<Z-80, which was enjoying almost universal acceptance as the most widely
<applicable and easiest-to-use microprocessor available. Most of the popula
I could argue it was or it wasnt. ;) Keep in mind at that time I was
doing 8048, 8085, z80, 1802, 6100, sc/mp, TI9900, LSI-11, some 6502 and
6800. That does not include the uCOM4 (NEC 4bit) and uCOM75 (cmos high
end 4bit) parts.
<statements about it were pretty much on the money. Of course, the evolutio
<of the 64K DRAM made its refresh counter more or less useless, but the
Only some as a goodly portion still had 128 address row refresh (NEC4164
and About four others). But 64kDrams were really a year out due to price
in late 79 being rather high. (then design cycles for new products wer
9-18 months too).
<the Apple to accomplish the same thing. Meanwhile, Motorola was making a
<BIG mistake, abandoning the amateur and "small" users.
Yes! The 6800 if you had the 25$ big book you were an expert if you could
read. Later parts did come so cheaply supported.
<Since the evolution of the now-popular 'C' and PASCAL compilers for the
<8051-core micro's, I believe the popularity of this 25-year-old model has
<actually increased. The HLL's and the development of high-speed versions o
Yes it has but the code it not as dense as hand written. Then again with
the availability of LARGE ROMs/EPROM/EEPROM it may be development timeover
code density.
<'51-core user. I believe that it's as a consequence of that, that there ar
<now compilers for several truly "ugly" architectures, e.g. the PIC/SCENIX
Yes they were never a favorite for me but then again I could program them
as they looked like the 4bitters I used to work with.
<class of processors. There are also VHDL and VERILOG cores for several of
<the older architectures, e.g. 650x, available for those who prefer to
<"roll-their-own" which are also, though less well, supported with compiler
<and other tools.
If your need embedded 8051, 6502 and z80 are good choices.
<Again, Motorola seems to have been left behind at least with their smaller
<MCU's. I guess that's because of their reputation for spurning application
<which consume fewer than 100K parts per week.
Yep, seen that before.
Now the worst thing I've seen was the 8086/8 and its heirs. I really hated
writing code for it. The segmentation scheme was one horrid hack.
Allison
<> The point was apparently missed. Of course I can take a cmos z80 and
<blow
<> that out of the water using a 6 or 8 mhz clock.
<
<But because of the way the phases are used, a 2MHz 6502/65C02 is running a
<roughly the same rate (for comparable operations) as a 4MHz Z80.
Yes, the 6502 overlaps the instuction fetch and execute (mini pipeline).
The z80 is more classic multi-state machine. In the end the two parts are
roughly the same speed for their generation. IE: a 4mhz z80 does basic
operations in 1uS and 6502 at 2mhz is about the same. the difference is
any is when complex indexing or other tassks are discussed where the z80
has a better instuction set (though slower...more states) the 6502 uses
more small instructions(fast but many). In the end they do the same task
just different.
That supports the only logical conclusion... clock speeds dont count.
The full measure is instruction execution time. Which is why I used the
PDP-8 example as that machine used 1.4uS core yet it had a fairly high
effective speed.
Now to extend this to other older cpus there are some out there that were
just plain slow or due to their instruction set so awkward as to end up
being slow.
Allison
>I would also like to lay my hands on a programmer's console. It's one of
>the only things (besides hex-high core) that I'm missing.
Same here... the 8/A I recently got seems pretty fully loaded (I
haven't yet itemized what's in it), but the one thing it doesn't
have, and that I really really want is a programmer's console
for it...
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '@' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg |
+--------------------------------+-------------------------------------+
--- jeff.kaneko(a)juno.com wrote:
> Guys:
>
> I have discovered a PDP-8a in a scrapyard near my workplace.
> It has been outside for awhile; but if there are any salvable
> parts there, would anyone be interested?
But of course.
> BTW-- How do I get the front panel off without breaking
> anything?
Depending on the front panel style, if you see two 1/4" holes, one on either
edge, it may take an allen wrench. If the panel has no apparent tool access,
it's probably held in place by a pair of ball and socket joints on each side
which can get extremely tight if pressed on too hard and left to sit. There
are times when I think I'm about to bust the balls right off the backplace,
and sometimes I'm right. :-(
What's inside? What are you offering? At this point, I could even use a
new chassis as I have a full set of a mix of verified working and untested
boards (128kW MOS, RL8A, etc). I'm sure that the memory and disk I/O work;
I am not certain that my spare DKC8AA is any good. ISTR that about 10 years
ago I pulled it and set it aside for acting up.
I would also like to lay my hands on a programmer's console. It's one of the
only things (besides hex-high core) that I'm missing.
-ethan
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com
>>> There should be
>>>some plastic catches (or more likely the remains of same) on the PSU.
>
>>I've found that most half-inch tape seals have latches which are
>>quite amenable to being used as replacements for the original plastic
>>catches :-).
>Tim,
>I think I'm going to have to plead ignorant here. What are "half-inch tape
>seals"?
You know those 2400-foot, 600-foot, and other lengths of half-inch tape
that are used in 7-track and 9-track drives? The reels are commonly
enclosed in plastic straps with latches; the strap with the latch
is the "tape seal". I think "Tape Seal" may actually be a trademark
of Wright Line. The latch part usually has a plastic hook extending
>from it that you can hang the tape up by on a Wright Line tape stand
or cabinet.
There are non-Wright-Line tape seals with very different plastic
designs that serve the same general purpose, but are specifically
designed for auto-loading tape drives. These seem to be more
common in IBM shops.
--
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
You've got two tracks mixed up, I think. True, the Apple II was quite
plentiful in 80, but not in businesses the way it was in 82-83. I even had
several of them with people to man them as well. I hated the Apple but
loved the 6502. In the meantime, I noted that the RS Model 1 was a piece of
junk, and, in fact, so much of one that I never bought one, even for
experimentation, and I had nearly every other sort of box around the shop.
The Model 3 design my employer had contracted to him was paid for in late
'81. I saw several of them in friends' houses, none of whom had bought them
new, by the way, so they'd been on the market for a time in '82-83. We had
a really terrible blizzard on Christmas of '82 here, and I saw one in a
neighbor's house then. It was an early version but it was a model 3.
I'm aware there were plenty of Apples around since the one which was wheeled
in to the weekly 6502 Users' Group meeting by the chief guru was not even
attracting a second glance. A lot happened in the early part of '81, i.e.
Apple prices dropped for the first time, in an effort to retain market share
>from the now increasingly available though not yet particularly attractive,
either as a computer or as a budget item.
There's some more imbedded commentary below, if you're interested.
Dick
-----Original Message-----
From: Allison J Parent <allisonp(a)world.std.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 10, 1999 5:59 PM
Subject: Re: What if,... early PCs (was: stepping machanism
><The IBM entry into the PC market was in mid-1981, I think, and the Model-3
><was rushed to get out ahead of it. The Apple-II exlposion wasn't quite
><underway yet, but the handwriting was on the wall.
>
>No. By then the apple and trs80 were common as house flies. In fact in
>1980 we used Apples and TRS80s running a similar program for forcasting
>as they were in wide use around the shop. They were both in the market
>in terms of volumes nearing a 500k system each if not more by 1980.
The model 1 was quite common, but the model 1 was in too many pieces to be
of much interest to most folks. What's more, it was pretty weak-kneed. The
model 3 held out hope, though that was later dashed when the model 3 turned
out to be not much better.
>the PC wasn't an impact until 82 maybe 83. Memories and events seem to
>get compressed or expanded. I's even say the PC was not a serious
>contender till mid 83.
The initial impact of the PC was to get people to stop buying non-PC's for
their businesses. They were extremely costly at first, and didn't have a
few serious problems worked out. People had to mortgage their houses to buy
one (a basic PC on the gray-market cost nearly $2k).
>Allison
>
Hi,
I managed to borrow a hard drive with OS/2 warp on it from someone. I want
to copy it onto my own drive. How do I do this? I know that in DOS, I
would do a sys command to make the drive bootable. There is no sys command
here. What should I do?
--Max Eskin (max82(a)surfree.com)
On Apr 11, 10:20, Richard Erlacher wrote:
> Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit
51
> I have to disagree with your comparison of the 2 MHz 6502 with a 4 MHz
> Z-80A. My thought here is that the 4MHz Z-80 used in the conventional
way,
> had a memory cycle of 750 nanoseconds (3 clock ticks), while the 6502, at
> whatever rate, again, used in the conventional way, had a memory cycle of
> one clock tick. Now, some instructions involve several memory cycles,
but
> that was true of both processor families. What I often cursed, was that
the
> textbook application of the 650x core left memory available (idle) half
the
> time. That was a blessing up to a point (2.5 MHz to be exact) because it
> allowed for DRAM "RAS-precharge." The Apple and others like it proved
that
> at around 1 MHz, the 6502's memory could be used for an entirely separate
> purpose, e.g. video refresh.
I wasn't talking about precisely 2MHz vs 4MHz, just a ballpark figure (as
opposed to "about the same" or "about ten times" clock speeds). So, given
the rest of your message, I think we're in broad agreement. BTW, BBC
Micros have a 2MHz clock on the 6502, and interleaved video and processor
access quite happily in 1980. The video took care of the refresh
requirement.
> I believe there are entirely too many subjective, architecture-related,
> factors to allow an absolute comparison/contrast of the two processors.
Agreed :-) That's why lies, damned lies, and benchmarks are so much fun
:-)
> In my "gut" I still believe the 4 MHz Z-80 is about
> comparable to a 1.5 MHz 6502.
Well, that's not very far from what I wrote, is it? I was just pointing
out that although Allison seemed to imply that a 6 or 8MHz Z80 was much
faster than a 4MHz(? I haven't got the original message any more) 6502, I
believe that to be far from the case.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
I saw an interesting book at the library today about something called PICK
OS. I didn't get to look through the entire book, but I read enough to see
that it refers to directories as dictionaries. It seems to take a novel
approach, but I know nothing about it. Haven't even heard of it. Does
anyone here know more? Does anyone here have the PC version (mentioned in
the book)?
--Max Eskin (max82(a)surfree.com)
I have to disagree with your comparison of the 2 MHz 6502 with a 4 MHz
Z-80A. My thought here is that the 4MHz Z-80 used in the conventional way,
had a memory cycle of 750 nanoseconds (3 clock ticks), while the 6502, at
whatever rate, again, used in the conventional way, had a memory cycle of
one clock tick. Now, some instructions involve several memory cycles, but
that was true of both processor families. What I often cursed, was that the
textbook application of the 650x core left memory available (idle) half the
time. That was a blessing up to a point (2.5 MHz to be exact) because it
allowed for DRAM "RAS-precharge." The Apple and others like it proved that
at around 1 MHz, the 6502's memory could be used for an entirely separate
purpose, e.g. video refresh.
At one point in time, I went to some lengths to demonstrate the relative
performance capability, based on common applications, when the processors
were placed in an environment in which the primary constraint on the
processor's performance, hardware-wise, was the memory bandwidth. It turned
out to be a rather difficult comparison, because of the lengths to which one
had to go in order to utilize the memory bandwidth most effectively. The
Z-80's most difficult aspect was that its memory cycles were of different
lengths.
The 6502 could be interfaced quite easily by using an asymmetrical clock,
with a short Phase-1 (the period during which addresses and control signals
change) and a relatively long Phase-2, which is the cycle when I/O to
off-chip system-resources take place. This was straightforward until the
system design was adjusted for DRAMs, which were the most common problem of
that time. Both processors had problems with DRAM usage. The 6502, when
its clock was tweaked to make DRAM access most time-efficient required,
absolutely, that a cycle-stealing arrangement was used in order to support
refresh. This meant extra hardware.
However, the otherwise minimalist Z-80, which once was touted as supporting
DRAMs by generating a refresh cycle from time to time, required extra
hardware to modify its clock as well in order to allow for a long enough M1
cycle, and to allow enough time for the refresh to occur during its
allocated window. This meant even more hardware.
It turned out that all the things which the processors' designers had done
in order to make the two chips "efficient" became a problem when I tried to
implement each one in a way which was tailored to attain the most effective
utilization from what was then the most costly system resource, the main
memory.
In any case, what I determined was that the Z-80, in spite of its
complicated hardware requirement, was potentially the faster processor.
This was based on a comparison of the two in what I then considered an
application tailored to the most effective use of memory bandwidth. I also
quickly concluded that the 6502 would outperform it in an application where
memory demand was small enough to allow the use of SRAMS, because if the
fastest Z-80 available at the time (1981) was handed memories fast enough to
operate it at full speed with no wait-states, i.e. minimal hardware, the M1
cycle was still so short as to use the normal Phase-1 time of a 4 MHz 6502,
the memory cycle of which was a single clock tick as opposed to the Z-80's
three.
I believe there are entirely too many subjective, architecture-related,
factors to allow an absolute comparison/contrast of the two processors.
Being mostly a hardware-oriented type, I find the analysis adequate to
warrant the second conclusion above, though I've never been entirely
satisfied with the comparison I made based on their relative speed in the
execution of a BASIC program. The BASIC interpreters were different, and
the programs had to be "fiddled-with" in order to make them both run. The
difference was not overwhelming, so I've never been entirely comfortable
with the concusion. In my "gut" I still believe the 4 MHz Z-80 is about
comparable to a 1.5 MHz 6502.
Back in 1980, the Z-80 was definitely the wisest choice if you had to settle
on a single processor for carrying out useful business tasks, because the
Z-80 could run CP/M which had LOTS of such "useful" programs, thoroughly
debugged, most of which were entirely suitable for commercial use, and there
were significantly fewer useful-work programs for the 6502, which was more
popular in graphics-oriented systems because it could share its memory and
because its instruction set was apparently better suited for moving icons
around in a display memory as most game programs required.
Dick
-----Original Message-----
From: Pete Turnbull <pete(a)dunnington.u-net.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, April 11, 1999 8:35 AM
Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4
floppies)
>On Apr 11, 9:16, Allison J Parent wrote:
>
>> The point was apparently missed. Of course I can take a cmos z80 and
>blow
>> that out of the water using a 6 or 8 mhz clock.
>
>But because of the way the phases are used, a 2MHz 6502/65C02 is running at
>roughly the same rate (for comparable operations) as a 4MHz Z80.
>
>--
>
>Pete Peter Turnbull
> Dept. of Computer Science
> University of York
----------
> From: John Lawson <jpl15(a)netcom.com>
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: PR1ME 2550 Up and Running
> Date: Monday, April 12, 1999 10:11
>
>
>
> Well... it didn't hurt as much as I thought it was going to..
>
> I have just run "SHUTDN ALL" after two hours of playing with PRIMOS
> (on a DEC LA120 running at 300 baud... s-l-o-w...).
My first encounter with VMS was on a Vax 6310 using a Decwriter II at 300
baud. :^)
> I rescued this system about two months ago, and finally got tired
> of it taking up space.
Nice work, a Pr1me is on my want list too. Can you post a pic on web site
somewhere?
> And, apropos of the Pick discussions, this machine has INFORMATION
> loaded and running... haven't messed with it yet, tho..
On Tuesday, April 06, 1999 4:24 PM, Mike [SMTP:dogas@leading.net] wrote:
> My vacation/computer-rescue-mission has come to a close and there is now
a
> big honkin pile of trs-80 6000 and 16b toys on my living room floor. :)
> Several of them have broken this or thatsz but the first one I pulled, a
> 6000hd 15mhd, booted into Xenix 3.0.1 I think (Microsoft '84). the 68k
in
> it crashed after about 20min of xenix frolicking. She's resting now.
I'd
> like cc and tcp for this if anyone can help me out? I 'm sure some
parts
> will be available as soon as I figure out what I have. Software, give
me
> software or give me death.
>
> ;)
> - Mike: dogas(a)leading.net
>
Mike,
Nice haul...
A couple of weeks ago, I got a Model 2 and a Model 16 sans keyboards. Both
machines had been in storage for a long time and were absolutely filthy.
After careful disassembly, cleaning, and reassembly, the Model 2 returned
to life. Another list member has located a keyboard for me (thanks) so,
that one is complete. I haven't found a boot disk for it yet but, I'm sure
it'll work just fine.
Last weekend I opened up the Model 16 to see if it could be resurrected.
The hard drive had been previously removed but it looks like everything
else is there. After the ritual cleaning, I applied power to the computer
and promptly smoked the floppy drive. One of the traces on the PCB lit up
like a freakin Christmas tree. DAMN! I'm surprised it didn't blow a fuse or
something. I haven't looked at the drive too closely so, I'm not really
sure what happened there.
If it is a power supply problem, the whole machine could be history. I'm
hoping it was a problem with the floppy and didn't kill anything else.
I have not been able to get a trace on the CRT and really don't have the
enough tools to properly diagnose the problem. I did however notice the
filament on the CRT was glowing and the cooling fans were running. I
believe the fans get power from the 110AC primary and the filament could be
>from an unregulated source. So, this doesn't totally eliminate a Power
Supply problem. Can anyone tell me what voltages should appear on the PS
connectors?
Is there an easy way to determine if the processor is alive?
Unfortunately, I don't have a scope or logic probe :-(
If anyone can suggest a good source for a Logic Probe, I'll consider
buying one?
If I'm unable to get this thing working, I'll make the parts available. The
case and CRT are in really good condition so, don't trash any of the Model
16 parts yet. Between us, we should be able to put another one together.
Good Luck,
Steve Robertson - <steverob(a)hotoffice.com>
On Apr 11, 9:16, Allison J Parent wrote:
> The point was apparently missed. Of course I can take a cmos z80 and
blow
> that out of the water using a 6 or 8 mhz clock.
But because of the way the phases are used, a 2MHz 6502/65C02 is running at
roughly the same rate (for comparable operations) as a 4MHz Z80.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
There was another one I haven't seen in a couple of decades, called Allied.
I once worked for a subsidiary of another Allied Electronics, so they must
have been gone by then. Laffayette was a place where I bought audio
components, e.g. speakers, crossover networks, passive radiators,
grille-cloth, etc. Of course that was in the '60's . . . When the periodic
table was easy to memorize, . . . let's see, there was air, earth . . .
Dick
-----Original Message-----
From: Steve Robertson <steverob(a)hotoffice.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 10, 1999 9:01 AM
Subject: RE: Speaking of Tandy & TRS-80 (was: Re: What if,... early PCs
>On Saturday, April 10, 1999 10:16 AM, Charles P. Hobbs
>[SMTP:transit@primenet.com] wrote:
>>
>>
>> Does anyone remember a similar electronics store called "Lafayette"? They
>> were a big chain, probably not nearly as big as Tandy Radio Shack though;
>> I think they went under in 1980 or 1981
>
>
>I used to visit the Lafayette store in Ft. Lauderdale on a regular basis.
>IIRC this was in the Early 70's. The store primarily had audio gear, HAM
>equipment, and electronics components. Similar to the Radio Shacks of that
>time.
>
>As a matter of fact, I still have a Lafayette Stereo Amplifier at home. I
>used it for about 10 years then it quit working on one channel. Probably a
>bad output transister. I just never got around to fixing it...
>
>I don't recall ever seeing any digital stuff in the stores. Of course this
>was VERY early in the micro-processor development stage.
>
>Steve Robertson - <steverob(a)hotoffice.com>
>
Guys:
I have discovered a PDP-8a in a scrapyard near my workplace.
It has been outside for awhile; but if there are any salvable
parts there, would anyone be interested?
BTW-- How do I get the front panel off without breaking
anything?
Jeff
___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com/getjuno.html
or call Juno at (800) 654-JUNO [654-5866]
<I think that what occurred was that a group of list server messages were at
Try line breaks...PLEASE! the reso ot that line scrolls around the side of
the tube and under the desk. ;)
Allison
< I've got issue 2, Vol 1 of PC World dated Mar 83 .Compaqs Portable Comput
<was reviewed in this issue, and the reviewer mentions that IBM had introduc
<the PC 1 1/2 years earlier.
Thanks for the validation. At 46 Iwas there and am still young enough to
not be siffering from alzhimers. That and I have the same mags and adds.
;)
Allison
<I believe (guessing because I've learned memory doesn't serve as it once
<did) The load is two clock ticks and the indirect, indexed jump is five, s
<that's 3.5 microseconds, give or take a tick. it's less at 4 MHz, which i
<what the 65C02C is rated, though it readily will run at 4.9152 (24.576
<MHz/5) over a wide temperature and voltage range provided the clock is
<phased correctly. the divice-by five yields a 40/60 h/l which must be
<inverted to give a little longer phase-2 than phase-1.
The point was apparently missed. Of course I can take a cmos z80 and blow
that out of the water using a 6 or 8 mhz clock. Heck using a 1989 version
of the z80, the Z280 at 12.5mhz I can get the execution time way down. In
the time frame before 1982 (as a marker) there werent any 4mhz 650c02s and
there were 4mhz z80s and pdp-8s were still produced. In that context the
the example represent programming style rather that absolute speed as they
didn't vary that much over all to represent a great diffferece unless you
needed a characteristic that was specific to a given CPU.
I'm not slamming the 6502 or it heirs as it's also a very popular embedded
CPU still. For that fact so are the Z8 and Z80 heirs. Just from that it's
possible to conclude they all had desirable enough characteristics to keep
them in the running.
As a CPU the 8051 is ok, I use it. As a controller it's without question
a popular part still. But as a general purpose cpu, it's a really bad
C or Pascal compiler host/target.
Allison
Max Eskin wrote:
>I saw an interesting book at the library today about something called PICK
>OS. I didn't get to look through the entire book, but I read enough to see
>that it refers to directories as dictionaries. It seems to take a novel
>approach, but I know nothing about it. Haven't even heard of it. Does
>anyone here know more? Does anyone here have the PC version (mentioned in
>the book)?
>
>--Max Eskin (max82(a)surfree.com)
>
I have never played with PICK, but I have played with Prime "Information"
which is sometimes described as a PICK like operating system. I have a PC
version somewhere but in that form it is not a true OS. It is started as a
DOS application.
As someone else has said, not much use except for multi-user database
applications. The PC version is only a toy.
It was a 16 button keypad, with numbers 1-9, decimal point, and math
operators and two others I couldn't make out. Could someone tell me
what these keys were?
There's a pretty slick controller for ISA by Lark Associates which is
capable of lying to the PC in a way which actually convinces it you have two
physical drives. This makes using such large beasts much easier. I've not
been able to get good mileage out of my Miniscribe 9760 or my Maxtor 8760
since it ( the controller ) gave up the ghost. My WD controllers won't help
with making it old-bios-compatible.
Dick
-----Original Message-----
From: jpero(a)cgocable.net <jpero(a)cgocable.net>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 10, 1999 8:20 PM
Subject: Re: Micropolis 1518 Jumper Settings
>Date sent: Sat, 10 Apr 1999 20:46:00 -0500
>To: jpero(a)cgocable.net
>From: Jeff Kaneko <jeff.pat(a)mindspring.com>
>Subject: Micropolis 1518 Jumper Settings
>
>Hi Jeff and to cc follows:
>
>>
>> Attached is all of the information that I have; I haven't been able to
try
>> this because I'm stuck without a capable ESDI controller.
>
>Thanks! But same old hat again, it's same thing you see on the
>blue planet's website.
>
>There are few ESDI controllers that can do 24MHZ and *MUST*
>able to do up to 4096 cylinders. Nice thing about all ESDI
>controllers for Peecees, LBA built right in for greater than 528MB!
>
>> Looks like you should set for 512 bytes/sector, 83 spt, *hard* sectored.
I
>> wish I knew that Ultra 12f-24's were so damned rare . . .
>
>Really? What about it and why it's bit rare?
>
>And I really beg to anyone on this list to pool their experiences to
>"pull" up the ESDI performance because I'm getting subpar
>performance for a "high" end hd like 1538 with 71 sectors (1518 is
>83 sectors) both hds should have screamed instead of plodded
>along. About 600KPS out of that 1538, yuk. I got over 800kps on
>that same controller with a Miniscribe 3180E on that paltry 36
>sectors.
>
>Is there's a controller card that does much better than this Ultrastor
>12F24?! Oh, I've one computer based on EISA.
>
>Oh, anyone knows of same HDAs that uses SCSI interface board
>in place of ESDI, I want to know what model it shares same HDA
>for each? 1518 and 1538.
>
>>
>>
>> Jeff
>
>Wizard
referring to your questions regarding the execution time
>
>Execution time for an 8E (1973) would have been under 8uS if both
instuction
>used indirect addressing. As written it would be 7.6uS. Now the 6502 at
>2mhz would have done it in what?
>
I believe (guessing because I've learned memory doesn't serve as it once
did) The load is two clock ticks and the indirect, indexed jump is five, so
that's 3.5 microseconds, give or take a tick. it's less at 4 MHz, which is
what the 65C02C is rated, though it readily will run at 4.9152 (24.576
MHz/5) over a wide temperature and voltage range provided the clock is
phased correctly. the divice-by five yields a 40/60 h/l which must be
inverted to give a little longer phase-2 than phase-1.
I've imbedded a few comments in the text below.
Dick
-----Original Message-----
From: Allison J Parent <allisonp(a)world.std.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 10, 1999 5:58 PM
Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4
floppies)
><I knew somebody woudl come up with a good example. That 6809 code is
><probably the closest thing I've seen in a micro. The 8051 uses a similar
><approach, pointing to the table with the datapointer and uses the
>
>The 8051 is very ugly in other places.
It has a sufficiently varied instruction set that you don't really have to
use what you don't like. Perhaps you can take comfort in the fact that it's
been around since the early '80's and is still the most popular
architecture out there. What's more, it's not nearly as ugly as the PIC
architecture.
>Then there are the NEC uPD 78xx series that are similar in register layout
>to z80 but code wise, not close. They have a table lookup instructions for
>that exact task. They are targetted as rom based controllers and code
>efficientcy is a requirement but often controller don't need to preocess
>the kinds of things a PC (or other general purpose computer) would.
>
>The z280 has a load address inscrtuction that makes the setup for an
indexed
>jump easier.
>
>The PDP-11 did it on one instuction but it has some very powerful
addressing
>modes. Indirection and indexing are natural to that part.
>
>However in CPUs righer in register than the 6502, the task would be done
>far differently. It's a different programming style and it does impact
>code structure. For example a set of operations that can be done requiring
>multiple (say a dozen) 16bit parameters to be passed are easily done on
>even 8080 but the 6502 has to do that as indexed list in ram and pass
>the pointer to the list if you want to be efficient. It's possible to
>structure a problem such that any cpu looks good or bad. Generally an
>application is far more than a trivial few instructions.
>
>Look at the PDP-8 which is both register poor and has an instruction set
>that small is far from adaquate to describe. Yet it performs tasks
>efficiently in small amounts of core that some cpus can't.
>
>The 6809 example would be in PDP-8...
>
> / enter here with uart data
> DCA pindex / store index value at pindex
> JMP I,INDEX / indirect jump via index (could have been a JMS, jump
> / subroutine!)
>
>Execution time for an 8E (1973) would have been under 8uS if both
instuction
>used indirect addressing. As written it would be 7.6uS. Now the 6502 at
>2mhz would have done it in what?
>
>< They (DEC) did make the uVax-II as a chipset for interfacing to their
><BI-bus, I believe, so that might qualify as well. The DEC chipset probabl
><didn't sell for what a 6809 costs, even the faster part, and certainly not
><the $0.86 I last saw on the 4MHz Rockwell 65C02.
>
>?????? UvaxII was not for interfacing the BI, that was a dedicated
chipset.
>The uVAXII was a single chip (extended FPU and DMA were companions).
UvaxII
>was only remotely related to BI bus. The statment doesn't parse.
>
><I'm not surprised that it was in the 6809 that this instruction came up.
><The 6809 showed lots of promise at first, but once it was in hand, one
><clearly could see that it would be MUCH easier going with the MC68008 if
on
><had to use an 8-bit bus. I never had the opportunity to write in a
>
>the 6809 was a bridge part while waiting for the 68K. Still it was a good
>part.
I found them both (6809 and 68K) to be a disappointment. I guess there was
too much wait, and it wouldn't have mattered what they put out.
><high-level language for the 6809, but I was told it should have been quite
><easy to write a high-quality efficient compiler for it because of its
><repertioire of instructions and addressing modes. I turned out literally
>
>Nearly as good as the PDP-11. FYI both the 6809 and the 68k had heavy
>PDP-11 and vax influences.
>
>
>Allison
>
Date sent: Sat, 10 Apr 1999 20:46:00 -0500
To: jpero(a)cgocable.net
From: Jeff Kaneko <jeff.pat(a)mindspring.com>
Subject: Micropolis 1518 Jumper Settings
Hi Jeff and to cc follows:
>
> Attached is all of the information that I have; I haven't been able to try
> this because I'm stuck without a capable ESDI controller.
Thanks! But same old hat again, it's same thing you see on the
blue planet's website.
There are few ESDI controllers that can do 24MHZ and *MUST*
able to do up to 4096 cylinders. Nice thing about all ESDI
controllers for Peecees, LBA built right in for greater than 528MB!
> Looks like you should set for 512 bytes/sector, 83 spt, *hard* sectored. I
> wish I knew that Ultra 12f-24's were so damned rare . . .
Really? What about it and why it's bit rare?
And I really beg to anyone on this list to pool their experiences to
"pull" up the ESDI performance because I'm getting subpar
performance for a "high" end hd like 1538 with 71 sectors (1518 is
83 sectors) both hds should have screamed instead of plodded
along. About 600KPS out of that 1538, yuk. I got over 800kps on
that same controller with a Miniscribe 3180E on that paltry 36
sectors.
Is there's a controller card that does much better than this Ultrastor
12F24?! Oh, I've one computer based on EISA.
Oh, anyone knows of same HDAs that uses SCSI interface board
in place of ESDI, I want to know what model it shares same HDA
for each? 1518 and 1538.
>
>
> Jeff
Wizard
----------
> From: Max Eskin <max82(a)surfree.com>
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: PICK OS
> Date: Sunday, April 11, 1999 6:30
>
> I saw an interesting book at the library today about something called
PICK
> OS. I didn't get to look through the entire book, but I read enough to
see
> that it refers to directories as dictionaries.
IIRC, it is a dedicated O/S for use with a database system. Sort of a
bootable database program for want of a better description.
I (briefly) owned a Fujitsu computer that had PICK installed, it came out
of a public library and was a very solid box, that weighed a LOT. (It had
a ups built into it!) Fujitsu bought it off me! True! They were still
supporting some in service and wanted some parts, offered me twice what I
paid for it. (I rang them to get some info on the machine and they called
back an hour later with a cash offer.)
Never had more than a cursory look at the O/S, but I gather it's quite good
at what it does, but it doesn't do much else. Multi terminal time share
system. TV station I used to work for also had a PC based Pick System,
the logging program (used to create the "logs" actually a plan of the order
and length of programs that re to be put to air) ran on that and nothing
else it seems...
>It seems to take a novel approach,
That's a fair description. It seems to be dedicated to just one task. I
think there are other things it can do, but it's fairly limited...
That's the limit of my knowledge, others on the list will doubtless know
far more...
Cheers
Geoff Roberts
VK5KDR
Computer Systems Manager
Saint Marks College
Port Pirie, South Australia
geoffrob(a)stmarks.pp.catholic.edu.au
On Sat, 10 Apr 1999 22:17:56 -0400 jpero(a)cgocable.net writes:
>Thanks! But same old hat again, it's same thing you see on the
>blue planet's website.
Uh, okay. Micropolis being out of buisiness really makes things
tough for owners of these drives.
>> Looks like you should set for 512 bytes/sector, 83 spt, *hard*
>> sectored. I wish I knew that Ultra 12f-24's were so damned rare . . .
>
>Really? What about it and why it's bit rare?
Well, for one thing, Ultrastor is out of business, also. It doesn't
look like they made too many of these 24MHz controllers (most of the
ones I see offered for sale will not do 24MHz), and to make matters
worse, individuals who *do* have them either won't sell, or want
and arm and a leg for them.
>And I really beg to anyone on this list to pool their experiences to
>"pull" up the ESDI performance because I'm getting subpar
>performance for a "high" end hd like 1538 with 71 sectors (1518 is
>83 sectors) both hds should have screamed instead of plodded
>along. About 600KPS out of that 1538, yuk. I got over 800kps on
>that same controller with a Miniscribe 3180E on that paltry 36
>sectors.
>
>Is there's a controller card that does much better than this Ultrastor
>12F24?! Oh, I've one computer based on EISA.
Well, I know of only two other *solid* possibilities: The OMTI/SMS
8640, and the DTC 6282-24. ANother one is iffy: the WD 1009.
I have gotten mixed reports on this one: SOme sources say it will
do 24MHz no problemo. Some say no way Jose. I've been looking for
all of these. Zip. Nada. (Unless I was willing to fork over $90
to a dealer for an 8640.
>Oh, anyone knows of same HDAs that uses SCSI interface board
>in place of ESDI, I want to know what model it shares same HDA
>for each? 1518 and 1538.
Uh, I know what you've got in mind, but you will not be able to
swap the "interface" board to a different HDA. Reason is, when
these are made, the board is 'married' to that HDA using jumper
settings and stuff (the ones with glyptol dripped on them so
you can't remove them by accident). Each one is different (it has
something to do with the servo head, I think).
Jeff
___________________________________________________________________
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In a message dated 99-04-10 22:26:30 EDT, you write:
> Does anyone have a copy of the Apple version that they would want to sell
> (or copy)? I also have a font/image pack for the PC version, if anyone
> wants a copy (I'll have to check them to see if they're good or not first,
> though.
I've version 2.1 (?) on 3.5 disks that could be copied, although i've heard
of possible copy protection issues. i presume copy ][+ 9.0 could do it.
anyone know?
Hi!
I Used to have a Commodore 128 that had GeoWorks on it (I think it was
actually GEOS, or something like that). I also have a box and font/graphics
set for the PC version or GeoWorks. I've also heard that there was a
version of it for the Apple // series.
Does anyone have a copy of the Apple version that they would want to sell
(or copy)? I also have a font/image pack for the PC version, if anyone
wants a copy (I'll have to check them to see if they're good or not first,
though.
--
-Jason Willgruber
(roblwill(a)usaor.net)
ICQ#: 1730318
<http://members.tripod.com/general_1>
<The IBM entry into the PC market was in mid-1981, I think, and the Model-3
<was rushed to get out ahead of it. The Apple-II exlposion wasn't quite
<underway yet, but the handwriting was on the wall.
No. By then the apple and trs80 were common as house flies. In fact in
1980 we used Apples and TRS80s running a similar program for forcasting
as they were in wide use around the shop. They were both in the market
in terms of volumes nearing a 500k system each if not more by 1980.
the PC wasn't an impact until 82 maybe 83. Memories and events seem to
get compressed or expanded. I's even say the PC was not a serious
contender till mid 83.
Allison
Hi Daniel,
----------
> From: Daniel T. Burrows <danburrows(a)mindspring.com>
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: seagate st1280n
> Date: Saturday, April 10, 1999 6:18 PM
>
> Try http://www.seagate.com/support/disc/specs/st1480n.shtml
> Dan
thanks a lot,
that was what i needed. (Haven't see that they are the same besides of the
capacity ;-))
cheers,
emanuel
one good thing about being a hamfest vendor is that you get to see what's for
sale the previous night and free food. so far, i bought an apple /// with
profile. what's even better is that i got a bunch of documentation and system
disks with it like business basic, device driver manual, apple access ///,
apple writer ///, owner's guide, apple backup, utilities, profile drivers and
demos. even got the owners manual and a copy of castle wolfenstein in
original packaging. time to make backups of all this stuff. mostly pc items
for sale, but did see a few portable PS/2s and some S100 bus cards. are they
worth picking up?
also bought 10 TI99 carts and the speech box earlier today.
In a message dated 99-04-10 20:46:42 EDT, you write:
> This is possibly too new for this list, so please excuse me if I offend
> anyone...
>
> I was wondering if any of you might have a copy of PCMICA drivers, such as
> might have been shipped with a modem or other card?
>
> I'm in the process of resurrecting my NCR Safari, but the only drivers
> that came with it are a simple memory card driver/formatter.
>
> Thanks...
> <<<John>>>
some drivers are just point enablers which basically get the card working and
that's it. it also depends on what type pc cards you want to use. or, you
could try installing pcdos7. it has phoenix pc card drivers that can be
installed.
>Just out of curiousity, which fuse is missing?
I was rushed, so I didn't really notice the rating. It was the
middle one on the cover latch side (left side of the case as you
look at the front panel)
>Another thing. I trust you have the little jumper plugs in the 3 pin
>mate-n-lock sockets on the power supply? If not, the machine won't power
>up. These sockets are _not_ the same as the ones on a PDP11 power
>controller. You need to short the middle pin to one end pin on one socket
>and the middle pin to the other end pin on the other socket.
Aha... There is only one of those in (that I remember)...
Which one is shorted which way (or is it sufficient to have one
short one way and the other to short the other way?)
Sorry, I haven't looked at the printset yet... that's the reason
for the stupid question...
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '@' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg |
+--------------------------------+-------------------------------------+
Hi!
This is possibly too new for this list, so please excuse me if I offend
anyone...
I was wondering if any of you might have a copy of PCMICA drivers, such as
might have been shipped with a modem or other card?
I'm in the process of resurrecting my NCR Safari, but the only drivers
that came with it are a simple memory card driver/formatter.
Thanks...
<<<John>>>
I didn't get a chance to take pictures of it today, but I did take a
look at my 'long' 8/e... The cover is solid. I didn't take a look at
the hinged side, but the latch side has hexagonal holes for venting.
The tolerences seem very tight between the metal of the case and some
very exposed wiring terminals...
As for my 8/e, although it hums when I apply power, nothing happened
when I turned it on... I checked the fuses, and one of them is
missing... I'll try it again when I replace the fuse (I really should
have checked that to begin with...)
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '@' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg |
+--------------------------------+-------------------------------------+
> <Does anyone remember a similar electronics store called "Lafayette"? They
...
> They were nothing like TANDY.
...
> They were long gone by '79.
>Correct...nothing like *Tandy*, but quite similar to Radio Shack ...
>perhaps with a better mail order line, IIRC and a bit more oriented
>towards parts and radio. The last one I saw was in Sunnyvale/Santa
>Clara (here in the Bay Area) around 1980/1981.
Lafayette similar to Radio Shack? Bite your tongue...
I remember lafayette as having better quality stuff than Radio
Shack, regardless of what I was looking for... I remember going
over there all the time with my father when I was young...
If you wanted something built to last, you got lafayette. If you
wanted something built out of cheap plastic, you went to Radio
Shack...
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '@' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg |
+--------------------------------+-------------------------------------+
>> Does anyone know where I might be able to buy some thin black foam filter
>> material, to replace the stuiff that was used on my Teral computers?
>> These systems have a large fan that draws air into the computer, and
>> the intake air goes through this very thin filter, in order to capture
>> large particles such as lint.
Check your local DEC scrapper. The back doors from SA800's, TU8x, and many
system doors had large sheets of it held in place with Velcro like strips.
I save them from all the systems that go through here for replacement usage.
They are about 1/2 inch thick.
Dan
I came across an odd board in the dumpster at work today. Hopefully
one of you might recognize it. It appears to be some sort of bubble
memory board.
Details:
Small board, approx. the size of a 5.25" floppy drive board
2x40-pin Berg headers at one end
2x36-pin edge connectors at the other
2 very small pushbuttons
3 LEDs labelled:
ERR
EN
RUN
Obvious chips:
ROM labelled "RCB1.1"
Z80A
Intel D7220-1
Intel 7110A-1 bubble memory module
Lots of 74LS-family chips
Markings:
Bubbl-tec
division of PC/M, Inc.
Copyright 1984
PC/M INC.
R-II-AM-BUBBL-A
Anybody recognize this one?
<<<John>>>
----------
> From: Zane H. Healy <healyzh(a)aracnet.com>
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: OT: copying OS/2 Warp
> Date: Saturday, April 10, 1999 2:41 AM
>
> Last I checked OS/2 Warp V3 and V4 were both available. I've heard a new
> version is actually in the works (despite the fact I used to be a huge
OS/2
> fan I find that a little hard to believe).
AFIK, that's no new version, but a major cleanup.
( A huge OS/2 fan for a long time too)
cheers,
emanuel
<logic, but it's beed field-modified (I guess) to take the LED modules in
<the lamp sockets. The preheat resistors have been cut out.
<
<No idea if this was done by DEC or not (it was done before I got the
<machine), but it is another possible frontpanel.
Common field change but not from or by DEC.
Allison
<And on mine this board:
<
<>M837 MC8E Extended Memory and Time Share Control
<
<Is right in front of the RFI shield (and core stack) Sort of "all
<components of the memory subsystem together" kind of thing :-)
Where the 837 goes was less important. Generally the rule was terminator
in last slot and timing generator in the first one behind the FP. Then
the RFI shield close as possible to the firrst core card set. Other than
that there were few rules.
allison
I have a Variac here that I need help connecting up.
The terminals on it are as follows:
O 2 4 O
| |
wwwwwwwwwwwwwwwwwwwwwwwwww
/ \
O O
<--><------100V------><-->
20v | 20v
O
The "2" and "4" are what is labelled on those terminals.
The "O" are the terminal connectors.
The "w"'s are windings as depicted on the terminal panel.
The panel also shows the voltages as depicted. I'm assuming the output is
2 and 4. But what is the input?
The 20v sections seemingly say that you can tap off of them to get some
combination of 20V, 120V or 140V?
Please help!
Sellam Alternate e-mail: dastar(a)siconic.com
------------------------------------------------------------------------------
Don't rub the lamp if you don't want the genie to come out.
Coming in 1999: Vintage Computer Festival 3.0
See http://www.vintage.org/vcf for details!
[Last web site update: 04/03/99]
<I rewired the plug on J3 to supply 5V at pin #3 (rather than going to the
<voltage regulator board) and both backplanes are now functional! Running
<Allison's worm program with the memory in back and the CPU and stuff in fro
Congrats!
Here is the lineup from mine and the recommended board layout.
54-09668 KC8FL PDP-8/F Programmer's Console
M8330 KK8E Timing board, replaces M833
M8310 KK8E Major register control
M8300 KK8E Major registers
M837 MC8E Extended Memory and Time Share Control
*space
M8650 KL8E Asynchronous Data Control (current loop or RS232)
M8652 KL8JA Terminal Control (UART based, double buffered)
*space
M849 KK8E RFI shield
G111C MM8EJ 8K Memory sense/inhibit
G619A MM8E Memory stack (B,M)
G227C MM8E Memory X/Y drivers
*space
M8320 KK8E Bus loads
Reminder, core runs warm and likes cooling.
Allison
<Too bad it's wrong.
It misses a few details bit it is essentially correct. Do research before
you indite the document.
<It makes it seem as if there was a box that was designated PDP-8/E and it
<had a particular configuration that was retired until the introduction of
<new box with the designation of PDP-8/F. This isn't supported by the eviden
No. read the whole FAQ to get the full picture. that was an excerpt.
<What really happened, and I have several independent confirmations of same
<is that the PDP-8/E system evolved into the PDP-8/F in a series of steps.
<Depending on the date code the machine was configured differently.
Yes and sorta. the 8E was the large box and remained as the "big version".
As a cost moderating measure the smaller 8m/f versions were created for
more limited expansion and with a lower basic cost.
<The evolution vectors were as follows:
< Module updates - example M833 - M8330, M831 - > M8310
Bug fixes. early in the 8E life and nearly predating the later omnibus 8s.
The original designs had poor margins and too much green wire. Even later
ones have green wire.
< Chassis updates - Long box, single OMNI BUS
< Long box dual OMNI BUS
< Short box single OMNIBUS Linear PSU on side.
< Short box single OMNIBUS Switching PSU in
Rear version replaced the really broken side mounted PS version. The
switcher was not the best design as it was fairly new technology.
< Front Panel Updates: Diode logic + 8v LAMPS
Early 8Es only. Driven by manufacturability.
< TTL logic + 6v LAMPS
Bulk of production and the common verison in the 8E
< TTL logic + LEDs in lamp sockets
Never made, it was a field third party retrofit.
< TTL Logic + LEDS
8F/M pannel later in design than the 8e v2.
< PSU updates - Long linear PSU
< Short linear PSU
< Short Switching PSU (types A and B)
Not updates litereally differnt products with overlapping production lives
save for the two switchers.
<At some point in this evolution some marketroid decided to change the name
<from 8/e to 8/f. The OEM version of this platform was called the 8/m and
Sorry no! the 8E remained in production and the 8f was the short 20 slot
machine and aimed at lowering the cost for those that didn't need/want
38 slots.
<included an optional limited function front panel (although all 8/M's I've
<seen so far had the programmers panel but that's only about a dozen so who
<can say)
The 8M was a fairly standard menu machine with the limited function panel.
It's options included a full function pannel (if you were a volume customer
custom colors and board mixes).
<I happen to have an 8/e that is:
< Short box
< 6v LAMPs plus TTL front panel
< Side mount PSU
That is not an 8E, it a frankenmonster in a 8m crate.
<I recently picked up an 8/e chassis that had the dual OMNIBUS backplanes.
That is an 8E.
<It is this one that doesn't have a cover. It may have been mounted in a
<desk, I don't know (it also didn't have a front panel but I can use my
<other 8/E front panel with it)
The 8e was the model with the long linear PSU on the side and the dual
omnibusses.
<My guess is that the evolution of the 8/E was driven by the introduction o
<the 11/20 since these changes seem have occurred between 1970 and 1972. Al
No. the two were entirely differnet development and had the common thread
of newer low cost TTL available.
<8/E's with date codes prior to 1970 appear to be the diode front panel
<type, All 8/E's after 1972 appear to be either 8/F's or 8/Ms (until the 8/
<came out).
8Es were 1970 introduction. Parts will have datecodes up to a year older
than that.
<The 8/M and 8/F are primarily differentiated by different inserts/color
<schemes, electrically they appear to be identical. The solder mask of the
<front panel says "8/E"
The same pannel was used for all. It was an assembly level options that
set them apart.
Since parts were swapable there were a lot of variations due to parts being
moved as needed to maintain systems or make working ones.
The omnibus series of PDP-8s were all driven by lowering costs and product
improvements. Even the later 8As were KK8e cpus (m8330/8310/8320/8300).
The actual 8A CPU (kk8a?) was a hex module.
Allison
Please see imbedded comments below.
Dick
-----Original Message-----
From: Allison J Parent <allisonp(a)world.std.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 10, 1999 1:44 PM
Subject: Re: What if,... early PCs (was: stepping machanism
><It would be well to get the timelines aligned. The model 1 was of 1977
><vintage. The model -3 was worked up in the late '70's before Apple got it
><juggernaut rolling. Radio Shack had a real chance to make the
microcompute
>
>Model 1 (base trs80) was 1977 (mid year). I was part of the start up in
>the computer depot repair and computer store startup.
That's what I recall, as well.
>The next machine did not ship until after august 1979! I was there up to
>that point. Actually I think it was the 1980s(or 1980!) that the next
>version of the TRS80 family shipped.
The IBM entry into the PC market was in mid-1981, I think, and the Model-3
was rushed to get out ahead of it. The Apple-II exlposion wasn't quite
underway yet, but the handwriting was on the wall.
>The motly collection of parts... For years RS ment surplus parts in plastic
>bags and the late 70s was sort of their weaning. Except the purchasing
>mindset was there.
>
>If anything can be said... they were one of the few that didn't go broke
>shipping computers.
That's why they'd have been a force to be reckoned with if they'd ever
shipped anything really decent.
>Oh, and Apple shipped their machine the same year as the TRS80. so they
>represent the state of the art for 1977 for cost vs tradeoffs.
>
>Allison
>
>
Hello, is the Q-bus pinout on line? I've got an extender card and I'd like
to know if it was compatible or not. Also a pointer to the printset for the
PDP-8/e H724 PSU would be good, I've got one that is half dead (fortunately
it is the back half so with the computer in the front half it runs!)
--Chuck
> There should be
>some plastic catches (or more likely the remains of same) on the PSU.
I've found that most half-inch tape seals have latches which are
quite amenable to being used as replacements for the original plastic
catches :-).
>BTW, one of the few pieces of poor design in this machine is that you
>have to take the left side rackmount rail off the box before you can get
>the PSU out. This means you have to take the entire (heavy) machine out
>the rack before you can remove the PSU.
If you use short 10-32x1/4" screws on the left rail, it's a lot easier to
take the PSU out. (I thought everyone shortened these screws!)
With the original screws (3/4"), it is possible to get the PSU in and out
with the rail attached, but it is quite difficult and requires that the
PSU be inserted at a rather awkward angle.
--
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
At your local discount store, you should be able to find some fairly large
scouring sponges, I've found that these work adequately as filters,
provided you put a layer of porous cloth over the downstream side to catch
the finest particles. If you're fortunate enough to find the really fine
ones, the cloth isn't needed. These come in 1/4" thick postcard-sized
sheets, which I usually cut up anyway, so give these a try and see if they
meet your needs.
Dick
-----Original Message-----
From: Lawrence LeMay <lemay(a)cs.umn.edu>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 10, 1999 2:33 PM
Subject: source for foam filter material
>Does anyone know where I might be able to buy some thin black foam filter
>material, to replace the stuiff that was used on my Teral computers?
>These systems have a large fan that draws air into the computer, and
>the intake air goes through this very thin filter, in order to capture
>large particles such as lint.
>
>After 22+ years, that foam is nothing more than dust.
>
>I would need something almost 5 inches wide, that i could then trim to
>the proper shape.
>
>-Lawrence LeMay