Hi All,
I got this from a friend of mine. You can see there are still lots of
good reasons to keep a real plotter around. So save that plotter!
Joe
>
>A little while back a friend of mine (little bit of a collector, he
>has a Basis 108 and a DEC Pro 350, and some VAXen that he used to use)
>was starting to get into slide photography and going through his
>father's collection of slides (mostly having to do with the NYC subway
>system and like things in other cities). He decided he wanted to
>print on photo slide mounts; handwriting them doesn't work for him
>because he has crappy handwriting.
>
>So we spent some time at Fry's looking at inkjet printers, and decided
>the paper paths were too contorted -- no way to get a slide mount
>through there, let alone the sort of cardboard carrier we thought we'd
>need.
>
>We thought about it a while and decided that a plotter would be the
>way to go. Of course, who makes plotters in this day of cheap color
>inkjet printers (with expensive ink cartridges)? So I went to the
>next Computer Recycling Center sale and picked up a somewhat grungy
>7550A for $10 and passed it along to him. He bought some pens on
>eBay, worked out some HP-GL, hacked up a pen and an extra-fine
>Sharpie, and put together some bits of cardboard to make a carrier for
>a few slide mounts, and he was all set.
>
>So I guess they still have their uses. His only complaint is that the
>7550 takes up too much table space. I guess I'm keeping my eyes open for
>an 7470 or 7475 with RS-232 interface.
>
>
--- Phil Clayton <musicman38(a)mindspring.com> wrote:
> I would cast my vote for the Kaypro I have one in my office that runs with a
> nice continous demo program that I wrote in BASIC...
Care to share your demo? I've got a Kaypro 2 I picked up at the last Dayton
Hamfest (and a spare Tandon TM-100-2 double-sided drive to perhaps upgrade
with, should I care to plunk down the cash for a new boot ROM that supports
double-sided disks).
-ethan
===
Infinet has been sold. The domain is going away. Please
send all replies to
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__________________________________________________
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Bid and sell for free at http://auctions.yahoo.com
That 7550 is quite a bit "more" plotter than the smaller 74xx ones. It's
too bad the table is so small . . .
Dick
-----Original Message-----
From: Joe <rigdonj(a)intellistar.net>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, September 02, 1999 8:29 AM
Subject: HP plotters
>Hi All,
>
> I got this from a friend of mine. You can see there are still lots of
>good reasons to keep a real plotter around. So save that plotter!
>
> Joe
>>
>>A little while back a friend of mine (little bit of a collector, he
>>has a Basis 108 and a DEC Pro 350, and some VAXen that he used to use)
>>was starting to get into slide photography and going through his
>>father's collection of slides (mostly having to do with the NYC subway
>>system and like things in other cities). He decided he wanted to
>>print on photo slide mounts; handwriting them doesn't work for him
>>because he has crappy handwriting.
>>
>>So we spent some time at Fry's looking at inkjet printers, and decided
>>the paper paths were too contorted -- no way to get a slide mount
>>through there, let alone the sort of cardboard carrier we thought we'd
>>need.
>>
>>We thought about it a while and decided that a plotter would be the
>>way to go. Of course, who makes plotters in this day of cheap color
>>inkjet printers (with expensive ink cartridges)? So I went to the
>>next Computer Recycling Center sale and picked up a somewhat grungy
>>7550A for $10 and passed it along to him. He bought some pens on
>>eBay, worked out some HP-GL, hacked up a pen and an extra-fine
>>Sharpie, and put together some bits of cardboard to make a carrier for
>>a few slide mounts, and he was all set.
>>
>>So I guess they still have their uses. His only complaint is that the
>>7550 takes up too much table space. I guess I'm keeping my eyes open for
>>an 7470 or 7475 with RS-232 interface.
>>
>
>>
>
On my Ampro Little Board (the original one) on which I have a small hard
disk, though this is by no means limited to the hard disk, software loads
VERY fast as well. It's no coincidence, I believe, that this one has the
Kaypro format as an optional diskette format. The difference, I belive is
the way data is stored on the diskette. If you have the right combination
of sector skew and data block size, tansfers to/from diskette are quite
fast. What's more, since CP/M systems didn't normally attempt to do all the
crazy stuff that DOS attempts to do with its BIST/POST firmware, there's
less to wait for. I think one will be disappointed with the real
performance of the typical 4 MHz Z-80 if it's evaluated in an
I/O-independent way, since we've become accustomed to much faster
processors.
Nonetheless, turning the machine on and having the prompt waiting for you by
the time the monitor is warmed up enough to show the image is quite a treat.
With one of those 1.25" tall 3-1/2" drives, my Ampro boots up CP/M in a
second or two. It's amazing!
Dick
-----Original Message-----
From: Phil Clayton <musicman38(a)mindspring.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, September 02, 1999 7:44 AM
Subject: Why is CP/M faster than DOS
>After reading all the comments on CP/M computers a comment was made that
CP/M
>is a faster OS that DOS.. I have found this to be very true.
>My Kaypro 1X boots up in 5 seconds, and loads MBASIC in about another 5
>seconds, also
>executes the same BASIC code faster than on my XT.
>
>Now on my old Compaq XT, it takes about 30 seconds just for the hardware to
>powerup,
>then another 20 seconds to boot to a DOS prompt, then another 15 seconds to
>boot BASIC.
>
>So can some of the experts here tell me why CP/M is so much faster ?
>
>Phil...
>
>
>
>
After I wrote this remark I got to thinking . . . the model I was dogging
was a flatbed not quite the right size for "B" format but had analog inputs
rather than RS-232 or HPGL. It was a 72-something, but my aging memory
can't produce the "something" as it once did. Several fellows I knew had
snagged them and I spent literally weeks with each of them trying to make
them perform repeatably. They looked and smelled solid, but didn't behave
that way. Even when they were more or less operational, the pen speed was
very slow.
The 74xx series, by way of contrast, was more or less like a real plotter
though it was just a toy . . . sort of a stopgap while they developed a
useable printer with which to do the same thing. The 75xx models actually
behaved like real plotters. That tray-fed tabletop 7550 was the smalles in
this series, IIRC, but it had eight pens and could plot quickly and
accurately as could its bigger bretheren. There are some folks who were
sorry to see these dinosaurs pass, but anyone who's had to wait 45 minutes
for one to plot a "D"-sized drawing will tell you the ink-spitters are a
gigantic improvement.
Dick
-----Original Message-----
From: Eric Smith <eric(a)brouhaha.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, September 02, 1999 1:49 AM
Subject: Re: HP DraftMaster I
>Joe <rigdonj(a)intellistar.net> wrote:
>> Sounds like a HP 7221 plotter with paper feed. I have one of them and a
>> 9874 that's similar but has a HP-IB inteface. Someone dropped the 9874 on
>> one corner and bent the whole thing out of kilter. I've tried everything
>> but I can't get it to feed paper right. The framne is too heavy to try
and
>> straighten out. Perhaps if I took it to someone that has a puller for
>> straightening car frames .....
>
>I think you must be referring to the HP 9872. They sold basically the
>same plotter as three models:
>
>HP 7220 - RS-232 serial, compact binary language
>HP 7221 - RS-232 serial, HP-GL, same hardware as 7220 but with different
ROMS
>HP 9872 - IEEE-488 (HP-IB), HP-GL
>
>Different letter suffixes denoted the generation of the plotter, and
whether
>it had the roll feed (e.g., 9872 A/B/C without, and 9872 S/T with). Early
>generations had four pen stalls, and later ones had eight.
>
>Note that these were the first HP-GL plotters, and the language evolved
>some minor differences that prevent some modern software from working with
>them. I built my own serial-to-488 box to use with mine, and my firmware
>tweaks the HP-GL when necessary.
>
>"Richard Erlacher" <edick(a)idcomm.com> wrote:
>> God be thanked, it's not at all like that miserable piece of junk! If id
>> hadn't said HP on it, nobody with more than two grey cells would have
taken
>> one home.
>
>I can't believe you'd say that about this series of plotters, which were
>very well-engineered and solidly built flatbed plotters. Are you
>sure you're not thinking about the 7225, or the much later "consumer"
>grit-wheel plotters such as the 7470 and 7475?
please see embedded comments below
thanx
Dick
-----Original Message-----
From: Joe <rigdonj(a)intellistar.net>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Wednesday, September 01, 1999 7:16 PM
Subject: Re: HP DraftMaster I
>At 09:00 AM 9/1/99 -0600, Dick wrote:
<snip>
> I know. AFTER you bought it you found out that you needed all kinds of
>optional I/O ROMs and the like to make it work.
>
Actually, it was working perfectly about 2 minutes after I replaced the
parts on the serial I/O board. Now probably only one was defective, but I
replaced them all. There aren't many.
>
>> Nowadays, there's nobody there who'll even talk about them.
>
> Yeap.
>>
>>If you want to test the thing thoroughly, you'll have to get some of the
<snip>
> Sounds like a HP 7221 plotter with paper feed. I have one of them and a
>9874 that's similar but has a HP-IB inteface. Someone dropped the 9874 on
>one corner and bent the whole thing out of kilter. I've tried everything
>but I can't get it to feed paper right. The framne is too heavy to try and
>straighten out. Perhaps if I took it to someone that has a puller for
>straightening car frames .....
>
God be thanked, it's not at all like that miserable piece of junk! If id
hadn't said HP on it, nobody with more than two grey cells would have taken
one home.
>
> These machines will feed the appropriate amount, but don't
>>mind wasting paper, i.e. they feed the 36"-wide paper 14-15" for a
portrait
>>'A'-size form, wasting most of the paper. That was the reason I got the
>>single-sheet version. I don't need it to run all night unattended, but I
do
>>have to pay for the paper. You'll see that's not cheap.
>
> I always use mine if single sheet mode. BTW any idea where I can find a
>roll of paper for it? I only have a small amount of paper left and I'd
>like to have a roll to go with it.
>
>
>That may explain
>>why the drawings in most manuals are so difficult to read, having been
>>reduced from already-too-small drawings.
>>
>>The manuals may still be available somewhere, but I would get right on
>>trying to find them if I were you.
>
> I have a PRETTY GOOD bunch of plotter manuals. In fact, I have a good
>bunch of all of the HP computer and calculator manuals. I grab everyone
>that I can get my hands on! What model plotter do you have?
>
Well, the manual set for mine (HP7585B) weights just short of 25 lbs and
costs about $500 to duplicate because of the half-tone schematics and other
drawings, which won't Xerox at all readably.
>
> I made the purchase of my plotter
>>contingent on complete manuals, so they were included. That became a
>>condition after I found that Martin Marietta, after buying 20 or so of
these
>>still hadn't received a complete set of manuals even though each plotter
was
>>supposed to come with them.
>
> Boy! Does this bring back memories! When I was working in Canada for
>Martin Marietta we could never got any of the drawings and other documents
>from MM in the US. I keep calling and they kept telling me that they had
>been sent. In fact some of them were sent three times with multiple copies
>everytime. I finally got the name of the guy that they were sent to in
>Canada and I went found him. It turns out that he kept one copy of
>EVERYTHING that went through his office. I checked the next office that
>handled the stuff and they did the same thing. So did the next office. And
>the one after that! As it turns out the handling people kept everything and
>the ones of us in engineering never got the stuff that was supposed to be
>coming to us. I think that was SOP for MM!
>
>>
>>If you have access to a Windows box with AutoCad 12 on it (I don't have a
>>later version to try this) you should be able to put it through its paces,
>>as that has an internal plotter driver which operates independently of the
>>one in WIndows. I've had no luck at all getting the Windows driver to do
>>anything. I suspect (after watching the lights on the breakout box) that
>>there is some incompatibility in the way they work their handshaking.
>>Perhaps the '488 port will work for you, if you've got one with drivers in
>>your system.
>
> Well I'm using a HP 7550 on the PC so it may be more compatible than
>your older model. But I think you need more than a null MODEM cable to make
>the plotter work. I have a manual with the cabling schematics somewhere
>and I think the HP requires more of the pins to be connected than most
>serial devices do. I'll look for the cabling drawings if you want them.
>
The 7550 was an earlier, and much smaller, version from the same family. I
briefly had one but found the pens not to be interchangeable with my 7585,
and was too cheap to stock two sets of pens. For 'B' size, as th 7550 does,
I use an HP1120C printer.
> Joe
>
Hello Classiccmp.
I recently acquired a nice, rust-free, mostly-original 11/45 from
an old lisp hacker in Los Altos Hills, CA. He told me that it had been
running the last time he'd powered it up, which was in 1984 IIRC, but
sadly, something has gone awry and it won't run now, though it seems to be
close. Here's a brief summary of its status:
It was originally a five-rack system with each rack containing the
controllers for the housed peripherals. The bus was chained through to
each rack on a BC05 and terminated with an M930. I only took the
processor and the TU-10 racks, so to make troubleshooting easier, I
reduced the system to only the CPU and memory boxes (memory is a 220KB
box from Monolithic Systems that has unibus in and out). The processor
has 12 KW of core as well, so I guess I could cut the bus down a bit more
for the purpose of debugging.
Mode of failure is such:
I powered up the shortened system and the front panel lights lit
[excitement]. Then I tried to examine some memory locations via the
panel, but when I hit HALT, the RUN light stayed lit. I tried every
combination of switches I thought was appropriate, but the RUN light
wouldn't go off. (Sounds like a simple bus error, really.) Upon
realizing that something was amiss, I decabled all the power connectors
>from the logic and tested the voltages, which, surprisingly, were all
about 6%-9% above spec (and I'm not too sure that my VOM is accurate even
though it's analog). I didn't readjust the voltages, but reconnected the
power cables to the logic boards and retested the voltage levels. All
stayed about the same except for the -15VDC. It dropped to about 2V. Same
reading on both -15V regulators, by the way, and they seem to be connected
to different areas of the backplane, but I'm not sure. There seems to be
a high-pitch squeal (that sound of a laboring regulator) coming from
somewhere in the power supply cluster, but there's no smoke or crackling
sounds. I don't remember noticing the squeal with the power cables
disconnected, but that may be a subconscious hope and not a fact.
So that's my predicament. I don't have much time to mess with
this beautiful old girl, so I hope someone here can increase my repairing
efficiency.
Help me save this great piece of computing history. In return,
I'll at least give you an account on it if I get it to the point where
it'll run 2.9BSD or V7. I have SMD interfaces and disks, etc and
everything else I need (except a DELQA) to get it hooked up to the net.
Thank you in advance.
jake
I don't know how common they were, but most 8" floppy drives seem to have a
built-in provision for them. The most I've seen is the 33-hole 32-sector
format, but the drives with sector-separators on them had jumpering for 8,
16, and 32-sector formats.
Unfortunately, the controllers which operate on hard-sectored formats seem
to be like hen's teeth. If your system knows what to do with these, then
you're in luck.
Does your system read your data diskettes after you've booted from the
hard-sectored boot diskette?
Dick
-----Original Message-----
From: Doug Spence <hrothgar(a)total.net>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Wednesday, September 01, 1999 2:43 AM
Subject: 16-sector disks?
>Hi,
>
>How common are 16-sector hard sectored disks?
>
>I found some disks for my AES 7100, and that's what they are (17
>holes!).
>
>Unfortunately, the only Software disk I found only boots part way. The
>other disks are Data disks, and they give me an error when I try to boot
>from them. <s>
>
>But at least now I know that the screen works. :)
>
>--
>Doug Spence Hrothgar's Cool Old Junk Page:
>hrothgar(a)total.net http://www.total.net/~hrothgar/museum/
>
Hi,
How common are 16-sector hard sectored disks?
I found some disks for my AES 7100, and that's what they are (17
holes!).
Unfortunately, the only Software disk I found only boots part way. The
other disks are Data disks, and they give me an error when I try to boot
>from them. <s>
But at least now I know that the screen works. :)
--
Doug Spence Hrothgar's Cool Old Junk Page:
hrothgar(a)total.net http://www.total.net/~hrothgar/museum/
