kzin.com
http://www.webhighrise.com | http://www.kzin.com
Website and Virtual Domain | PC Resources,
Hosting starting at $5/month, | Accoutrements,
no setup fees | and other oddities.
In a message dated 10/25/99 9:32:34 PM US Eastern Standard Time,
lemay(a)cs.umn.edu writes:
> Well, it looks like the University of Minnesota is having another
> beautiful U day... this is something the latest U president came up with
> a few years ago, basically instead of departments on campus having to
> pay to dispose of old and obsolete equipment, on a Beautiful U day, they
> put out tons of bins all over campus, and the departments can toss in all
> the old computers and such they want, and the university will pay the
> disposal fees (as opposed to the individual departments paying).
>
> Anyways, this means there may be jems appearing soon. For example,
> I just saw a HP 85 out in the hallway, I assume someone is jumping
> the gun on cleaning their areas... Is anyone dieing to have a HP 85?
> is there anything else I should be looking for? In the past few years,
> I usualy have seen at least one Apple ][+, IBM PS/2's, etc.
>
sure would be nice to have all the memory simms out the PS/2s that get thrown
out... Unfortunately, they always seem to command a premium price. if you
can't grab entire machines, even cards or memory or even hard drives would be
worth getting.
Well, it looks like the University of Minnesota is having another
beautiful U day... this is something the latest U president came up with
a few years ago, basically instead of departments on campus having to
pay to dispose of old and obsolete equipment, on a Beautiful U day, they
put out tons of bins all over campus, and the departments can toss in all
the old computers and such they want, and the university will pay the
disposal fees (as opposed to the individual departments paying).
Anyways, this means there may be jems appearing soon. For example,
I just saw a HP 85 out in the hallway, I assume someone is jumping
the gun on cleaning their areas... Is anyone dieing to have a HP 85?
is there anything else I should be looking for? In the past few years,
I usualy have seen at least one Apple ][+, IBM PS/2's, etc.
Unfortunately, I'm severely strapped for space, so anything i grab, i would
have to dispose of fairly soon. Obviously, if i see anything extremely rare
i will grab it, but I dont know about stuff like the HP 85, or calculators,
etc. So, I guess i'll just have to see whats available, grab it, and
then post it to the list quickly. For those near the U of Minnesota
Minneapolis campus, beautiful U day is this Wednesday. I imagine the
como recycling lot will fill up with stuff very soon now (thats where
I found my PDP 8/e 2 weeks ago).
Anyways, just a heads up for those in or near minneapolis, and I guess an
offer to trade a HP 85 (i'll ask if they are tossing it tomorrow, i
already informed my janitor friends in that area that i want it).
-Lawrence LeMay
Rumor has it that Mike Cheponis may have mentioned these words:
>(And, of course, most 486dx2/66 machines used at least an EISA bus [2],
> running 32 bits at 8.33 MHz x two clock edges = 533 Mbits/sec.)
[snip]
>[2] Indispensable PC Hardware Book, 3rd edition, p. 552
[for reference inclusion]
"Most" 486DX2/66's used EISA??? What's your definition of most? That book
of yours has a rather skewed idea of what "most" means.
Now, most "Server" 486's did have EISA AFAIK, but the server machines were
an _extremely_ small portion of the total number of machines in the real
world. (I actually had use of a retired Dell 486DX266 EISA low-end server.
[Low-end being defined as: Adaptec 1542 ISA SCSI interface, non-ECC
memory...] )
Certainly a nice machine, but by no means the most feature-filled server
Dell produced at the time.
The company I worked for at the time had roughly 400-500 486's deployed,
with 75-100 being DX33 or faster. I think 3 machines there had EISA, and
were all servers - not for use as a single-user machine until replaced by a
faster server.
BTW, those machines worked fairly well servicing around 100 users, but only
10-15% were at their desks at any one time - the rest of the machines were
logged in but idle. Of course, with a 400 user 10Mbit (non-switched)
ethernet network & 4 of these servers (the 4th was a PCI P60), by the time
the servers started doing real work & were slowing down, ethernet
collisions pretty much ground everything to a halt.
Two more PCI P60 servers replaced the 3 EISA 486's, and my employer allowed
me to take one home to work on - to replace the 4Mbyte 386SX16 I was
running AutoCad 12 on - and doing renders. Let's just say that 486 was an
extreme improvement. ;-)
(Oh, and the servers were just file-sharing servers running Netware 3.11,
for reference...)
Again, just my $0.02 (CDN, this time) and not worth that...
Roger "Merch" Merchberger
--
Roger "Merch" Merchberger --- sysadmin, Iceberg Computers
Recycling is good, right??? Ok, so I'll recycle an old .sig.
If at first you don't succeed, nuclear warhead
disarmament should *not* be your first career choice.
What is a VXT 2000+? It has 18 meg or ram. It comes up with VXT V1.5 followed
by 08-00-2B-37-70-4A. The configuration indicates that it has 8 plane Low Res
4 Megpixel FB which I assume is the graphics configuration.
It originally came with a DEC VRC 16-HA Low emission monitor. My scrapper who
has this feels the monitor is worth $150. If anyone interested in this, with
or without the monitor, contact me directly.
He also got in a couple of MVIIs that are available. I will get the
configuration next week
Paxton.
Whoops, change that last URL I gave (for the VXT software) to
ftp://ftp.openvms.digital.com/vxt/
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
>What is a VXT 2000+?
It's an X-terminal.
> It has 18 meg or ram. It comes up with VXT V1.5 followed
>by 08-00-2B-37-70-4A. The configuration indicates that it has 8 plane Low Res
>4 Megpixel FB which I assume is the graphics configuration.
"08-00-2B-37-70-4A" is the hardware Ethernet address. The VXT 2000+
loads its software over the Ethernet at power on. To quote from the
VXT release notes:
VXT software is installed on a load host and downloaded
into the VXT 2000[+], VXT 2000, or VT1300 X terminal; the
VXT software license applies to the X terminal on which the
software is executed, not to the host CPUs in the network.
The release notes then go on to specify how to install the software on the
following different systems - I imagine other network-capable systems
are easily done as well:
o VXT Software on InfoServer Systems
o VXT Software on OpenVMS Systems
o VXT Software on DEC OSF/1 AXP Systems
o VXT Software on ULTRIX Systems
o VXT Software on SunOS Systems
o VXT Software on HP-UX Systems
o VXT Software on IBM AIX Systems
o VXT Software on SCO ODT Systems
The software installation kit now appears on the OpenVMS Freeware
CD-ROM set, and you can grab it over the net from:
ftp://openvms.digital.com/vxt/
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
On or about 07:56 PM 10/24/99 -0700, Mike Cheponis was caught in a dark
alley speaking these words:
>That's fascinating. Take obsolete hardware and architecture (vax), and
>keep them running! I guess I will never cease to be amazed at the weird
>things people do. Heck, I heard the other day that people are -still-
>running 1401 emulation mode under a VM/360 simulator on their modern h/w!
The last three places I worked for (or heard of thru the grapevine) were
running mostly System 36 RPG apps in emulation on their AS/400 hardware...
it's more common than you might think!
>> Its not the speed
>>of the individual bus, but its the number of busses.
>
>That's of course bull.....
You crack on others for stating things without backing up with actual
data... where's yours? My wife's box is a Pentium 100 running SCSI3Wide and
I did benchmarks (real-world... but don't have them handy) which showed
that box stomped a Pentium 166 / IDE. (Mind you, saying the IDE bus is
rather an oxymoron, as it's an extension of the ISA bus IIRC... :-)
The difference? The IDE bus is totally stupid (read: CPU controlled)
whereas the SCSI bus is very smart (read: 80Mhz RISC CPU controlled) - the
SCSI controller is offloading most of the CPU overhead.
Despite all this, the mouse driver on it right now sucks wind, and can lock
the entire machine for over 3 seconds... bad driver/bus design. That's
something the PC world will prolly never get rid of.
Tho I've never seen, touched, smelled a Vax, I've seen other DEC hardware
(yes, even a 3-CPU 486DX33) that use sub-controllers for all of their I/O,
and they handled lots of multiple users wonderfully, and if one I/O
controller goes south, the equipment is designed to continue with minimal
heartburn.
>>The more busses, the more parallelism and the less waiting.
>
>-IF- the speed of the busses is high enough!
And one bus cannot affect another bus...
>>One
>>fast bus works well until you want to do multiple things, and
>>then it quickly becomes a bottleneck.
>
>Excuse me? Could you please back up this assertion with data? After all,
>at -some- point, all these busses have to get their data into/out of the CPU,
>right? And -that- is a "bottleneck" for sure... (Sure, you can have
>channel-to-channel I/O, but most aps are not just shuffling bits.)
The busses don't *have* to route their data thru the CPU (erm... unless
it's the IDE bus...) if it's headed for memory - that's what DMA is for. A
good DMA setup (which the PC doesn't have) can offload even more work from
the host CPU, allowing it to do useful work instead of playing "data
traffic cop."
As always, YMMV, IMHO, and all that jazz,
Roger "Merch" Merchberger
=====
Roger "Merch" Merchberger -- zmerch(a)30below.com
SysAdmin - Iceberg Computers
===== Merch's Wild Wisdom of the Moment: =====
Sometimes you know, you just don't know sometimes, you know?
I haven't received anything from this list in the last week or so.
As far as I know, nothing changed on my end. I've tried to send
'subscribe' and 'which' commands to the listproc, but I get no
response. Did something change at U-Wash?
- John
-----Original Message-----
From: Lawrence LeMay <lemay(a)cs.umn.edu>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Monday, October 25, 1999 6:36 PM
Subject: Re: Help - Is there a paper tape BASIC for a PDP 8/S
>>
>> I am hoping to find BASIC (not FOCAL) for the PDP 8 line. I can't run
OS/8
>> so I am hoping to find a BASIC that will run on my 8/S in binary form.
>
>Why cant you run OS/8, just because of a lack of enough core memory?
4k core only.
#1) I have no disk.
#2) I did not think OS/8 was compatible with the Straight 8/ 8/s instruction
set incompatibilities.
If it is compatible then I will actively seek a DF32 and interface.
>
>-Lawrence LeMay
>
>>
>> A) Does this even exist?
>> B) Is it on the Web?
>>
>> Thanks, this 8/S is proving to be lots of fun.
>>
>> BTW: I just got this message on my PDP tonight:
>>
>> "Congratulations!! You have successfully loaded 'FOCAL' on a PDP 8/S
>> computer."
>>
>> Yippee!
>>
>> john
>>
>>
>
I am hoping to find BASIC (not FOCAL) for the PDP 8 line. I can't run OS/8
so I am hoping to find a BASIC that will run on my 8/S in binary form.
A) Does this even exist?
B) Is it on the Web?
Thanks, this 8/S is proving to be lots of fun.
BTW: I just got this message on my PDP tonight:
"Congratulations!! You have successfully loaded 'FOCAL' on a PDP 8/S
computer."
Yippee!
john
On Oct 25, 15:59, Bill Pechter wrote:
> Is my memory of the breakdown of the diags correct?
>
> +--> Diag software
> | +--> Second diag
> | |
> ZRQBC1
> | |
> | +-->Revision C patch level 1
> +--RQDX? disk controller (does the R stand for Rotating Memory Here?)
Very close. The first character is the processor type it's intended for,
the next two are the device mnemonic (not always the same as the mnemonics
used elsewhere, alas), then diagnostic "number" (you know what I mean :-))
and then revision and patch level, as you said.
I can't help with the specifics of most diagnostics (my microfiche set is
neither complete nor very accessible at the moment -- wasn't most of that
stuff on-line inside DEC once? What became of STARS and TIMA?) but you
might find the general stuff at
http://www.dunnington.u-net.com/public/XXDP.ps helpful (there's a .pdf
equivalent there too, thanks to the assistance of another list member).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Hello:
I saw a message from jeff.kaneko(a)juno.com where it appears he got some
docs on the CS/80 etc. protocol from you. I think this is the protocol
used by HP for its HP-IB disks. I suspect that this protocol uses a
block mode addressing that spans a variety of devices built and sold in
the 80's and early 90's, incl. some by Bering (an alternate source of
HP-compatible HP-IB storage products).
I am looking for the disk protocols and command set to see if I can talk
to these devices with a National Instruments (GP-IB) board in a PC
running NT with a driver written in a modern high-level language. I
suspect that the commands are device-independent, as these HP devices
worked with a broad scope of computers, with very little change in
configuration. Does this sound like the same docs you have? If so, may I
please get a copy of those docs? I think that they are the same that
Jeff got from you. I'm in the Seattle area (Redmond) and am willing to
pay for your trouble photocopying.
Please give me a call and we can talk. I suspect that some of HP's SCSI
protocols are similar in structure and would like any thoughts you have
on this.
Thanks,
Jerome Hodges
Strobe Data, Inc.
8405 165th Ave NE
Redmond, WA 98052-3913
Ph. 425-861-4940
Fax 425-861-4295
On Oct 24, 21:48, Marvin wrote:
> Richard Erlacher wrote:
> > Has any of you ever encountered an approach to this that could be
managed in
> > the home environment with equipment costing, nominally, less that a
k-buck
> > or two and achieving nominally 10-mil traces with 8-10 mil separation
or
> > anything close to that? How about a dry-film solder mask?
> Doing the process at home can be done with a minimum of equipment if
service
> shops are used for parts of the process. A small copper plating tank,
> tin-lead tank, and peroxide-sulfuric etchant along with fusing oil and
flux
> can be set up at home for probably a couple hundred dollars. To set up a
> fairly complete shop including drilling and imaging would probably cost
> between 2K and 3K. This would provide the capabilities of producing
> reasonably high quality boards. Oh, did I forget to mention getting the
> experience to know how to do it :)?
I've never done the full process Marvin describes at home, but there's a
commercial website that has quite a lot of useful information. Eniough to
encourag me to try it "one day":
http://www.thinktink.com/
(If you're like me, and keep that Java(script) stuff turned off, turn it on
for this site, as the menus need it).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
I have a TRS-80 Model 1. The monitor is third-party, the disk drives are third-party. I have all the documentation, plus NEWDOS 80.
Not wanting to trash it (chuckle), do you have a home or where's the best place to post this?
The machine is in NW Montana. I can't pay for shipping, although I will pack it carefully for shipping. In other words, the machine is free, FOB Polson, MT.
Any ideas?
Bob Bushnell
blrab(a)digisys.net
> Of course you could, but why would you want to? What's the problem with
> PCBs (or am I going to find out for myself when I get seriously into
> making them at home?)
Nothing except that I thought they were a more recent innovation. I was
thinking along the lines of, this is how you might build it with technology
available in 19XX
Can anyone give a timeline with (a) the invention and (b) the first commercial
availability of: PCBs, Transistors, ICs (perhaps divide up by technology and
scale of integration), and possibly other items of technology relevant to this
period (say, 1940 to 1970)?
Along similar lines, what multipin plugs were available at what date? In the
1930s and 40s, multipin plug and socket often meant something that plugged into
a valve (tube) base...
Philip.
This E-mail message is private and confidential and should only be read
by those to whom it is addressed.
If you are not the intended recipient, you are hereby notified that any
dissemination, distribution, copying, reproduction, modification or
publication of this communication is strictly prohibited. Please delete
the message from your computer and destroy any copies.
This message is not intended to be relied upon by any person without
subsequent written confirmation of its contents. This company therefore
disclaims all responsibility and accepts no liability of any kind which
may arise from any person acting, or refraining from acting, upon the
contents of the message without having had subsequent written
confirmation.
If you have received this communication in error, or if any problems
occur in transmission please notify us immediately by telephone on
+44 (0)2476 425474
> In article <7v20se$i4n$1(a)info.cs.uofs.edu>,
> Bill Gunshannon <bill(a)cs.uofs.edu> wrote:
> > Can anyone give me a rundown on the commands needed to use ZRQBC1
> > to format an RD52??
>
> > Is there docmentation available anywhere for XXDP?? People always
> > tell me UNIX is too cryptic, what would they say if the saw XXDP??
>
> I wonder what extent DEC's naming conventions led to their ultimate
> downfall? Once you're used to it you can tell a LA120 from an RZ28 and
> a KZPCM-AA from a FRPG4-WI, but damn...
>
> --
> In hoc signo hack, Peter da Silva <peter(a)baileynm.com>
> `-_-' Ar rug t? barr?g ar do mhact?re inniu?
> 'U` <pfy> Sigs with pfy's markov chain.
> -- "pfy", a markov chain IRC bot.
Is my memory of the breakdown of the diags correct?
+--> Diag software
| +--> Second diag
| |
ZRQBC1
| |
| +-->Revision C patch level 1
+--RQDX? disk controller (does the R stand for Rotating Memory Here?)
Always found DEC's PDP11/Vax naming conventions made more sense than IBM's or
HP's. (Except for the DL/RL/DM/RM/RK issues with boot rom input
vs. drive names...)
And their diag supervisor xxdp diags were much easier to deal with
than almost anything else. (I loved the early xxdp stuff you had to
deposit to constant locations to change the seek/read-write timings).
Bill
---
bpechter@shell.monmouth.com|pechter@pechter.dyndns.org
Three things never anger: First, the one who runs your DEC,
The one who does Field Service and the one who signs your check.
Hi!
Does anyone have an IBM 5155 (I think I got the model right) Portable PC
that they would want to sell/trade something for?
I'm trying to narrow my collection down to portables, since I sorta have
limited space, and I may be getting rid of (probably on the list) some of my
desktops.
-Jason
(general-one(a)home.com)
<My main belief is that nobody is going to keep a VAX anything running with
<dozens of simultaneous users. So, if a VAX is to be something close
Very errorloaded belief. It's done, being done. In 1993 the style of
computing is actually quite different than current. large companies used
VAX or as400 as central computers and maybe also servers to those PC
users that wanted application autonomy.
<Now, perhaps if we were to port Apache to the VAX, and used that I/O bandwi
<on multiple DS3s, well, that's great.
Exists, I know of a company using a bunch of 6000s to service a user base
of some 1000 systems never mind running all the batch jobs like payroll,
job costing, database updates and other mundane stuff.
<Hey, I'm not saying the original IBM PC was going to outperform the VAX 650
<but a modern PC will crush any VAX in any application, IMHO, with equivalen
<h/w attached.
NO, simple reason, PCs don't have equivelent hardware.
<1) The names of these busses?
Some are FDDI, Massbus, CI, HSI, SCSI(I/II/IIW...), and a few properitory
busses.
<2) Their uses?
Two general catagories, memory interconnect and Storage interconnect.
There are several IO interconnects as well.
<3) Their peak and average throughputs?
I think FDDI is still in the 100++m/bytes/Sec region. Though there were a
few parallel busses that were 50-100mbytes/sec rate.
I will not argue this as PC are finally going fibre and Gigabit eithernet
but thats 10 years after the fact.
<I certainly know for a fact that UNIBUS performed very poorly. I don't hav
<data at my fingertips, but it seems to me it was around 10 Mb/s (that
<megabits/sec) peak throughput. [I prefer measuring throughputs in bits/se
<since that normalizes across different bus widths.]
Also loaded with errors. Systems process things in chunks. FYI the
pdp-11/70 was a 1mips (I think it was also 1mfps) machine despite that
slow unibus.
<Fast dual-port SRAM solves the problem, but commodity PCs aren't designed
<that way. Also, the AGP bus uses mega-RAM to speed up PC graphics, for exam
Exactly they arent designed that way. The cpus might do better in a real
system but even then there are throughput issues. Your original arguement
WAS a 486dx would kill the VAX 6000-530. the answer is still not ever!
In the end it still takes 10k$ to do what 10k$ of vax did then.
The rather specious arguement of my daddy can beat your son is is pointless.
I can easily beat a PDP-8 with a slow PDP-11, what have I proved other than
the next generation machine is better (wasnt that the point of its design?).
In 1993, PCs were plentyful but they were not the applications killers.
What they were then was the cheap workstations with 640x480x8 or maybe
800x600x8 graphics and often a lot less. Could a 486dx be made such that
it would be a crusher box... yes but, there would have been no software for
it as PC compatability was a must have back then other wise it was just
another soso cpu.
Allison
<Of course you can. The exact details are a right fiddle (partly because a
<nixie tube is not a diode, so you are going to get sneak paths!), but
<basically you sequence the anodes of the tubes to the B+ rail and then
<ground the appropriate cathode for each tube.
Nixi is a threshold device so there are no sneak paths but the actuation
voltages are pretty fussy due to the hystersis.
<A _lot_ of calcultors had a multiplexed nixie tube display. It was much
<less common in test gear which is why I guess you've not seen it.
Really, never saw many that did, the vacuum florescent (bluegreen)
were generally mux'ed..
<You want to look at the 7441, and 74141. I seem to recall there being a
<TTL chip with counter, latch(?) and nixie driver all in one package. I
<can't remember the number but it was a 7414-something (74142/74143???)
74142 is the nixi (Counter, latch, decoder) and the 143 is the led/lamp
seven segement.
74141 is an pmproved 7441 and likely easier to find.
<And no, they don't seem to be in the more recent TTL databooks I have
<here :-(. I think there are still plenty about (if only in the junkboxes
<of people on this list :-))
My Ti data books have them (ca1976) as do the reference TI set from the
mid 80s. I'd expect they can be found easily enough.
Allison
<Has anyone else run into trouble reading 8 sector disks under Win95? I trie
<to read the IBM DOS 1.10 disk and just ran into the Abort, Retry, Ignore
<error message. When I booted it up and copied it to another disk on the
<Compaq luggable, everything worked out just fine.
W9x driver assumes default formats. use a dos box to copy the contents of
the disk to a format the winbox knows. FYI: Don't bother win9x in dos mode
as it's still the same drivers.
Allison
--- Sean 'Captain Napalm' Conner <spc(a)armigeron.com> wrote:
> One of the stories about the machine relate to a package that just showed
> up one day. They open it up to find a replacement fan for the machine. It
> seems that the machine in question had determined that one of the fan units
> was marginal and had placed an order for a new one from the manufacturer.
Tandem's do that. They used to print warning messages on the console that
failover had occurred, but people got out of the habit of reading the logs.
The solution: bypass the customer and order parts directly from the vendor
when faults were detected. Most customers learned that something failed when
a) a part showed up or b) a field-service engineer showed up.
-ethan
=====
Infinet has been sold. The domain is going away in February.
Please send all replies to
erd(a)iname.com
__________________________________________________
Do You Yahoo!?
Bid and sell for free at http://auctions.yahoo.com
At 04:01 PM 10/24/99 -0700, Mike wrote:
>(Hi Chuck!)
>
>Here's my back-of-the-envelope:
[snip]
Ok, you've considered the memory bandwidth without considering:
1) That disk transfers also happen across this bus.
2) Other I/O (mouse? Sound? Video?)
3) The interrupt load on the CPU.
As an empirical note the 16450 UART often could not be serviced fast enough
by the 486DX66 to prevent it from dropping incoming characters above 9600
baud. That was even with the "FastCOM" driver that came with Procomm plus
for DOS, not until the 16550 added a 16 (or was it 32) character FIFO did
it work. Now multiply that by 12? Say 9600 baud, every types a key. That is
12 interrupts to service while you're potentially trying to push out 12
streams of bytes.
Anyway, the VAX (and most DEC gear) got around this by having channel
processors _everywhere_ and of course the modern PC has channel processors
_nowhere_. (IDE taking this to the logical extreme)
Somewhere I've got an 8 port serial card that was built for the 16 bit ISA
bus (it has 8 mini-din connectors on the card edge). The thought was to run
UNIX on a 486 and use terminals for multiple students. It didn't work. The
PC couldn't keep up. I fully admit though that given source code I might
have been able to make it work :-)
--Chuck
<> If you're doing ray tracing, get a fast PC.
<> If you're timesharing dozens of people, a VAX is not a bad choice.
<
<I remain unconvinced(!).
Then what would work better for fast ray tracing. and why does my ISP have
a 24x250mhz SGI and not 24 PIII/xeons?
<> It's all about "balance" and truly good designers can get good balance fo
<> the task at hand without being stuck in some rut.
Big time Chuck. I like the mix, I like to mix.
Thinking of the 11/55 story. 1970, KA10 (PDP10) 300 users (mostly TTYs)
in schools never using more than maybe 70%. Plus batch processes for version
clerical tasks related to the operation of the BOCES LIRYCS timeshare
system. Now That was BIG iron (12 6ft racks!). But if I took all the PCs
needed to provide the same interconnected services and stacked them up
they would easily outweigh the KA10 and much more power, try 300x200W
that is 60KW, the Ka10 was under 10KW and like near 6KW.
<> (For Mike, have you ever actually run a 486 based PC architecture machine
<> with a dozen actual serial interfaces connected to terminals? It is
<> instructive because the damn things saturate the ISA bus and no disk
<> traffic happens at all!
<
<(Hi Chuck!)
<
<Here's my back-of-the-envelope:
<
<The 16-bit ISA bus on a 486dx2/66 runs at 8 MHz. The total bus throughput
<for memory operations is 32 megabits/sec. (4 cycles = 500 ns, 16 bits/cycle
yes, but the IO is polled or interrupt and that adds 500% overhead.
<If your dozen uarts are on a memory-mapped card, and you're pumping 19.200
<b/s continuously to the dozen uarts, that's 184,320 b/s required by the
<uarts. That's only about 0.6% of the available bus bandwidth (about one
<uart transfer every 174 Main Memory references.) Yes, you do have to work
<with such slow memory, and now we understand why cache memory was so import
<even on dx2/66 motherboards. So, yeah, keeping a dozen terminals blazing
<output would be "fun" with an ISA-only bus!
It's not 184320, thats how many are transfered, not the process loading.
The system might require that to be dispersed across 12 buffers and there
are overheads associeted with that. So your understating the actual task
and loading. While the ISA bus is running at its speed the cpu is basically
locked to that and the memory accesses that could occur, don't.
The actual performance is not impressive. FYI: vax using the same approach
would really be poor too. This kind of IO was typical of PDP-11s
and they did it very well. The big iron solution is hardware and non
competeing busses to unload the cpu from the IO task and not burden the
memory with the slow IO cycles. Therein is part of the difference.
Old iron treated the cpu as a valuable resource and were designed with the
idea that cpu cycles were expensive.
<(Incidentally, I am -not- advocating ISA as some sort of "wunderbus"; on th
Yes it's perfomance is par with mid range(ca 1977) unibus and Qbus of 10
years before. By 1981 DEC had decided that those busses were ok for their
use but they needed faster buses. FYI BI bus was a 64bit bus (minimum
access was a 8byte chunk) and in use about 8 years before PCI was conceived
(or VESA, VL). the big iorn was always trying to feed the data rate habit
and usually long before PCs.
< contrary, I remain amazed that it has taken the PC industry as long as it
< has to recognize the importance of I/O speed. 64-bit 66 MHz PCI and 2x AG
< are steps in the right direction... Yes, the microcomputer industry seem
< hellbent on re-discovering what the mainframe and mini guys knew 20 or 40
< years ago...)
Yes. thats the whole point.
Allison
>I've got a fair number of ST41201J SMD drives (1.2G) in System Industries
>carriers in Milpitas (near San Jose); if anyone needs them we can work out
>a trade.
>
>I've recently learned that there are different flavors of SMD. The
>high-transfer rate drives use the SMD-E interface, which uses differential
>ECL transceivers for the data and clock on the radial interface, vs.
>TTL-compatible stuff on the earlier drives.
I thought all SMD interface drives used differential ECL signals on the
radial cables...
>I'm hoping to use some of these on a system that was originally set up for
>Fujitsu Eagles (M2351), but I haven't found any online reference that
>indicates the data transfer rate or geometry of the Eagle, or whether
>it uses SMD-E.
A very good source of SMD drive geometry information is the "Sun
format.dat" file that's been floating around the net for the past
15 years or so.
The Eagle is 842 Cylinders, 20 Heads, and (assuming 512 bytes/sector)
49 or 50 sectors per track. The data rate is 15 MHz. Is this
what you needed to know? I have manuals for most of the Fuji drives.
Incidentally, the Fuji Eagle manual is titled "M2351A/AF Mini-Disk
Drive Customer Engineering Manual". Most weenies today wouldn't call
a drive that weighed over 100 pounds "Mini", but they don't know what
they're talking about!
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
>> Of course you could, but why would you want to? What's the problem with
>> PCBs (or am I going to find out for myself when I get seriously into
>> making them at home?)
>Nothing except that I thought they were a more recent innovation.
Than... ?
> I was
>thinking along the lines of, this is how you might build it with technology
>available in 19XX
Printed circuit boards were used in consumer electronics as early as
the late 1940's. These were true "printed circuits" (i.e. copper traces
applied to substrate) and not the wamsy-pamsy etched circuits you'll
find today :-).
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
I am setting up a class for 6-7 graders and need a few punch/hollerith,
etc. cards to demonstrate past equipment/practices.
Can anyone help?
Thanks
Ben Sands
Bsands8417(a)aol.com
This appears to be the procedure, though I forgot to mention that the copper
has to be applied electrically to the drilled boards prior to application of
the second (after the .000030" flash of copper which is chemically applied,
but the dry-film I meant was indeed the solder mask. All my boards were
made with dry-film solder mask, since that worked so well for my wirewrap
boards. I liked the appearance, and silkscreened legends went on top of it
wit little smearing and blurring, so they could be REALLY small.
I never considered letting a shop do parts of the job, but I'll explore that
before I give up completely.
thanks for the explanation.
Dick
-----Original Message-----
From: Marvin <marvin(a)rain.org>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, October 24, 1999 10:48 PM
Subject: Reliable PCBs at home
>
>
>Richard Erlacher wrote:
>>
>> First of all, I haven't read ALL of this thread, but I recall Tony or
>> someone else replying to him saying something about the method for making
>> plated through two-sided boards in your home. I've never met anyone
aside
>> from professionals with scads of equipment who could do that, but it
seems
>> to me that the method which was described to me was to start with bare
>> fiberglass/epoxy panels, drill them, then apply a slightly conductive
>> coating in liquid form which had to be forcibly dried (perhaps baked)
before
>> the resist was applied. The boards were then exposed, the films applied
to
>> registration targets on each side, to a powerful UV light, for which some
>> prefer to use direct sunlight, and the boards subsequently developed,
then
>> etched.
>>
>> Has any of you ever encountered an approach to this that could be managed
in
>> the home environment with equipment costing, nominally, less that a
k-buck
>> or two and achieving nominally 10-mil traces with 8-10 mil separation or
>> anything close to that? How about a dry-film solder mask?
>
>First of all, there are service shops that will take a drilled board, do
the
>PTH process, and electroplate the desired amount of copper onto the board.
>The normal process for making PTH boards is as follows.
>
>The copper clad laminate is cut to panel size and drilled. The drilling is
>usually done on an NC machine. The NC program can either be supplied as a
>drill file, or it can be hand programmed. Hand programming involves taping
>the artwork (or more likely a copy) to a programing table, marking the rout
>to follow for each drill size, and then just the grunt work of centering
>each hole in a scope, and pushing a foot pedal that records that location.
>
>There are a number of different processes for doing PTH, but the most
common
>is to take the drilled panel(s), run it through an electroless copper line
>(cleaning, catalist, accellerator, electroless copper) that will put about
>30 millionths of copper on the board, and electroplate about .3 mill or so
>of copper on the bare panel (enough so the rest of the process doesn't
>create problems with the plated through holes.)
>
>The next step is imaging and how that is done depends on the required
>quantity and line density. What I used (prototype/short run shop) was use
>dry film. The board is cleaned and laminated with a photosensitive film.
The
>artwork was transferred to diazo film, and the diazo films were used to
>actually image the board. At this point, the board is developed and the
>copper you see is what you want.
>
>The rest of the process is fairly short. Electroplate copper up to the
>desired thickness, electroplate tin-lead, strip the dry film, etch, gold
>plate the fingers if necessary, fuse the tin-lead into solder, route,
clean,
>and ship. The etching is usually done by machine using an alkaline etching
>solution.
>
>Doing the process at home can be done with a minimum of equipment if
service
>shops are used for parts of the process. A small copper plating tank,
>tin-lead tank, and peroxide-sulfuric etchant along with fusing oil and flux
>can be set up at home for probably a couple hundred dollars. To set up a
>fairly complete shop including drilling and imaging would probably cost
>between 2K and 3K. This would provide the capabilities of producing
>reasonably high quality boards. Oh, did I forget to mention getting the
>experience to know how to do it :)?
>
>BTW, I think you just meant dry film above. Dry Film Solder mask does
>require UV curing and is probably impractical for home use. However silk
>screening the soldermask and legend is easy and inexpensive to do at home.
<It states: "The VAX 6500 processor delivered approximately 13 times the
<power of a VAX-11/780 system, per processor."
Your confusing the price of bricks with the weight of concrete.
The MIPS metric is not accurate, I don't know if there is one. Further
VAX doesn't spend all its cycles doing drystones. In the real world
you do some math then do a LOT of housekeeping.
<To me, that means "13 MIPS". 13 MIPS is about 2 to almost 3 times slower
<than a 486dx2/66.
Until you fill memory. then the contest reverses. The 486s of the time
were doing good at maybe 5meg bytes/sec and thats SLOW. The real test
then and now is what the system does with relational database of say
100mb is size.
< CPU MIPS MIPS
< System OS CPU (MHz) V1.1 V2.1
< ---------------------- ------------ ----------- ----- ------ ------
< VAX 8650 4.3 BSD ----------- 18 6.3 6.2
< cc -non_shared -DUNIX -O5 -ifo
It's a non compare as an 8650 is not a 6000 anything. there are differnet
memory bandwidths and IO bandwiths in effect and the slowest is much faster
in action than an 8650.
<And, back of the envelope, the 6500 was 2x the 8650.
And it was 1/5 the volume.
<I don't know what it is about collectors that somehow confuses their
<memories of the past; maybe their internal core memories have suffered som
<bit flips? ;-) (I have some old junk, too, so I consider myself in the
<same camp...)
Well, first of I'm not your average retrorevionist PC collector. I worked
for DEC for 10 years (83-93) spanning the era in quesiton.
<Fact is, these old machines were slow, noisy, hot, power-guzzling behemouth
<compared with what we have today.
Yes. Compared to the "hot" 486dx/50 in 1992 we were using the little
(they are 10wx4Hx16D) VS3100s (same size and lower power than your power
guzzling PC) as the PC crusher and those were typically 2.4-3.5VUP range.
Oh, and I've used a VS3100 recently as a server at work for test purposes
and the 3100/m10E clobbered the P166mmx/scsi box running NT.
<As you know, the vax would run the X -client- which, of course, is not
<much of a load. And as for running 50 users, heck, at the VCF 3.0 there
<was a guy showing an 8080 running timesharing on a bunch of terminals!
Yes, I know and have done. I've tried to run a p133 as a unix host (not
a web server) as a timeshare client and it doesn't load as well as the
VS2000 I have. The 8080 timeshare FYI had terrible latency!
<Therefore, to me, you have to measure the performance in some repeatable
<way. Dhrystone is not the perfect benchmark (which is close to an oxymoro
<anyway), but it is -a- benchmark for integer CPU performance.
Yes so... When I'm running a relational database that number means absolutly
nothing. Running a word processor it's means nothing.
<It's too bad that you had to run w3.11; I'm assuming you're running a real
<OS on the dx2/66.
In 1993 what real OS would have a PC running? DOS? Concurrent dos, SCO
unix? Venix? The hot IO interface was 10b2 and AHA5142 SCSI. The really
hot box was the 4cpu (486dx/50) box NCR made, there was no real OS yet and
w95 was still beta testing on that box.
<Now, let's talk about busses. Just how fast -was- this CI? Let's compare
<that with 66 MHz 64-bit PCI, which has 66e6 x 64 = 4,224,000,000 bits/sec
<peak throughput. What was CI's throughput?
CI, cluster innerconnect was was fast when PCs were running ISA-16. If
memory serves it was a 24-32mbytes/s rate. PCI-66 is now, and slow Alphas
use it. The difference is you could have multiple CI busses and sorry but,
only one PCI. Also PCI is not that fast. It's bursty and can run peak
rates that fast but what is the CPU doing when PCI is honking at that rate?
Answer? WAITING, if your real lucky running from the cache!
But then when VAX was running CI what was the PC running? OK ISA-1 at
some 8meg bytes/sec and memory interfaces were typically 70ns 32bit wide
non-interleaved with caches. SCSI was maybe 10mb/s. the less than
popular MCA bussed IBM hardware were much fast than the ISA and VL bussed
counterparts.
Running VMS in the early 90s we had SMP that was scaleable using LAVC
(cluster over eithernet) and CI. There were also the BI and other
interconnects.
The point being your trying to save your arguement with _now_ hardware
against _then_ hardware. PCs with then hardware were the industry joke
for uptime, reliablility and performance, the AS400s, VAX, Prime, and
others were the systems choice for getting work done on the larger scale.
PCs in many ways are still behind the "big iron" of the early 90s, as
they still lack a really good OS (linux, freebsd are contenders though).
The hardware is not mature, they keep creating new standards that barely
get debugged before they are pass`e. It's always amazing to see older
systems bumping along getting real work done, usually while the PC user
is rebooting for the third time today.
Allison
In a message dated 10/25/99 4:05:18 AM Eastern Daylight Time,
mikeford(a)socal.rr.com writes:
> >Hi!
> >
> >Does anyone have an IBM 5155 (I think I got the model right) Portable PC
> >that they would want to sell/trade something for?
>
> You mean a 5140?
>
well, its all semantics ,but the 5155 is called the portable pc and is a big
suitcase sized machine. the 5140 is the covertible dual floppy laptop.
d
DB Young Team OS/2
--> this message printed on recycled disk space
view the computers of yesteryear at
http://members.aol.com/suprdave/classiccmp/museum.htm
(now accepting donations!)
<That's fascinating. Take obsolete hardware and architecture (vax), and
Define that, obsolete is when it doesnt do the job.
<>The problems is equivalent hardware. You can't configure a PC
<>like a VAX, they are two different types of machines. A PC
<>is tuned for a single user, while a VAX is tuned for many users.
<
<Amen! Thank you!
You obviously didn't understand, likely don't care to. One observation is
those that claim a narrow pardigm often end up eating it. VAX is not beall
but then again it represents 20 years, in excess of 8 busses (cpu to memory
and primary IO) and one major OS that still is secure and fast. PCs are
an evolving species and wer are not up to the maturity level for even the
OS not minding the hardware.
<Remember, I was just making the observation that the integer performance of
<the vax 8650 is worse than a dx2-66. I think single-user; I run single-use
<machines. The future is single-user with vast network-accessed databases.
All served by big iron with 64 bit cpus, why is merced so hot to beat
Alpha.
<Again, with -equivalent hardware- it certainly would.
Ok. find a PC that you can cluster. Set it up in minimal time using an
out of box OS.
<having given up on Big Iron. Also, the market sizes for IBM, HP, and Sun'
<"big iron" exist specifically to be those back-room servers that can do lot
<of disk I/Os per second (the web, eh?).
Even the web needs lots of IO, and more every day.
<BUT, I would like the Vax Lover Crowd to acknowledge that they integer
<performance of their machine is pathetic.
If that all you hang you hat on you win. Your still missing the point
and most everything with it.
<> Its not the speed
<>of the individual bus, but its the number of busses.
<
<That's of course bull.....
<
<>The more busses, the more parallelism and the less waiting.
<
<-IF- the speed of the busses is high enough!
They have to be very very fast and the system on the bus very very fast
and then you still have bus bandwidth conflicts. Therein lies the truth,
if someone delivers a PC that has multiple independent PCI buses that can
run in parallel will you start claiming that is better?
<>One
<>fast bus works well until you want to do multiple things, and
<>then it quickly becomes a bottleneck.
<
<Excuse me? Could you please back up this assertion with data? After all,
<at -some- point, all these busses have to get their data into/out of the CP
<right? And -that- is a "bottleneck" for sure... (Sure, you can have
<channel-to-channel I/O, but most aps are not just shuffling bits.)
How about channel to Memory where the cpu get and put most of it's stuff.
Or one bus that serives slow IO and another that is for memory acesses
for multiple cpus at full bandwidth.Anyone thats stuied computer design
and not software engineering would have studied system design and bus
throughput models.
<Sure, but AGP is better than -no- AGP, and it does show that there are othe
<busses available on a PC, yes? (Which was my original point.)
NO! those busses cannot operate in parellel and they operate and the
expense of each other. I'd add if you plug in a slow card the plug and
pray hardware may configure to that slower card at the expense of faster
ones around it.
All said and in the end, we have a troll.
Allison
At 07:56 PM 10/24/99 -0700, you wrote:
>Excuse me? Could you please back up this assertion with data? After all,
>at -some- point, all these busses have to get their data into/out of the CPU,
>right? And -that- is a "bottleneck" for sure... (Sure, you can have
>channel-to-channel I/O, but most aps are not just shuffling bits.)
Well ... I have some experience with high-speed switches and crossbars
in parallel supercomputers (as a user). The fallacy in your thinking is
that you believe that moving data around is not "processing". You still
think that the real processing takes place only at the cpu. Matter of fact
is that, in the real world, as data goes through each driver/buffer and
process in the OS on its way to the process that will actually do something
with it (i.e., actual "integer-op-related" cpu time) there are usually several
large block transfers. If all of this can happen without hogging the cpu
(and you need hardware to do it) you can bet that the corresponding machine
will be many times faster than a machine with a PCI bus.
I once read that the average number of moves for net data (after it is in
memory) for data from input through tcp/ip stack through OS through
application is on the order of 4.x ... I think in some Sun literature...
First of all, I haven't read ALL of this thread, but I recall Tony or
someone else replying to him saying something about the method for making
plated through two-sided boards in your home. I've never met anyone aside
>from professionals with scads of equipment who could do that, but it seems
to me that the method which was described to me was to start with bare
fiberglass/epoxy panels, drill them, then apply a slightly conductive
coating in liquid form which had to be forcibly dried (perhaps baked) before
the resist was applied. The boards were then exposed, the films applied to
registration targets on each side, to a powerful UV light, for which some
prefer to use direct sunlight, and the boards subsequently developed, then
etched.
Has any of you ever encountered an approach to this that could be managed in
the home environment with equipment costing, nominally, less that a k-buck
or two and achieving nominally 10-mil traces with 8-10 mil separation or
anything close to that? How about a dry-film solder mask?
Please share your experience, real or semantic.
Dick
-----Original Message-----
From: Roger Merchberger <zmerch(a)30below.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, October 24, 1999 5:21 PM
Subject: Re: OT: how big would it be? - PCBs at home
>On or about 07:15 PM 10/23/99 +0100, Tony Duell was caught in a dark alley
>speaking these words:
>
>>Oh, don't get me started on trying that... And that toner-transfer film
>>isn't that good either...
>
>Isn't that good? My, you're certainly in the mood of understatement today,
>Tony. I've tried that stuff (thinking... This is cool. I can finally
>prototype PCB boards for my classic interfacing projects relatively
>easily...) and I can officially say that it really, really, really sucks.
>And the worst part? It's not that cheap, either.
>
>(certainly affordable, if it worked... which it doesn't.)
>
>For the problems with acetate, try getting a transparency film designed for
>the actual printer that you intend on using. Toners are quite different,
>including their fusing temperatures, fineness, and other factors. Another
>thing to watch for with this iron-on crap (or laser film, or whatever):
>Don't run it thru the printer twice. The high fusing heat changes something
>in the media that seems to make it right close to worthless the 2nd time
>round.
>
>I think that's what happened to me; the 600 DPI HP's use a "micro-toner"
>which fuses at a higher temperature, and I think it changed the media so it
>wouldn't "iron-on" easily, not to mention I don't think the iron got hot
>enough to xfer the toner if that's a factor on the process working right.
>
>Some of the newer "photo" inkjets might work pretty well for artwork,
>too... My wife's Epson Photo 700 does this thing called "micro-weave" for
>the photo papers. It essentially takes 1/4 swipes at the image, and prints
>the image 4 times at 1/4 density with the full printhead, so there's
>virtually no banding. I've not tried it (have a laser) but it just might
work.
>
>As always, YMMV and all that...
>Roger "Merch" Merchberger
>=====
>Roger "Merch" Merchberger -- zmerch(a)30below.com
>SysAdmin - Iceberg Computers
>===== Merch's Wild Wisdom of the Moment: =====
>Sometimes you know, you just don't know sometimes, you know?
Another step in my ongoing attempts to bring some focus (and room) to my
collection.
(and help finance a possible upcoming major restoration project)
Ohio Scientific Challenger 1P microcomputer
Includes 5.25 diskette drive, manuals, software (original disks plus extras).
Unit is in overall good shape, some paint wear around the keyboard (no
wrist rests back in those days). Pictures available on my web site. Have
not fired it up in some time so it exact condition is unknown but it is
complete.
I'm thinking $250.00 (plus shipping) unless someone convinces me that I'm
totally out of the park on that. Interesting trades (see the 'Most Wanted'
list on my web site for ideas) always entertained.
-jim
---
jimw(a)computergarage.org
The Computer Garage - http://www.computergarage.org
Computer Garage Fax - (503) 646-0174
<> VAX 7000's in a brand new computer room. Said corporation has numerous
<> computer rooms with VAXen, and these systems are heavily used.
<
<Maybe I should have said "Nobody -sane- is going to....".
Try managing that, nice all in one place system. Sanity is restored.
<How fast is a Vax 7000? http://www.digital.com/timeline/1992-3.htm
<describes a little about the VAX 7000, but no hard speed data.
Far to brief for you spec's experts to appreciate.
<Incidentally, the vax 7000 was introduced 7 years ago; have there been any
<upgrades since then?
Yes, disks and network peripherals. Lower cost. and it's scaleable for
multiple cpus and clustering.
<The paradigm today is client on Ethernet, server cluster in the back room.
<Scalable, cheap, reliable.
Scalable, buy a bigger server? Run out of net bandwith? Multiple servers
that are NT based add one more? Been there doing that. HAve they figured
out how to cluster PCs (I know Linux Beuwolf... and right out of a box too).
Gee and I thought adding another VAX to a cluster was a powerful scaleable
solution. That failover capability from the 80s is pass`e too I'd bet.
<One Big Box In The Back Room is what people did in the 40s, 50s and 60s....
And 70s, 80s and even the 90s. The big box in the back room is called a
server now (likely several servers).
<You're right, speed isn't everything; it's the -only- thing! ;-)
Yes, rebooting faster is better when you have to. ;)
<My PCs are damn reliable; are you buying junk? They are -waaaaaaaaaaay- mo
<reliable than the VAX-11/780s, VAX-11/750s and VAX-11/785s that I have
I'd hopes so, those are 20 years old. Will your PCs even run after 20
years? 10 years? How about 5? Then again why not run that super fast
VAX beater 486dx2/66 still?
<used in the past. (I run BSDI unix on a Pentium Pro, as well as NetBSD on
<other machines, and they have -never- crashed.)
Good for you. Run NT for a while and get to appreciate the rest of the
real industry. Do you serve 6 different databases? How about thin windows
clients from them? FTP and web pages are nice can they serve out disk
space for W95 workgroups and legacy dos programs? Whats the backups like?
Do the 40 clientshave a back up schedule to the server(s)? What fun it is
when the user changes their setting and locks up their workgroup? How
system security management for PCs, servers?
Well, thats a sample of the Intranet I run and maintain. Can't say I like
all the MS stuff but I'd realy hate to train users for unix/linux that
barely want to deal with PCs at all. For a small business a common system
based on big iron is really cheaper and easier to maintain.
Allison
I moved my PDP-8/e this weekend and have been inventorying and testing
various components. At the moment, the PSU isn't cooperating. ISTR
there were some molex connector jumpers at various points, but I may be
missing one or two.
Up on the front, I have an empty 3-pin molex shell on, IIRC, P5. On the back,
there is one 3-pin jumper in place and an empty 3-pin connector next to it.
I get no lights, no sound, no nothing out of this. The fuses are good.
Any suggestions?
-ethan
=====
Infinet has been sold. The domain is going away in February.
Please send all replies to
erd(a)iname.com
__________________________________________________
Do You Yahoo!?
Bid and sell for free at http://auctions.yahoo.com
<Has any of you ever encountered an approach to this that could be managed i
<the home environment with equipment costing, nominally, less that a k-buck
Being close to doing this I can speak about it some.
The key to doing plated through hole is a process called electroless copper
plating. I don't do that for one reason, it's a nasty process and the
materials are poison and its wastes are poison to the max. I farm it
out.
the films for high res stuff are gerber photoplots you can farm that work
out. laser printer plots are not adaquate for anything less than 25mil
features and even then... At work we pay 87$ to get B size plots from
Acad-13. This is not cheap and is likely the upper end as I get them
elsewhere for ~20 for A size.
the drilling, it's possible to build a threeaxis drill press that is NC
controlled with better than 0.005 accuracy with relative ease. that will
drill for you. With patience and a simple jig in a drillpress you can do
this by hand.
Sensitizing, exposure and development are trivial. the photoresist can be
very expensive though. They run from 300 to 800 USD a gallon (that a lot)
and getting a pint quanity can be hard. The easy way is to pour on the
resist (under safelight) and spin the board at 3000rpm for 20 sec. The
coat is very uniform then and quite thin. Exposure is a light box with
two UV lamps of adaquate size(20w, 2ft, shortwave). Development is generally
whatever the resist requries and takes a few minutes. htere are positive
resists and also negative, pick the right one to match your photoplots
(or pick the photoplots to match the resist)!
Etching the board is simple and can be handled by most hobbiests.
<or two and achieving nominally 10-mil traces with 8-10 mil separation or
<anything close to that? How about a dry-film solder mask?
Dry film mask may be part of the resist used or a seperate operation. It's
not essential but it helps. A z280 board under devlopment using 10 mil
features, two sided with PTH is what I'm basing my experince on. Also
the company I work for does foil heaters and temperature sensors so the
have a minimal PCB operation (no drilling, single sided, no PTH).
Allison
On Oct 22, 15:20, daniel wrote:
> Making PCBs at home is a rediculous waste of time. I have a vacuum
lightbox
> here as well as a commercial processing system, a silkscreening set up,
even
> a wave solder machine in my home and nothing compares to what the big
guys
> can do and charge for the same thing.
If you're trying to emulate the way a professional PCB house will make
them, or if you need moderate to large quantities, I suppose I agree. But
for two or three boards, I strongly disagree. I've made dozens, possibly
hundreds of PCBs at home or at work, and it doesn't take that long, nor is
it very difficult. I certainly prefer it to wire-wrap. Of course, you
typically won't be able to get such fine lines, and putting two tracks
between the pins of a 0.1" pitch DIP isn't something I'd do. I wouldn't
consider using a professional PCB company for a one- or two-off unless it
truly was very special, or a prototype for something that later would be
made by the hundred.
I make same-size artwork on a decent laser printer, and expose that onto
sensitized boards. With a little care, registration is easily good enough
for double sided PCBs. It's even possible to do plated-through holes,
though I don't -- I use track pins, because the through hole stuff is
relatively expensive.
> My last *production* company use to
> make its own prototype doublesided PCBs in house and it wasn't worth it.
I
> have a company I use now that will make me a double sided PCB, GOLD
PLATED
> contacts, solder mask both sides (pre-drilled of course), and silk
screened,
> and cut for less than a $1 a board in quantities of 500.
OK, but do they also charge $490 for a one-off prototype? Most companies
here charge according to the number of layers and amount of setup -- and
that's mostly related to the number of plated holes, not board area.
> Pre-sensitised boards are useless as they usually come flawed and the
> coating thickness is not consitant. The company I use now for PCBs used
a
> "roll" of sentised film that was "ironed" onto a 3' X 3' board. Far
better
> process.
Maybe, but I've never had a problem with pre-sensitised board. Sensitising
it myself with an aerosol turned out to be a less-than-clever idea, though
:-)
> Don't forget a good GERBER and NC drill file is needed and most PCB
> manufacturers find little problems with the files that you may not
uncover
> in
Most PCB houses here are perfectly happy with 2x size artwork, and many
will accept same-size, possibly with a small surcharge.
Marvin mentioned a number of ways to produce artwork. I've seen most of
them used. Dot matrix printers aren't usually very good in terms of
black/white contrast, nor sharpness (but often OK for x2 camera-ready
artwork). I once discussed using an offset litho press to print directly
onto flexible PCBs, but I don't know if the person I spoke to actually did
that -- it should certainly have much higher resolution than a silkscreen.
And people really do use tape on mylar film (well, maybe not much
nowadays, but it used to be common). Lots of hobbyists over here print
onto acetate or drafting film with a laser printer, and that works pretty
well -- it goes straight into my light box.
Daniel wrote "He drills the boards first, then photosensitizes
them. They get UV, then he develops them in water (I think it was). Then he
electroforms copper to create plate through holes, then tins, then gold
plates, I think then he did the solder mask on both sides (I am sure that
was silk screened) and finally the boards were silk-screened (layout), then
cut." That's a fairly typical commercial method, except it wouldn't be
water development. At home, it would be a weak solution of caustic soda,
but that "goes off" very quickly, so a more esoteric substance is used
commercially.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Several people have gone after this topic many different times. It can't be
"won." It can't be won because computers are tools and one can always find
an application that makes less efficient use of the tool to "prove" their
point.
If you're doing ray tracing, get a fast PC.
If you're timesharing dozens of people, a VAX is not a bad choice.
Its all about "balance" and truly good designers can get good balance for
the task at hand without being stuck in some rut. My favorite example was
the HP2000 with BASIC supporting 40 users. In our lab at school we had one
of the "fast" ones (it had some addon from a floating point company (FPS?))
and it was considered too pokey for anything compared to the 11/55. But
over in the business school the very same model (sans FP, but same group of
machines donated by HP) was comfortably running what seemed like zillions
of HP terminals in HPBASIC. Balance.
--Chuck
(For Mike, have you ever actually run a 486 based PC architecture machine
with a dozen actual serial interfaces connected to terminals? It is
instructive because the damn things saturate the ISA bus and no disk
traffic happens at all! On a PCI equipped bus with the users coming over
the network via telnet its workable, but for terminal based I/O the DEC
timeshare systems were (and probably still are) the best that you can buy.)
A junk dealer I stay in touch with tells me he has an ancient computer he
insists is labelled "Anderson Digital Computer". He says it is a metal box
containing a screen and a separate keyboard.
I'm to go to see it this week some time. Can anyone shed some light on what
this might be?
He knows nothing about computers so it might be an XT clone for all I know.
Hans
<No confusion; there are simply different metrics for performance and she's
<using a different one than you. You are both, in fact, correct. The 486
<will outperform the VAX in integer performance, but the VAX has bundles
<more bandwidth to disk than the 486 ever dreamed of.
Rodger that but also to memory and IO as well.
It's pretty difficult to interface more than a handful of serial lines to a
PC. My MicrovaxII comfortably has 32lines (all running at 9600 as that was
the fasest modem in 1989!).
<> Fact is, these old machines were slow, noisy, hot, power-guzzling behemou
<> compared with what we have today.
<
<No argument there ;-)
No facts!. By 1990 vaxen and other vendors (sun, Appllo, IBM...) had
pizza boxes and made PCs look like they were running in reverse at no
higher power, often higher res video and better IO.
VAXen were amoung the first to run busses like FDDI and broadband as well
when PCs didn't have interfaces for that yet.
Allison
This is going to the CLASSICCMP and NetBSD port-VAX lists, and to the two
PDP-11 newsgroups.
RE-PC in Tukwila, WA (south of Seattle) has a whole palletful (at least
six) Seagate 'Sabre' series SMD drives NEW in their original packaging.
These are already in their carrier tray with a power supply. I don't know
capacity or model number -- was rushed, didn't have time to dig -- but I do
know that this is the last chance to get them before they're scrapped.
I did look at one, briefly. They appear to be the earlier series of Sabre,
the ones that sat vertically in their mounting tray, as opposed to the
later series that sat flat and were physically smaller.
I also confirmed that they're SMD interface by direct viewing of the
connectors: One 60-pin and one 26-pin Berg male header, standard .050 pitch.
Initial asking price is $20.00 per unit, with definite discounts possible
if you get more than one. To put it another way, the store would rather
sell them than scrap them, and the manager of the place does recognize that
there are those of us who do use the older hardware.
Contact Maurice from 10:00 - 19:00 PDT at 206-575-8737 (press 0 during the
voice announcement to bypass said announcement and start the phones
ringing). They're closed on Sunday, but they'll be open tomorrow (Saturday).
I hope this is of interest to at least some of you. Thanks for reading.
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner and head honcho, Blue Feather Technologies
http://www.bluefeathertech.com // E-mail: kyrrin(a)bluefeathertech.com
Amateur Radio: WD6EOS since Dec. '77
"Our science can only describe an object, event, or living thing in our
own human terms. It cannot, in any way, define any of them..."
Today's haul. Found at a garage sale! A complete HP-86A computer system.
Here's what I got.
5933-7832(D) Series 80 Personal Computer Retail Price List
HP/5933-7804 Series 80 Personal Computer Software Catalog (6/83)
00087-13519 Word/80, HP-86/87, Hewlett Packard Series 80 case w/ Manual,
pocket guide, 1 5.25 fd, ovl.
00087-13511 VisiCalc PLUS, HP-86/87, Hewlett Packard Series 80 case w/
Manual, pocket guide, 1 5.25 fd.
00087-13520 File/80, HP-86/87, Hewlett Packard Series 80 case w/ Manual,
pocket guide, 6 5.25 fd.
00085-13046 Surveying Pac, HP-83/85, Hewlett Packard Series 80 case w/
Manual, 1 5.25 fd.
82950-90001 HP 82950A Modem Owner’s Manual
00087-90121 I/O ROM Owner’s Manual
00085-90003 rD HP-85 Standard Pac Manual
00086-90014 Introduction to the HP 86
00087-90017 HP-86/87 Operating and BASIC Programming Manual
82901-90001 HP 82901 M/S, HP 82902 M/S Flexible Disc Drive Operator’s Manual
82937-90017 HP-IB Interface Owner’s Manual
00087-90614 Miksam ROM Owner’s Manual, HP-86/87
00087-90612 Miksam ROM Pocket Guide, HP-86/87
00087-90141 Assembler ROM Pocket Guide, HP-87
00087-90001 HP-86/87 Pocket Guide
HP 82950A Modem
HP 82909A 128K Memory Module
HP 82913A Video Monitor
HP 82937 HP-IB interface
HP-86 computer (“A” model with built-in parallel printer port and two
built-in floppy drive interfaces.)
83A Okidata printer.
HP ??? Parallel printer cable
HP 82929A Programmable ROM Module
HP 82936A ROM Drawer with:
000877-15002 Plotter ROM
00087-15003 I/O ROM
00087-60912 “Service ROM-- System”
00087-12035 System Demonstration Disc, HP-86/87 (5.2.5” disk)
00083-12056 82950A MODEM Communications, Series 80 (5.2.5” disk)
00087-15007 Assembler (5.2.5” disk)
Not bad for one day! :-)
Joe
On Oct 23, 19:15, Tony Duell wrote:
> We found that toner didn't stick that well to acetate film, and that we
> often ended up with gaps in tracks, etc. Amazingly, printing onto _paper_
> and giving it a very long exposure in the UV box helped a lot. Sounds
> crazy, but I've got the boards to prove it :-)
I find drafting film is best - but make sure you get the type that
withstands the heat of a laserprinter or photocopier :-)
> Many components can be soldered on both sides (Turned-pin IC sockets help
> here, but I use nothing else anyway). For those that can't I use the
> proper track pins. The PTH 'repair' kits are out of this world when it
> comes to prices...
I don't like soldering components on both sides, because it makes
modifications/repairs harder later. For special purposes, I do sometimes
use pins extracted from turned-pin sockets, though, and I don't mind
soldering those on both sides.
> There's always the good old HP plotter with a metal-tipped pen onto film.
> Takes a bit of fiddling, and it's slow, but it works. And it's a _lot_
> cheaper to find an old HP A3 (or larger) plotter than a similar
laserprinter.
I forgot about that one -- silly, because in a previous job, we used to do
that quite a lot.
> For small board (<A4), a laserprinter seems to be the way to go for the
> hobbyist. Pick up an old CX or SX engined machine and rebuild it (this
> _is_ classiccmp, after all) :-)...
Yup. And the older engines often seem to be better for this sort of
purpose than the newer ones.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
>With machines like this there is a saying, "If you need to ask....".
>Basically it's a large machine, larger than a 19" rack (only about 4.5-5
>feet tall though). IIRC, the power requirements aren't that bad, you
>should be able to run it off a dryer circuit (as long as the dryer isn't in
>use), and it's single phase.
Hmm - I know that lower-numbered 6000 CPU's had three-phase 208V
power supplies. At what point did they go back to single phase?
Not that a three-phase power requirement on a 6000 is a killer - they
actually don't suck very much current, so a electronic phase converter
on a dryer circuit is a *very* reasonable approach.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927