VCF East update - three keynotes, TWO original Apple 1, etc.

Hi classiccmp'ers. VCF East starts in just 8 days from now. It's at the InfoAge Science Center in Wall, New Jersey, USA. Three keynotes: John Blankenbaker (Friday), Stewart Cheifet (Saturday), Ted Nelson (Sunday). Three dozen hands-on exhibits. TWO original Apple 1 computers, including one

Re: Why do good floppy disks go bad?

On 04/06/2016 06:00 PM, Paul Koning wrote: > I have no experience with this issue in floppies. But I have a > distressingly large quantity of audio cassettes that have gone bad > over 10 or 20 years. It wasn't wear; they weren't played regularly. > Instead, something bad happened with the

RE: AT 4425 (Teletype 56D) repair

> > The "SL0227 / 404780" part appears to be a Zilog Z80 CPU of some kind, The '404780' number looks a bit like a Teletype part number... IIRC the Z80 has very odd positions for the power and ground pins, you should be able to verify that it is a Z80 from that. Then stick a 'scope or counter on

Re: Why do good floppy disks go bad?

On 04/06/2016 10:20 AM, Swift Griggs wrote: When left in an unprotected state, or a poor environment, damp, mold and dust can damage the surface, either degrading the magnetic layer or causing the gap to shrink enough that the drive head physically damages the disk? Gap? There IS no gap on a

Re: Why do good floppy disks go bad?

> On Apr 6, 2016, at 8:55 PM, Geoff Oltmans wrote: > > On a related note... What causes an old mfm / roll drive to die if the heads > aren't touching the surface except in the landing zone? > > I have read that it's not impossible for the "pigment" to lose its coercivity

Re: Why do good floppy disks go bad?

> On Apr 6, 2016, at 5:18 PM, Chuck Guzis wrote: > > Well, I don't know about the consensus, but in my experience, most > floppies go bad from wear and/or breakdown in the binder. I have no experience with this issue in floppies. But I have a distressingly large quantity

Re: Why do good floppy disks go bad?

> On Apr 6, 2016, at 3:15 PM, JP Hindin wrote: > > > I had one of those Japanese Koan moments recently when someone asked me "Why > do floppy disks stop working?" and I realised I... didn't actually know. I > thought I'd throw it to the group and get some

VCF Europe, April 30th - May 1st, Munich + registration for VCF Berlin

Hi list, the 17th edition of VCF Europe[0] is coming soon! It will take place on April 30th and May 1st in Munich, Germany. Please be aware that the information on the English version of the website might be outdated or less detailed than on the German page, but Google Translate will help. Also

RE: RSX-11M trouble

Il giorno mer, 06/04/2016 alle 21.59 +0200, supervinx ha scritto: > Ah, sad and bad news... > Transferred ICP.TSK as usual and checked it with DMP (between simh and > the MicroPDP). > Gave it a try, but got a system crash. > I suspect that the Indirect Command Processor is tightly linked with the

Re: AT 4425 (Teletype 56D) repair

* On Wed, Apr 06, 2016 at 03:11:54PM -0600, Eric Smith wrote: > SL0227 is a house number, and isn't likely to mean anything to anyone. > It might be a Z80, but it could just as easily be a mask-programmed > Z8. This is good information. I did measure a 3.3MHz clock signal

Re: Why do good floppy disks go bad?

Well, I don't know about the consensus, but in my experience, most floppies go bad from wear and/or breakdown in the binder. It's sometimes possible to "renew" a bad disk for use by either AC degaussing or use of a strong DC field, but given the cost of the media, it's scarcely worth the

Re: Why do good floppy disks go bad?

On Wed, 6 Apr 2016, JP Hindin wrote: > - Repeated use slowly wears away the magnetic media layer on the mylar. There is no doubt that there is some friction there. However, I'd be surprised if this was the chief cause. > When left in an unprotected state, or a poor environment, damp, mold and >

Re: RSX-11M trouble

> Another curious thing is this... > Dumping the first block with DMP or a Linux/DOS tools gives different > results. > For example: > DMP > === > B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B12 B13 B14 B15 B16 > Linux/DOS > = > B16 B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 > Byte

Re: AT 4425 (Teletype 56D) repair

SL0227 is a house number, and isn't likely to mean anything to anyone. It might be a Z80, but it could just as easily be a mask-programmed Z8.

RE: KY11-LB prints, and versions

Noel wrote: > > My brain did eventually turn on, and I remembered DEC's habit of putting > prints for included devices in with print sets for computers, and with that in > mind, I managed to locate another set in the -11/34A print set; that one is a > lot clearer. > > Anyway, the version in the

Why do good floppy disks go bad?

I had one of those Japanese Koan moments recently when someone asked me "Why do floppy disks stop working?" and I realised I... didn't actually know. I thought I'd throw it to the group and get some theories/proofs. Let's work on the assumption we're talking about 5.25" and 3.5" disks.

RE: RSX-11M trouble

Ah, sad and bad news... Transferred ICP.TSK as usual and checked it with DMP (between simh and the MicroPDP). Gave it a try, but got a system crash. I suspect that the Indirect Command Processor is tightly linked with the kernel... Another curious thing is this... Dumping the first block with

Re: What do members do for substitute monochrome monitors ?

On Mon, Apr 4, 2016 at 7:07 AM, Maciej W. Rozycki wrote: > On Sun, 3 Apr 2016, Pete Lancashire wrote: > > > I'll soon be powering up a HP 9000/310 (98561-66525) but do not have an > a > > single monochrome monitor. > > > > Suggestions ? > > I've had success with a NEC

Re: [HECnet] Document treasure trove

On 2016-04-06 20:26, paul_kon...@dell.com wrote: While looking for DECnet documents, I noticed that there's a very large collection at http://manx.classiccmp.org/collections/antonio/dec/ . Probably not news to many, but in case some had not seen it... Among other things, there are two CD

Document treasure trove

While looking for DECnet documents, I noticed that there's a very large collection at http://manx.classiccmp.org/collections/antonio/dec/ . Probably not news to many, but in case some had not seen it... Among other things, there are two CD collections MDS-1997-10 and MDS-2000-01. The former

MEM11A Status

Hi, The board layout is complete and has passed all of the design rule checks from the board house. I’ll be ordering some boards for me to assemble and test next week. I have also received a quote for “turnkey assembly” where I hand them the files and get back fully assembled boards. In order

Re: AT 4425 (Teletype 56D) repair

One more quick question about this. Here's a close-up of the CPU and IO support chips on the terminal main board: http://i.imgur.com/6ZXwcLm.jpg The "SL0227 / 404780" part appears to be a Zilog Z80 CPU of some kind, but I've never seen those markings. The MOSTEK parts are Z80 SIO and Z80

Re: A computer collection in Italy

On 06/04/16 15:38, Dave Wade wrote: I wish I had such an inventory of my collection I wish I had a 4000sqm building nearby :-) I'm much more likely to (eventually) build up an inventory of the stuff I do have (that's just time and effort ...). Antonio -- Antonio Carlini

Front Panels Latest

Hi Guys PDP-8/e A panels now shipping PDP 8/e B panels ship on Friday PDP-8/ f and /m ship on 14th I have some extras of the above if you are quick. Rod (Panelman) Smallwood

RE: A computer collection in Italy

I wish I had such an inventory of my collection > -Original Message- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Pontus > Sent: 06 April 2016 11:32 > To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off- > Topic Posts >

Re: KY11-LB prints, and versions

On Wed, 6 Apr 2016 09:08:55 -0400 (EDT) j...@mercury.lcs.mit.edu (Noel Chiappa) wrote: --snip-- > Anyway, the version in the -11/34A prints didn't include the actual > front console, plus to which the prints there had been heavily marked > up by someone at some point. So I have produced a new

KY11-LB prints, and versions

So I'm in the process of repairing a couple of M7859 KY11-LB -11/04-34 Programmer's Console boards, and the existing FM Print Set was kind of hard to read in some areas, so I looked online for another set, and although I didn't find one, I noticed several other people with the same issue - asking

RSX-11M trouble

>> The closest RSX11M (not Plus) distribution I can find is an RL01 >> distribution of RSX11M V4.1 >> Since it is disk and not tape it can be directly booted with Simh and it >> does have a ICP.TSK >> that should be pretty compatible with V4.2 since it is from V4.1 Baseline. >> You can

Re: A computer collection in Italy

On 04/05/2016 04:31 PM, Christian Corti wrote: On Tue, 5 Apr 2016, Pontus Pihlgren wrote: http://www.retrocomputing.net/ Looks like he has both an 11/780 (though it looks to be in pieces) and a 390. Impressive collection. ... that get's much smaller if you omit all those entries for flat

Re: 3B2 C compiler and Assembler

Hi. I am searching for a long time a similar set of 5.25 diskettes for my 3B1. If someone could provide me a copy it would be great. Kind Regards Sergio 2016-04-06 6:45 GMT+02:00 Jerry Kemp : > Thank you again for all the updates, and all the work you have done on the > 3B2