The felt pad that presses the floppy disk into the r/w head fell off my
RX01 (or whatever dual floppy drive is actually inside a DECmate model
III (a late edition of 6120-based PDP-8).
Has anyone tried to do that repair? What did you use for replacement,
self-adhesive felt material?
cctalk-request at classiccmp.org wrote:
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>
> Today's Topics:
>
> 1. Re: 5" floppy?. (Jules Richardson)
> 2. Re: 5" floppy?. (Sridhar Ayengar)
> 3. Re: 5" floppy?. (Sridhar Ayengar)
> 4. HP3000 (Mike Loewen)
> 5. Re: HP3000 (William Donzelli)
> 6. Re: HP3000 (Mark Davidson)
> 7. Re: HP3000 (William Donzelli)
> 8. Re: Help with Shugart SA801 8" floppy with 230v 50 cycle
> (feldman.r at comcast.net)
> 9. Re: 5" floppy?. (David Griffith)
> 10. Re: 5" floppy?. (William Donzelli)
> 11. Screwheads; was 5 floppy?. (Chuck Guzis)
> 12. RE: Help with Shugart SA801 8" floppy with 230v 50 cycle
> (dwight elvey)
> 13. Re: 5" floppy?. (Dave McGuire)
> 14. RE: Help with Shugart SA801 8" floppy with 230v 50 cycle
> (Chuck Guzis)
> 15. RE: 5" floppy?. (dwight elvey)
> 16. Re:Screwheads, was: 5" floppy?. (Chuck Guzis)
> 17. Re: AT&T 7300/3B1's (was: Re: Who is vintagecomputermuseum?)
> (micheladam at theedge.ca)
> 18. Re: AT&T 7300/3B1's (was: Re: Who is vintagecomputermuseum?)
> (Gordon JC Pearce MM3YEQ)
> 19. Re: AT&T 7300/3B1's (was: Re: Who is vintagecomputermuseum?)
> (Lance Lyon)
> 20. IDE <-> MFM, was > Re: AT&T 7300/3B1's (was: Re: Who is
> vintagecomputermuseum?) (emu at e-bbes.com)
> 21. Re: The Day the Infant Internet Uttered its First Words
> (Steve Maddison)
> 22. RE: Help with Shugart SA801 8" floppy with 230v 50 cycle
> motor... (ROBO5.8)
> 23. Re: AT&T 7300/3B1's (was: Re: Who is vintagecomputermuseum?)
> (Jules Richardson)
> 24. Re: Help with Shugart SA801 8" floppy with 230v 50 cycle
> motor... (Jules Richardson)
> 25. Mystery paper tape reader (Tobias Russell)
> 26. MITS Disk Boot Loader manual (Richard A. Cini)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 25 Nov 2008 17:25:48 -0600
> From: Jules Richardson <jules.richardson99 at gmail.com>
> Subject: Re: 5" floppy?.
> To: General Discussion: On-Topic and Off-Topic Posts
> <cctalk at classiccmp.org>
> Message-ID: <492C897C.1080407 at gmail.com>
> Content-Type: text/plain; charset=ISO-8859-15; format=flowed
>
> Fred Cisin wrote:
>
>> It sure is easy to slip into off-topic mechanical griping.
>>
>
> Yeah, funny how there's a lot of interest overlap between vintage computing,
> old cars, and engineering (and that it says in the "to" field of this message
> that the list is for "General Discussion: On-Topic and Off-Topic Posts") - but
> let's not go there, huh? ;-)
>
>
> J.
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 25 Nov 2008 19:04:06 -0500
> From: Sridhar Ayengar <ploopster at gmail.com>
> Subject: Re: 5" floppy?.
> To: General Discussion: On-Topic and Off-Topic Posts
> <cctalk at classiccmp.org>
> Message-ID: <492C9276.8000809 at gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Tony Duell wrote:
>
>>> Even computer companies - people that should know better, make
>>> mistakes when talking about floppy disks. Last week I was in a Staples
>>> store (American office supply store chain), and saw a Memorex 3 1/2" USB
>>> floppy drive, the package stating clearly that it supported "1.44mb
>>> double sided and 720k single sided diskettes". >
>>>
>> Well, calling it mb (millibyte) is clearly wrong. And the value of
>> 1.44Mbytes assumes you take 1Mbyte as 1000*1024 bytes, which is downright
>> crazy.
>>
>
> Actually, doesn't mb imply "millibit", and mB is "millibyte", with Mb as
> "megabit" and MB as "megabyte"?
>
> Peace... Sridhar
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 25 Nov 2008 19:06:26 -0500
> From: Sridhar Ayengar <ploopster at gmail.com>
> Subject: Re: 5" floppy?.
> To: General Discussion: On-Topic and Off-Topic Posts
> <cctalk at classiccmp.org>
> Message-ID: <492C9302.40404 at gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Gordon JC Pearce MM3YEQ wrote:
>
>> (once again, sorry Jay)
>>
>>
>>> My favourite has to be Torx. I have never had any problems with those.
>>>
>> Oh I have... <grumble>Bloody Volkswagens with their stupid 5-lobed
>> Torx-like brake caliper bolts, that you can't even get drivers for from
>> VW without ordering them from Germany...
>>
>
> My Audi uses triple-square for that kind of stuff.
>
> Peace... Sridhar
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 25 Nov 2008 20:01:42 -0500 (EST)
> From: Mike Loewen <mloewen at cpumagic.scol.pa.us>
> Subject: HP3000
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
> Message-ID: <Pine.LNX.4.64.0811251950490.22596 at cpumagic.scol.pa.us>
> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
>
>
> Where have all the HP3000 systems gone?
>
> Between 1986 and 1988, I worked on a whole slew of HP3000s, from the
> Series III to the Series 70. They were popular in the business
> environment, especially in COBOL shops. Where did they end up? You can
> find loads of DEC equipment on Ebay, even IBM System 34, 36 and AS/400s,
> the occasional HP1000, but the only HP3000 I recall seeing in recent years
> was a single Model 37.
>
>
> Mike Loewen mloewen at cpumagic.scol.pa.us
> Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
>
>
> ------------------------------
>
> Message: 5
> Date: Tue, 25 Nov 2008 20:16:45 -0500
> From: "William Donzelli" <wdonzelli at gmail.com>
> Subject: Re: HP3000
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
> Message-ID:
> <e1d20d630811251716q468c96f4s9ab6b8a98cecdd43 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
>
>> Between 1986 and 1988, I worked on a whole slew of HP3000s, from the
>> Series III to the Series 70. They were popular in the business environment,
>> especially in COBOL shops. Where did they end up? You can find loads of
>> DEC equipment on Ebay, even IBM System 34, 36 and AS/400s, the occasional
>> HP1000, but the only HP3000 I recall seeing in recent years was a single
>> Model 37.
>>
>
> You answered your own question.
>
> DEC made loads of minis (PDP and VAX).
> IBM made loads of minis (S/34 and S/36).
> IBM made extra sized loads of AS/400 minis (more than any other minicomputer).
> HP did not make loads of 3000s.
>
> I think it is a simple population thing.
>
> --
> Will
>
>
> ------------------------------
>
> Message: 6
> Date: Tue, 25 Nov 2008 17:27:42 -0800
> From: "Mark Davidson" <mdavidson1963 at gmail.com>
> Subject: Re: HP3000
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
> Message-ID:
> <d17c35610811251727u5ec8860ayd6474c43da58e5f3 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> On Tue, Nov 25, 2008 at 5:16 PM, William Donzelli <wdonzelli at gmail.com> wrote:
>
>>> Between 1986 and 1988, I worked on a whole slew of HP3000s, from the
>>> Series III to the Series 70. They were popular in the business environment,
>>> especially in COBOL shops. Where did they end up? You can find loads of
>>> DEC equipment on Ebay, even IBM System 34, 36 and AS/400s, the occasional
>>> HP1000, but the only HP3000 I recall seeing in recent years was a single
>>> Model 37.
>>>
>> You answered your own question.
>>
>> DEC made loads of minis (PDP and VAX).
>> IBM made loads of minis (S/34 and S/36).
>> IBM made extra sized loads of AS/400 minis (more than any other minicomputer).
>> HP did not make loads of 3000s.
>>
>> I think it is a simple population thing.
>>
>> --
>> Will
>>
>
> I subscribe to the 3000 mailing list, and there seems to be one other
> complaint... licensing the OS. I am no expert on the matter, but I've
> gotten the impression that HP can be a real bear to deal with when it
> comes to licensing the OS for users. It simply can get too expensive
> for a hobbyist to run MPE...
>
> Trust me, I'd love to have a small 3000 at home and if one ever shows
> up, I'll snap it up if I can. They just seem to be pretty rare on the
> used market.
>
> Mark
>
>
> ------------------------------
>
> Message: 7
> Date: Tue, 25 Nov 2008 20:52:06 -0500
> From: "William Donzelli" <wdonzelli at gmail.com>
> Subject: Re: HP3000
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
> Message-ID:
> <e1d20d630811251752r7c21a151ge4ceec709310254c at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
>
>> I subscribe to the 3000 mailing list, and there seems to be one other
>> complaint... licensing the OS. I am no expert on the matter, but I've
>> gotten the impression that HP can be a real bear to deal with when it
>> comes to licensing the OS for users. It simply can get too expensive
>> for a hobbyist to run MPE...
>>
>
> A complaint, yes, but really has nothing to do with why 3000s are so
> scarce. Really, it is hard to beat the IBM AS/400 group for being
> disagreeable when it comes to licenses.
>
> I think DEC spoiled us.
>
> --
> Will
>
>
> ------------------------------
>
> Message: 8
> Date: Wed, 26 Nov 2008 02:41:19 +0000
> From: feldman.r at comcast.net
> Subject: Re: Help with Shugart SA801 8" floppy with 230v 50 cycle
> To: cctalk at classiccmp.org
> Message-ID:
> <112620080241.25527.492CB74F00042AA6000063B722007621949DD2020E030B040A00 at comcast.net>
>
> Content-Type: text/plain
>
> For small pulleys, check out a hobby shop that deals in radio controlled model airplanes and cars. For small gears, try www.nwsl.com. They also have small drills, bolts, and metal rods (e.g., 1.5mm x 6"). In England, try http://www.ultrascale.co.uk/ for small gears.
>
> Bob
>
> ------------------------------
>
> Message: 9
> Date: Tue, 25 Nov 2008 18:45:30 -0800 (PST)
> From: David Griffith <dgriffi at cs.csubak.edu>
> Subject: Re: 5" floppy?.
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
> Message-ID: <Pine.GSO.4.55.0811251843380.22711 at helios.cs.csubak.edu>
> Content-Type: TEXT/PLAIN; charset=US-ASCII
>
> On Tue, 25 Nov 2008, Chuck Guzis wrote:
>
>
>> I once read an interview with the son of inventor Henry Phillips (an
>> Oregon native) and he maintained that it wasn't the original design
>> (US Patent 2046343) that was at fault, it was primarily the fault of
>> ASC for cheapening the manufacturing process by relaxing
>> specifications--and the propagation of inferior tools. Indeed, the
>> screwdrivers I have that are labeled "Genuine Phillips" do seem to be
>> quite a bit better than the generic variety. One aspect of the
>> Phillips head not shared by Torx or Robertson/square is that it will
>> automatically center the driving bit.
>>
>
> I don't follow on the automatic centering. Yes, a slotted screwdriver can
> slide out, but torx or robertsons?
>
>
>> The "slipping out", I believe is referred to as "camming out".
>>
>> While rebuilding a deck this summer, I found that even square-drive
>> screws are easy to strip when power is used to drive them.
>>
>
> That's why you're supposed to use a drill with a slipper clutch.
>
>
>> Fortunately, deck screws are being manufactured with the Torx head
>> (mine were T25s) and allow for much better driving performance.
>>
>
>
>
>
>From: Tim McNerney <mc at media.mit.edu>
>Subject: RX01 missing felt pad, repair advice
>
>The felt pad that presses the floppy disk into the r/w head fell off my
>RX01 (or whatever dual floppy drive is actually inside a DECmate model
>III (a late edition of 6120-based PDP-8).
>Has anyone tried to do that repair? What did you use for replacement,
>self-adhesive felt material?
>
*I've not worked on a RX-01 before, but I've been keeping my eye out for
suitable felt button replacements. The only thing I've seen so far as
these felt pellets used in pellet guns... they come in .177 - .22 inch
sizes. If you've lost the carrier as well, you've got a slightly
more difficult problem.
JS
*
>Date: Sun, 23 Nov 2008 20:41:26 -0000
>From: "Jim Beacon" <jim at g1jbg.co.uk>
>
>From: <js at cimmeri.com>
>
>>> Are DEC Letterprinter 100's in nice, working, non-noticeably-yellowed
>>> condition worth anything at present? Or are they pretty much recycling
>>> fodder?
>>
>>
>Don't know if they are worth anything, I've never had to pay for one - they
>just keep arriving here!
>
>They are useful though, as they correctly emulate a Teletype and allow
>overprinting, which most modern printers don't, but I suppose that's only
>useful if you have an interest in ASCII art!
>
>Jim.
>
Interesting. Well, my use is just for general programming printouts on
a PDP 11/23+. Is the LA75 a viable replacement for the Letterprinter
100? The 75 isn't period to the 11/23, but my concern about the 100
is ribbons. Ribbons for the LA75 are plentiful and cheap.
Thanks Jim, Tony, Allison for your replies.
JS
I give up - what's a LK207-EE?
http://www.sparetimegizmos.com/Downloads/LK207-EE.JPG
It's clearly a cousin to the LK201; it has the same keys as a LK201 but with
a different physical arrangement. The paper labels stuck on the keycaps
would make me think that it was used in some kind of stock broker
application, but I've never seen or heard of anything like it before.
Bob
As a tangent to the "first" computer on the internet, I reference this
interesting link, showing the IMP log, along with the date and time of
the "birth" of said [I][i]nternet.
See:
http://www.lk.cs.ucla.edu/first_words.html
-eric
-- Jules Richardson <jules.richardson99 at gmail.com> wrote:
>Gordon JC Pearce MM3YEQ wrote:
>> micheladam at theedge.ca wrote:
>>> Does anyone know of a 'bridge' converter that would allow a scsi >disk
>>> to interface to an MFM controller?
>>>
>>> Michel Adam
>>
>> I'm not sure how that would work. Do you mean replacing an >existing MFM
>> disk with a SCSI disk?
>
>It's been talked about at various times on the list here...
>
>It needs high-speed sampling of the MFM data at the track level into >buffer
>memory, and some smarts to translate the buffer memory into blocks on >the drive.
>
>It *could* be done, but nobody's made it work yet AFAIK.
>
>cheers
>
>Jules
Commercial products exist, for example at:
www.mbiusa.com/mbi_000010.htm
But I imagine they're *FRIGHTFULLY* expensive . . . .
____________________________________________________________
Enjoy the type-anywhere ease of a wireless keyboard. Click now!
http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw1aNvZao9Vy0jrsWZZZiMWt9Xz…
I just put up a large collection of documentation on the 1900
hardware over the past couple of days under
http://bitsavers.org/pdf/ict_icl/1900
Has anyone heard anything from Brian Spoor lateley? I'm concerned
since his last post on AFC seems to be from about a year ago.
All:
I?m working on adding support in the Altair32 Emulator for directly
reading WAV file samples of audio cassettes. Initially, I?m working with the
88-ACR but it should be a snap to modify that code to support the KCS.
A WAV sample sent to me by the person who asked me to look into adding
this capability is a cassette from 1977 called the MITS Disk Boot Loader.
I?ve known this to be usually distributed on PROM, but I guess if you didn?t
have a PROM board, the cassette makes sense. I actually have the source and
ROM binary already because I use it for the floppy disk support in the
Altair32.
Anyway, me and a buddy of mine are starting to parse the WAV samples and
it would help greatly if we could get a copy of the manual for the DBL. The
owner of the tape doesn?t have it. What I?m really looking for is the toggle
loader or whatever was used to bring the DBL in from cassette.
If anyone has it and would be willing to scan it for me, I?d appreciate
it. Thanks!
Rich
--
Rich Cini
Collector of Classic Computers
Build Master and lead engineer, Altair32 Emulator
http://www.altair32.comhttp://www.classiccmp.org/cini
Hi,
I was digging through my collection at the weekend and came across this
paper tape reader(?). Can anyone help me identfy it?
I've put some pictures up on my blog here:
http://www.pdp8.co.uk/2008/11/26/mystery-paper-tape-reader/
It is labelled on the front as a ?Paper Tape Comparator?. It has an
optical array for scanning the tape and an adjustable width feeder to
support 3 different sizes. I can't find any indication of its make which
makes me wonder if its scratch built with bits from another device.
On the back is a female 25 pin D socket which I assume to be an RS232
outlet. There is also a 3 pin power socket in a format I don?t
recognise.
Any information would be greatly appreciated.
Thanks,
Toby
--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.
A fascinating topic.
Here's a fun patent to read:
http://www.google.com/patents?id=lBJtAAAAEBAJ
Patent number: 2614169
Filing date: Jul 24, 1950
Issue date: Oct 1952
Inventor: A. A. COHEN
Assignee: Engineering Research Asso
Some mention is made of how they made it in 1950.
Coombs original patent:
http://www.google.com/patents?id=gSBXAAAAEBAJ&dq=patent:3119110
Patent number: 3119110
Filing date: May 2, 1949
Issue date: Jan 21, 1964
Inventor: J. M. COOMBS
Assignee: Sperry Rand Corporation
They appear to use spray paint --- not deposition.
