=============================================================================
ClassicCmp - The Classic Computers Discussion List
FAQ (Frequently Asked Questions) v1.2
Last Update: 4/16/97
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This FAQ is written with the primary purpose of making readily available
answers to the more common questions appearing on ClassicCmp. It is
Maintained by Bill Whitson <bill(a)booster.u.washington.edu>. The infor-
mation in this document has been gathered from a variety of sources but,
in general, the members of ClassicCmp should be credited for all contain-
ed herein. I have, of course, endeavored to be as accurate as is possible
and often failed ;).
If you have questions, comments, or corrections (always welcome) please
contact me at the address above.
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This FAQ has jumped 2 updates because I've been lazy about posting it.
Part 5.4 is new
Sections 6-9 are new.
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About ClassicCmp
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1. About the List
-----------------
1.1 What is ClassicCmp?
1.2 Why is ClassicCmp?
1.3 What's a Classic Computer?
1.4 Who runs this thing?
1.5 Don't you know you're duplicating what others have done?
2. Protocol and Etiquette
-------------------------
2.1 What can I talk about?
2.2 Can I talk about PCs?
2.3 Can I talk about Mini/MainFrames?
2.4 Can I post advertisements?
2.5 Can I ask people to give me their computers?
2.6 Can I ask for help fixing item x?
2.7 Where should I look before posting a dumb question?
3. Misc List Information
------------------------
3.1 How many subscribers are there?
3.2 How many subscribers use machine x?
4. ClassicCmp Resources on the Net
----------------------------------
4.1 Does ClassicCmp have a Web Site?
4.2 How come the Web Site is so ugly?
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Collecting
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5.1 Where can I find Classic Computers?
5.2 How much is machine x worth?
5.3 Will thousands of innocent machines be scrapped if I don't save them?
5.4 I just picked up a new machine. What should I do?
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Hardware and Media
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6.1 What's the best way to clean these dingy tan boxes?
7. Media
--------
7.1 What's a hard sector disk? What's a soft sector disk?
7.2 What's SS/SD, DS/DD, DS/QD, DS/HD, etc.
7.3 Can these formats be interchanged?
7.4 What disk sizes are there?
7.5 How do I take care of old media?
8. Component Failure Issues
---------------------------
8.1 Do EPROM's go bad?
8.2 How about ROM's, other chips?
8.3 How about capacitors?
8.4 Anything else?
8.5 So how do I backup all this stuff like you suggest?
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Software
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9.1 Where can I get a system disk for platform X?
9.2 What's the best way to back up my software?
=============================================================================
1.1 What is ClassicCmp?
It's a mailing list for the discussion of classic computers. Topics center
on collection (just hoarding), restoration, and operation. It is also an
appropriate place for stories and reminiscences of classic computers.
1.2 Why is ClassicCmp?
Uh, why not? There are lots of people who love these old machines and it
seems like a fun idea to get together and talk about them.
1.3 What is a Classic Computer?
Any computer that has not been manufactured for 10 years is a classic.
This definition is one I made up and it's entirely arbitrary. It seems to
work OK, so I've kept it.
1.4 Who runs this thing?
That would be me, Bill Whitson. I run this thing when I'm not busy being
a network admin at the University of Washington, SCUBA diving, playing
drums in punk rock bands, or drinking heavily. Oh yeah, I'm a 22 year
old, unmarried, childless, white, male living in the state of Washington in
the US. People ask you the strangest things when you run a listproc...
1.5 Do you know you're just duplicating work other people have done.
Damn straight. That's what the internet's all about. OK, guess I have to
update this too - I get a "reinventing the wheel" e-mail at least once a
week. If you show me another group of computer collectors that claims
a membership as large as this one I'll show you a group that must be
very hard to find. Obviously there are other groups of collectors and I'm
cheering them on - I don't see a problem with duplicating and reduplicating
lore that's quickly disappearing anyway.
2.1 What can I talk about?
Anything related to classic computers as defined above. There are many
people on this list that really know what they're talking about, so you might
want to check facts before you start shooting off messages (if you're easily
embarrassed).
2.2 Can I talk about PCs?
Yes. PCs which haven't been manufactured for 10 years. Even then be
aware that in many cases you would get a better response posting to PC
newsgroups.
2.3 Can I talk about Minis/MainFrames?
There has apparently been some misconception that this is a list for
micros only. You'll note I said "misconception".
2.4 Can I post advertisements?
Sure. As long as they're related to _classic_ computers. And, of course,
use your brain - don't spam.
2.5 Can I ask people to sell/give me their computers?
Sure. But you're not likely to get a very nice response. Mine, for example,
would be: Get your own f***ing computer! There are several people on
usenet who will vouch for this. See section 5 for info on how to find your-
self a computer.
2.6 Can I ask for help fixing item x.
Yes. Be aware that it may be difficult to help you fix things if you don't
have much knowledge of how computers work or of how to use basic
electronics tools (DMM, soldering iron, EPROM burner, etc). I'm no whiz
with this stuff and the little knowledge I have has come from asking
questions and then buying books to find out what "Simple... Just check
the voltage on the caps in the PS to make sure one of them isn't flaking
out!" exactly means.
2.7 Where can I look before posting a dumb question?
It might be a good idea to take a look at what's available in the Archive
section of the ClassicCmp web site (see below).
3.1 How many subscribers are there?
Around 230, fluxing daily.
3.2 How many subscribers use machine x?
Don't bother asking me. If you really want to know go ahead and post
to the list. I really don't know what having a number will do for you...
4.1 Does ClassicCmp have a web site?
Yep. http://weber.u.washington.edu/~bcw/ccl.html
4.2 How come the web site is so ugly?
How come a PET is so ugly? Who cares as long as it works?
5.1 Where can I find classic computers?
The best places seem to be thrift stores and swap meets. These are
closely followed by pawn shops and mom and pop computer stores.
The holy grails are electronics scrap yards - but they tend to be wary
of individual pick-and-choosers. Oh yeah - garage sales!
5.2 How much is machine x worth?
Precisely as much as you'll pay for it. Oh, you're selling it? Then,
precisely as much as I'll pay for it. Seriously, no one prices these any
more. I have an old Computer Blue Book that lists many classic
computers but the prices are just ridiculous. Some machines (Apple
Lisa's, old old Mini's, and unreleased prototypes) are starting down
the road toward their original selling prices.
5.3 Will 1000's of innocent machines be scrapped if I don't save them?
Yes. This is the impetus behind every collector's tireless and selfless
effort. Each machine we fail to save has it's gold parts mercilessly
hacked off and sold (just like rhino horns - and look at the rhinos).
The remainder is then sent to China to be made into bicycle spokes (you
probably think I'm joking). Save a computer! Act now! Remind your
wife of the rhino and cuter, furrier animals. It might work.
In all seriousness - there are a large (and growing) number of so called
"computer and electronics 'recyclers'" who take usable computers and
recycle them into "reusable scrap". Small amounts of gold, silver, and
platinum are extracted and the remainder of the material is generally
just marketed to less wasteful countries.
5.4 I just picked up a new machine. What should I do?
Don't power it up yet! All of the following should probably be done
before that power switch gets flipped.
Open the case - clean and visually inspect components. You're
looking for traces of smoke, water, corrosion, loose screws, blown
caps and resistors, etc. You can avoid a number of problems just
by taking a peek inside.
If you have the tools (and the machine is sufficiently rare) pull and
dump backups of all EPROMs, ROMs, and PALs.
Disconnect the power supply from the rest of the computer and
start it up on a "dummy load". A six volt headlight bulb has been
recommended as a convenient load. These should be available
>from any decent Volkswagen shop. Hopefully this will prevent frying
the rest of the machine with a flaky power supply. You may want to
check the voltage output before you do this as it could be no where
near the 5V average in micros. Even if you don't want to connect
a load it's still probably a good idea to power it up separately from
the computer for the first time. If you have a really rare beast it
may be worth powering up some of the key capacitors out of circuit
just to get them warmed up.
Now you can power it up. Assuming it works, take a blank disk,
format it, write some data to it, and read it back before using your
precious software with it, as a bad disk drive could really ruin your
day.
6.1 What's the best way to clean these dingy tan boxes?
Cases: It seems best to start gently with such old equipment. Try
soaking in a little water and dish soap and then scrubbing. This takes
care of most jobs. For removing stickers try mineral oil or Goo-Gone
(available at most hardware stores - in the US at least). If those
don't work, acetone can be good but, if overused, can do more harm.
For removing marker, almost any solvent is good (alcohol, naptha, etc)
but will definitely discolor or dissolve plastic if not carefully
applied. Lava soap is also good for removing marker but can smooth off
textured plastic. For removing sun or tobacco discoloring a product
called Purple Stuff available from auto parts stores (again, in the US
at least) seems to do the job almost effortlessly.
Connectors: For edge connectors a plain pink eraser seems good
for removing corrosion. Make sure to wipe the connectors with a
clean cloth after erasing on them though. There are a large number
chemicals on the market that "magically" remove corrosion from comp-
onents but I'm not anxious to promote any of them. For pin style
connectors a toothbrush and some softscrub or other mildly abrasive
cleaner do wonders.
Keyboards: I find a cycle through the dishwasher does a really nice
job on keyboards. Just be sure they're completely dry before you
put any power to them.
7.1 What's a hard sectored disk? What's a soft sectored disk?
We'll start with soft-sector since they're simpler to explain. On a
soft-sector floppy disk the information that marks where a sector
begins and ends is written to the disk by the computer (part of the
formatting process). This means that various computers can use
the same floppy disk types because the format of the disk is control-
led by the operating system.
Hard sector disks use a system of perforations in the media to mark
the beginnings and ends of sectors. This means that computers
which used hard sectored disks required the exact disk type they
specified rather than a generic soft-sector floppy. A number of
differently sectored disks were available - at least 10, 13, and 16
sector formats. 8 inch and 5.25 inch disks commonly used hard
sectoring. To my knowledge it was never used with 3.5 inch disks.
7.2 What's SS/SD, DS/DD, DS/QD, DS/HD, etc.
These all refer to the number of useable sides on a disk and it's
density (how "efficiently" the magnetic bits are pushed together).
SS/SD is a Single Sided - Single Density disk, the earliest available
type I believe. The storage afforded by a single density disk was
very small compared to today's standards. Single Sided disks were
popular because they were cheaper than DS and could be easily
modified with a hole punch into double sided disks. SD was followed
by Double Density which, amazingly, doubled the amount of storage
space. Double Density was followed by the extremely short-lived
Quad Density which doubled a DD disk. QD was short lived because
High Density was right on it's heels and nearly doubled disk capacity
again. DS/HD was as sophisticated as 5.25" disks became. 3.5"
disks have progressed as far as DS/EHD double-sided / extra-high
density.
7.3 Can these formats be interchanged?
Well, that may depend on what computer you are using, but in general
the following substitutions may be made:
Desired Format Substitute
---------------------------------------------------
Single Density Double Density
Double Density none reliably
Quad Density High Density
High Density none
Other substitutions may be made, but due to physical differences in
how the disks are made they are generally unreliable. It can almost
be guaranteed that data written to a proper density disk of poor quality
will last longer than data written to a good quality disk of the wrong
density.
7.4 What disk sizes are there?
Physically? There are 8 inch, 5.25 inch, and 3.5 inch as "standard"
disks. There are also some unique and/or short-lived sizes such as
3 inch disks used by Amstrad and 2 inch disks which were pioneered
for use in laptops and then quickly forgotten.
7.5 How do I take care of old media?
Step one is Back It Up! After that, make sure it's kept in a clean, dry,
temperature-controlled environment (I keep mine in a broken freezer).
With disks it seems important to keep them standing on end rather than
lying flat - the same goes for cassette tapes. I like to exercise disks
and tapes at least once every six months although I have no real
evidence that this has any positive effect. I have modified an old C64
floppy drive to simply spin when a disk is inserted and send large
stacks of disks through it on a regular basis just to make sure they're
not starting to stick up internally.
An exciting and somewhat recent development is that availability of
classic computer emulators that can make disk images of old media
on PC's and Macs. This seems to be a very good way to backup
disks since they will eventually go bad no matter how well we take
care of them.
The official line seems to be that floppy disks have a shelf-life of
approximately 10 years. With proper care many are lasting a lot longer.
8.1 Do EPROM's go bad?
Definitely. They apparently are considered to reliably contain data for
(on the outside edge) 15 years. This amount can be considerably
reduced if, for example, the sticker over the window has dried out and
fallen off. Luckily EPROMs were not used too extensively but they're
out there. An EPROM writer/reader is a relatively cheap investment
and an easy fix. Even if an EPROM has "forgotten" it's data it is still
fine for being "re-educated".
8.2 How about ROMs and other chips?
Things wear out. It's likely that even components which have not been
fried by catastrophic failure will simply start to die someday. ROMs can
be dumped to a file and re-written if they die. Other custom chips which
are all too common in micros will be far more difficult to replace. The
best advice is to stockpile these chips when you can - but someday even
unused chips will probably start to turn up bad. In this case the best
defense is to stockpile information in the hope of being able to modify
an existing component to meet your needs.
8.3 How about capacitors?
This seems to be another large concern, but rather than being an
unreplaceable component a capacitor will take your unreplaceable
components with it when it goes. It's a good idea to check out all the
caps in a system if you haven't fired it up in a while. Caps go bad
with time (even tantalum caps, apparently - although they are more
reliable) and should be replaced if they are suspect. It's unlikely that
it will be impossible to find a replacement capacitor as they are much
more standard electronic components.
8.4 Anything else?
Documentation: If there's anything which is entirely unreplaceable its
the docs for uncommon equipment. Once they're gone, they're gone.
I regularly pick up docs I find for equipment I don't have just because
I may someday. Paper will, of course. go bad over time but it will be
obvious and they will be easily duplicated.
Hard Disks: ST-251s, ST-502s, MFM, RLL... old hard disks are going
to go bad. Then they'll be gone. Theoretically, I suppose it's possible
to crack a hard drive and replace a dead bearing, realign, relaminate,
etc... but I've never heard of anyone doing these things in their base-
ment. Perhaps in another 5 or 10 years many of us will be experts at this.
8.5 So, how do I back up all this stuff like you suggest?
This answer will undoubtedly get longer as I learn more. The best ways
seem to be to dump the particular ROM (or whatever) using the approp-
riate equipment to a floppy disk (which most of this equipment allows).
Hi,
While I have the attention of Lisa owners with the other thread I
thought I may make this request...
I have owned a Lisa 2 for a number of years now, but unfortunately it
has a mostly broken power supply unit. Over this time I seem to have got
close to finding spares or schematics more times than I care to
remember, only to be let down at the last minute. (Sorry, sob story
over now.)
It is a complex beast and I don't have the technical know how to fix
the problem, but I do have friends, who are skilled electronic
engineers, who say they can do it with the schematics.
Has anybody got the schematics for a Lisa 2 power supply?
Failing this has anybody got a working spare they are willing to part
with? Or do you know of a cheap source of them?
Many thanks...
--
Kevan
Old Computer Collector: <URL:http://staff.motiv.co.uk/~kevan/>
I remembered a message here about pricing and video games yesterday.
Someone had an Atari 2600 (the new, revamped, black type) at the car boot
sale in Edinburgh yesterday.
He explained to me that this was a "games computer" with around 8 carts
(<sarcasm>lemmesee, Pacman, Ms. Pacman, Pole Position, etc. -- ooh,
rare</sarcasm>). The price: 20.00 UKP (around $30?). Surely, these people
are joking. I didn't even want to haggle for a new VCS.
Now, if it was the *OLD* type, I might have been interested (I don't
normally collect this stuff, but the old VCS has sentimental value -- I
played my first game of Space Invaders on one).
Unfortunately, at another flea market, another time and another country
(and anyway, the wench is dead), an original VCS was going for around $100,
with extremely common carts selling for as much as $25. Amazing. Almost as
expensive as the thing when it first came out. :-)
My theory for this is that game machines haven't changed all that much in
the last 20 years: still a box, still take carts (or CD-ROMs nowadays),
still have joysticks. What the heck, it must be worth something, right?
Whereas computers have changed so dramatically that your average car boot
sale joe will sell an old `computer keyboard' (probably a ZX-80) for
peanuts since it doesn't appear to have a monitor or a CD-ROM or Winblows
installed.
--------------------------- ,o88,o888o,,o888o. -------------------------------
Alexios Chouchoulas '88 ,88' ,88' alexios(a)vennea.demon.co.uk
The Unpronouncable One ,o88oooo88ooooo88oo, axc(a)dcs.ed.ac.uk
Whilst in a self-induced trance, Sam Ismail happened to blather:
>I think this would be a fun thing to do still. If anyone else is
>interested, speak up, or write to me directly via e-mail. Then we don't
>have to bother anyone else in the discussion with our silly little game.
>We could pick a date (a weekend) and then assign some sparse rules and
>then do it. It would be fun. Contact me if interested.
Actually, I think this would be a fun "silly little game" except in my case
the time frame needs to be improved *greatly*. Where I live, garage sales
haven't even started yet! (Why, you may ask... for some reason, people
don't want to set their "prized possesions" out in 2' of snow!)
What would be fun for me is if the contest ran for a month, or even the
whole summer... then those of use in the "boonies" might have a chance...
'cause for now, you win. Tough to enter a contest when they don't offer it
in your area!
Also, if it was over a month's span, then I might even be able to take a
road trip to a larger (read: civilized) area to do some scrounging... and
mebbe hit some thrift stores, as well.
How's this sound, folks?
"Merch"
--
Roger Merchberger | If at first you don't succeed,
Programmer, NorthernWay | nuclear warhead disarmament should *not*
zmerch(a)northernway.net | be your first career choice.
> ----------
> From: Alexios Chouchoulas[SMTP:alexios@vennea.demon.co.uk]
> Reply To: classiccmp(a)u.washington.edu
> Sent: Monday, April 21, 1997 5:44 AM
> To: Discussion re-collecting of classic computers
> Subject: Re: Collecting (was: On Generations of People and
> Computers)
>
| If mainstream Microsoft
| droids start collecting, we'll have to rescue old hardware
>from THEIR
| filthy claws as well.
> ----------------------------------------------------------------------
> ----
> Attention:
> [ ] Clueless Newbie [ ] Lamer [ ] AOLer
> [ ] Me-too-er [ ] Pervert [ ] Geek
> [ ] Spammer [ ] Grade School Dropout [ ] Nerd
> [ ] Fed [ ] Freak [ ]
> Scientologist
> [ ] Fool [ ] Jesus Krispy [ ] Anonymous
> Coward
> [ ] Rush Limbecile [X] Paranoid MS-Hater [ ] Ex-AOLer
>
> You are being contacted because:
> [ ] You said "me too" to something
> [ ] You posted a phone-sex ad
> [ ] You posted a local message in an international conference
> [ ] You posted a "test" in a newsgroup other than alt.test
> [ ] You started an off-topic thread
> [ ] You posted a "YOU ALL SUCK" message
> [ ] You brag about things that never happened
> [X] You posted a "Microsoft is out to get us" message
> [ ] Your sig/alias/server sucks
> [ ] Your writing skills do not even meet the low standards of Usenet
> [ ] You posted a jail-bait message
> [ ] You asked a ridiculous question
> [ ] You posted a con/scam/pyramid scheme message
> [ ] Your lack of a quote made your response incoherent
> [ ] You posted to more than four newsgroups
> [ ] You were imposing your religious beliefs on others
> [ ] You posted something really stupid/depraved
> [ ] You tried to blame others for your stupidity
> [X] You incorrectly assumed unwarranted moral or intellectual
> superiority
>
> To Repent, You Must:
> [ ] Invest in a dictionary/spell-checker
> [ ] Learn to correctly use your software/provider/bulletin board
> [ ] Give up your AOL account
> [ ] Try faking an interesting personality
> [ ] Pretend you are Trent Reznor
> [ ] Actually post something relevant
> [X] Shave your head
> [ ] Read the docs/FAQ
> [ ] Post your tests to alt.test
> [X] Limit yourself to 2 hours of WWF Wrestling per day
> [ ] Print your home phone number in your adverts
> [ ] Become a Satanist, sell your kids to Michael Jackson
> [ ] Send Bill Gates a love letter
>
> In Closing, I'd Like to Say:
> [ ] You're an idiot
> [ ] Bite me
> [X] Get a life
> [ ] Never post again
> [ ] I pity your dog
> [ ] Go to hell
> [ ] Your mother's so fat/stupid/ugly that etc...
> [ ] Learn to post or sod off
> [ ] Do us all a favor and crawl into some industrial machinery
> [ ] See how far your tongue will fit into the electric outlet
> [ ] All of the above
>
> end flame.
> ----------------------------------------------------------------------
>
>
>
>
I was just reading the FAQ and thought that I should add my two cents.
6.1 What's the best way to clean these dingy tan boxes?
Paper items:
About a year ago, I found an Osborne Starter Kit in a thrift store.
This is a ring bound manual and some audio cassettes to get a new
user started, packaged in a flat cardboard box, the kind with a glossy
surface. Well the box had been wrapped many times with that inch and a
half clear packaging tape to prevent it from being opened. I knew that
if I tried to remove the tape that I would remove most of the surface
of the box too.
Then I had an idea. I removed the manual and the tapes from the box
by cutting the tape around the edge of the box. And then I put the box
in the freezer for a few hours until it was nice and cold. I still had
to be careful removing the tape but the tape didn't stick to the box
as well as it did when it was warm. And it didn't leave any glue behind.
The one that I havn't licked yet is how to remove crayon price marking
from a paper diskette label or a book page without it smearing or bleeding
into the paper.
7.4 What disk sizes are there?
A floppy diskette is 8" in width.
A mini floppy diskette is 5.25" in width.
A micro floppy diskette is 3.5" in width.
And computers like the Amstrad CPC6128 and the Sinclair ZX Spectrum+3 use
a compact floppy diskette which is 3.15" or 8 cm in width.
I also have diskettes made by Nintendo (the word Nintendo is embossed
in the plastic) for the Nintendo Family Computer. I don't know what
they're called and I haven't measured one yet, but as I remember they
are just a little smaller than a micro floppy.
----------------------------------
My computer collection up on the web still needs a lot of work, but
I'm looking for suggestions about:
- the way it's laid out
- are the pictures too big to download quickly
- is there incorrect information
If you can help me out, my collection is located at
www.best.com/~dcoward/museum Thanks
----------------------------------
>>Is everyone else in their 20's and 30's? Anyone seriously outside of
>>this range?
I'm 210 years old in computer years.
=======================================================
dcoward(a)pressstart.com
Doug Coward
Senior Software Engineer
Press Start Inc.
Sunnyvale CA
=======================================================
At 10:10 PM 4/18/97 -0700, you wrote:
>>In a message dated 97-04-14 22:27:40 EDT, you write:
>>
>>> > >Is everyone else in their 20's and 30's? Anyone seriously outside of=20
>>> > >this range?
>>> >
>>I'm seriously outside of =20. more like =20 +25(next week).
>>
>>Lou
>
>Just a young man are you.
>
>Last week I turned 53.
>
> -Ron Mitchell
>
I turned seventy two about a month age!
Charlie Fox
Does anyone out there know much about the old PET 2001 machines?
I received a PET a couple of years ago, in which all of the 6550 SRAMs
were fried. I replaced them with the chips from another PET 2001 (one
with the miniature keyboard, from 1977) and the system worked fine.
Does anyone know how all of the memory chips could've been killed?
I tried them in various patterns in the sockets, and it does seem as if
all 16 of them are fried.
Anyway, is it still possible to get 6550s anywhere? And if not, is there
a replacement that could be used?
Even better: Can I simply replace the 6550s with another type of chip and
get more RAM in the system? Most of my software works in 8K, but I do
have some music files that require more. (I have one of those external
music boards that plugs into the cassette2 and user ports, that delivers
four voices.)
Now, another question. With that same PET, came an expansion board of
some kind. Its like a daughterboard, physically mounted on posts above
the motherboard, but connected via the memory expansion connector on the
side.
It appears (yes) to be a memory board, with 16 RAM chips on it. At least,
they look like they could be RAM chips, judging by the traces on the
board. However, I've never seen RAM chips with gold contacts and gold
plates on their backs before, as six of these chips have, so I'm wondering
if this could be more than just a memory board.
The board is dead, BTW. The PET won't operate with the board plugged in.
It just comes up with a screenful of garbage characters.
The board plugs directly into the PETs power supply, and then a cable
leads from it to the PET motherboard's power connector. There are three
large 470uF capacitors and two things that I guess are voltage regulators
(I don't know much about electronics :) ), so I'm guessing that this board
has its own refresh circuitry on it and it uses DRAM, but that could be
totally wrong. :)
Both connectors on the cable that leads from the expansion board to the
motherboard are noticeably burnt. In both cases, the burn marks surround
the pin that connects to the black wire.
The only identifying mark on the board is the text:
R 3014
rev.
C
COPYRIGHT 1978 R.C.Factor
Does anyone have any better guesses than me as to its function? (Can the
edge connector on the side of the PET be used for anything other than RAM
expansion?)
Doug Spence
ds_spenc(a)alcor.concordia.ca
Whilst in a self-induced trance, dcoward happened to blather:
> I was just reading the FAQ and thought that I should add my two cents.
And I was just reading this post, and can add some wisdom as well...
>7.4 What disk sizes are there?
>
> A floppy diskette is 8" in width.
> A mini floppy diskette is 5.25" in width.
> A micro floppy diskette is 3.5" in width.
The *first* micro floppy was 3" in width. Yes, you heard me correctly.
Amdek designed and built a SSDD 3" floppy drive around 1983-84 (or so...
I'll have to look) that used it's own style of media (and it was flippy,
unlike the 3.5" of today) and they interfaced it to and marketed it for two
computers that I know of:
The Radio Shack (Tandy) Color Computer, and
The Atari 800.
So far I've seen 2 Atari units for sale on the forsale newsgroups in the
last 9 months or so, and altho I've never seen the CoCo version (on sale or
anything) I have a color magazine ad advertising the system that I could
scan in if I ever find the time...
================
Also, in the grand naming scheme above, just *what* would you call a 2"
floppy? Yessireebob, a 2" floppy! I *own* one of these drives... they were
used in the Zenith MiniSport 8088-based IBM/clone laptop. Cute little
rascals... someday I'll take a pic or two and scan 'em in...
Specs: 2" floppy, 80 Track, DSDD 720K formatted storage capacity.
(I don't know the TPI or anything... may look into that if possible...)
I hope this helps to enlighten folks just a little bit more...
Have a Golfy Day!
"Merch"
--
Roger Merchberger | If at first you don't succeed,
Programmer, NorthernWay | nuclear warhead disarmament should *not*
zmerch(a)northernway.net | be your first career choice.
To fill a gap in the Heathkit section of my collection:
Heath (H10?) Paper Tape Reader/Punch unit.
Any out there???
-jim
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jimw(a)agora.rdrop.com
The Computer Garage - http://www.rdrop.com/~jimw
Computer Garage Fax - (503) 646-0174
