- test-drb@ccmp.vtda.org - classiccmp.org

by michael.99.thompson＠gmail.com

DECtapes have 5x redundant tracks. If you could find an 8-track head that had the same track pitch, and maybe track width, you could read the tape but lose redundancy on the Mark and Timing tracks. That probably would not work with a marginal DECtape. On Mon, Feb 7, 2022 at 3:33 PM Wayne S <wayne.sudol at hotmail.com> wrote: > I?ve often wondered if the tape heads from consumer tape devices such as > cassette or 4-8 track tape players could be used or be made to be used as > replacements. Anybody ever try that? > > Sent from my iPhone > > > On Feb 7, 2022, at 11:51, Michael Thompson via cctech < > cctech at classiccmp.org> wrote: > > > > ? > >> > >> > >> From: Gary Oliver <go at aerodesic.com> > >> Subject: DECTape head problem > >> > >> In debugging my DECtape interface lashup, I found that one of my head > >> has two open windings.? Specifically, one channel has an open 'ground' > >> with the other two lines apparently the full winding of the channel.? > >> The second channel failing has no continuity between any of the three > >> lines.? I have tested the other head and it has all the requisite > >> continuity so I'm hoping I can at least get a single spindle running. > >> > >> Has any ever attempted repair of one of these? > >> > >> -Gary > >> > > > > At the Rhode Island Computer Museum we found several DECtape heads on > TU55 > > and TU56 drives with open connections. A volunteer got one head X-Rayed > so > > we could see the solder joints between the tiny wires for the head coils, > > and the larger twinax wires that go to the relay board. We couldn't see > any > > damage to the wires or solder joints. > > > > We tried heating the potting material to soften it, and digging it out to > > get to the solder joints. While digging at the potting material you can't > > see the tiny wires, so they will likely get damaged. > > > > We considered using a solvent to remove the potting material, but thought > > that it would eat the enamel off the head coil wires and damage them > beyond > > repair. > > > > So far we haven't found a way to repair the heads. > > > > Michael Thompson > -- Michael Thompson

4 years, 1 month

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DECTape head problem

by michael.99.thompson＠gmail.com

> > From: Gary Oliver <go at aerodesic.com> > Subject: DECTape head problem > > In debugging my DECtape interface lashup, I found that one of my head > has two open windings.? Specifically, one channel has an open 'ground' > with the other two lines apparently the full winding of the channel.? > The second channel failing has no continuity between any of the three > lines.? I have tested the other head and it has all the requisite > continuity so I'm hoping I can at least get a single spindle running. > > Has any ever attempted repair of one of these? > > -Gary > At the Rhode Island Computer Museum we found several DECtape heads on TU55 and TU56 drives with open connections. A volunteer got one head X-Rayed so we could see the solder joints between the tiny wires for the head coils, and the larger twinax wires that go to the relay board. We couldn't see any damage to the wires or solder joints. We tried heating the potting material to soften it, and digging it out to get to the solder joints. While digging at the potting material you can't see the tiny wires, so they will likely get damaged. We considered using a solvent to remove the potting material, but thought that it would eat the enamel off the head coil wires and damage them beyond repair. So far we haven't found a way to repair the heads. Michael Thompson

4 years, 1 month

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KW11-L ON eBait

by jnc＠mercury.lcs.mit.edu

https://www.ebay.com/itm/393915648077 I've already got one for my machines that take one! Noel

4 years, 1 month

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Odd jumpers on a XT 2190 drive.

by g-wright＠att.net

I'm going through? a few of my ESDI? and MFM hard drives? and ran across?2 Maxtor? XT 2190 drives with? all of the Drive Id's (1-4) tie together with 1 long jumper and the drives have the write protect jumper is installed.? Not sure what theywould have been used for ??? Both are the same. Jerry

4 years, 1 month

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IBM 129 keypunch on Ebay

by ccth6600＠gmail.com

There is a nice looking IBM 129 keypunch on Ebay for what I think is a very reasonable "buy it now" price of US$1799: https://www.ebay.com/itm/333898748391 Shipping to Australia would be horrendous otherwise I would have bought it. Best regards Tom Hunter

4 years, 1 month

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Odd board in a pdp8/e

by cz＠alembic.crystel.com

I'm putting stuff together here and it's time to begin working on the 8/E. Looks like a pretty generic system but it has two odd boards. Pair of g227 memory boards, 4 board CPU+Console board, serial board, nothing too special. But two odd Omnibus cards: One is a memory board, half populated, my guess is it's enough memory to bring the computer to 32kw. The other is an mets 303-0115-001. Bunch of 7400 series logic chips, nothing too special. Any idea what it might have been? Timeshare option? Something else? Not a peripheral controller from what I can see. C

4 years, 1 month

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cctalk Digest, Vol 89, Issue 3

by bobsmithofd＠gmail.com

On Thu, Feb 3, 2022 at 1:08 PM <cctalk-request at classiccmp.org> wrote: > > Send cctalk mailing list submissions to > cctalk at classiccmp.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.classiccmp.org/mailman/listinfo/cctalk > or, via email, send a message with subject or body 'help' to > cctalk-request at classiccmp.org > > You can reach the person managing the list at > cctalk-owner at classiccmp.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of cctalk digest..." > > > Today's Topics: > > 1. (John Ames) > 2. Re: (Paul Koning) > 3. Re: (Jon Elson) > 4. Re: KMC11/DMC11 folllow up (Dave Mitton) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 2 Feb 2022 10:20:25 -0800 > From: John Ames <commodorejohn at gmail.com> > To: cclist at sydex.com > Cc: cctalk at classiccmp.org > Message-ID: > <CABCBCvP8SX_1rB3FXVxZuXx1SUFTfiJBTqePd_SZiNeReX7PEw at mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > > Back in the bad old days of the 5160 PC, some DTC controllers allowed for partitioning a drive (using witch settings) > I think "witch settings" is my new preferred term for this. They're > certainly mysterious and arcane enough. > > > ------------------------------ > > Message: 2 > Date: Wed, 2 Feb 2022 13:30:33 -0500 > From: Paul Koning <paulkoning at comcast.net> > To: John Ames <commodorejohn at gmail.com>, "cctalk at classiccmp.org" > <cctalk at classiccmp.org> > Subject: Re: > Message-ID: <B8F20F9C-A329-4CED-9A00-036EAA8F4D1A at comcast.net> > Content-Type: text/plain; charset=us-ascii > > > > > On Feb 2, 2022, at 1:20 PM, John Ames via cctalk <cctalk at classiccmp.org> wrote: > > > >> Back in the bad old days of the 5160 PC, some DTC controllers allowed for partitioning a drive (using witch settings) > > I think "witch settings" is my new preferred term for this. They're > > certainly mysterious and arcane enough. > > Nice. It would be a good term to apply to VMS SYSGEN parameters that are documented as having units "microfortnights". > > paul > > > > ------------------------------ > > Message: 3 > Date: Wed, 2 Feb 2022 16:49:42 -0600 > From: Jon Elson <elson at pico-systems.com> > To: Paul Koning via cctalk <cctalk at classiccmp.org> > Subject: Re: > Message-ID: <b0989916-7493-481d-7c45-a696ce5ecc31 at pico-systems.com> > Content-Type: text/plain; charset=UTF-8; format=flowed > > On 2/2/22 12:30, Paul Koning via cctalk wrote: > > > >> > > Nice. It would be a good term to apply to VMS SYSGEN parameters that are documented as having units "microfortnights". > > > A footnote in the system config guide noted that ufortnights > would be approximated at one second. > > Jon > > > > ------------------------------ > > Message: 4 > Date: Wed, 2 Feb 2022 14:31:27 -0500 > From: Dave Mitton <dave at mitton.com> > To: "cctech at classiccmp.org" <cctech at classiccmp.org> > Subject: Re: KMC11/DMC11 folllow up > Message-ID: <20220202193130.24EDC4E775 at mx2.ezwind.net> > Content-Type: text/plain; charset="utf-8" > > Date: Tue, 1 Feb 2022 18:46:46 -0500 > From: Bob Smith <bobsmithofd at gmail.com> > Subject: Re: KMC11/DMC11 folllow up > Message-ID: > I?ve been watching this thread go by, and never finding time to contribute?. > > I started in Aug 1977 and finished the CommIOP products from Bob and Harvey. Clarise was no longer involved. > It was basically done, I just did the QA on them and released it. I did find some bugs in the debugger we provided. > > I basically did KMC software support, on and off, going forward. When the KMC-B came out (I think Remi did that) > I rev?ed the tools. I also did a KMC Tools package for VMS. I tossed into that package a VMS line printer driver, I wrote as an example and POC, that ran multiples LP11s at significantly better speed. We ran that in our lab. The MIT LCS lab loved that. > > My memory is weak on things like the ?DMX? and other things that CSS did. The Lab Products group built some successful data collection products around the KMC. > > Attempts in the Comms HW group to do an updated UNIBUS DH never got off the ground. We (NAC) did pitch the idea of using the CommIOP-DZ to VMS, as a way to off-load character terminal loads, and they would have nothing to do with it. For whatever reasons, they did not like the idea of smart devices. > > That led to the attempt to build a ?universal? terminal concentrator based on an 11 networked into the system. That project was complicated by what it tried to integrate, and took too long to build. It was overtaken by the simpler LAT based products that DEC went forward with. > > George Conant, Bob Rosenbaum, and Pete Nesbeda left the company and founded Xyplex that fielded successful products in this space. > > I could go on, but ? I do have copies of the KMC Tools doc and maybe the CommIOPs, but no KMC hw docs. > Dave. > > Sent from Mail for Windows > > Hey Dave! I did not mention you because I was not sure you wanted to recall those days! you are correct it was Remi Lisee doing the design, I did the first line units, and then they were redone a few years later. Glad you piped in!! Hope you are doing great! All of you guys were brilliant, except Harvey, he was a royal pain, said with lots of laughs we both got tired or burning roms!! bob smith

4 years, 1 month

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No subject

by commodorejohn＠gmail.com

> Back in the bad old days of the 5160 PC, some DTC controllers allowed for partitioning a drive (using witch settings) I think "witch settings" is my new preferred term for this. They're certainly mysterious and arcane enough.

4 years, 1 month

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KMC11/DMC11 folllow up

by dave＠mitton.com

Date: Tue, 1 Feb 2022 18:46:46 -0500 From: Bob Smith <bobsmithofd at gmail.com> Subject: Re: KMC11/DMC11 folllow up Message-ID: <CAHtNYbXBRwrOQm2cH+T+CDn5nq3sZN+PQRa9fEMVhqQ=pAMDSw at mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Yes! thank you! Nice, smart, and did good work despite the magateer, I mean marketing dweeb. I lost track of Harvey, Bob wen ont to start a company over in west concord, can't recall the name, used some of his gear for projects in the mid 80s. I was designing a comms system in late 80s and heard Len Bosak had started a company, had a couple of meetings with him, and went with hs gear. Man those were fun post DEC projexcts. bob smith (PDP8 engineering, DecComm (Stockebrand, VInce et al), small systems, then of toe LCG for 2080... On Tue, Feb 1, 2022 at 2:43 PM John Forecast <john at forecast.name> wrote: > > On Feb 1, 2022, at 8:20 AM, Bob Smith via cctalk <cctalk at classiccmp.org> wrote: > > > > KMC11 - Paul K cited the docs. It was a bit different from DMC CPU board > > in both cycle time and in the use of ram versus prom. > > Both boards/products used the 4bit Alu but I don't call that bit > > slice, as the 2901 is more of a bit slice. > > KMC and DMC are Harvard architecture based devices, as is the 11/60 CPU. > > DMC and KMC benefited from the microcode work of Harvey Schlesinger, > > Bob Rosenbaum, Richie Larry, and I think Clarise joined the team in > > 77. Can't recall her last name. > > Patton? Harvey, Bob and Clarise joined the DECnet-RSX development team sometime in 77/78. > > John. > > > DMC had (when I left the project and it had been shipping for a year > > or two) a 300NS cycle time, while the KMC had a 240NS cycle time > > thanks to the instruction register I had suggested to remi as we were > > thinking of a RAM based device because PROMS were a royal pain with 2 > > and 3 code changes a day. This change allowed the machine to begin to > > access the next instruction as one was executing - there are no > > interrupts in either board. > > bob > I?ve been watching this thread go by, and never finding time to contribute?. I started in Aug 1977 and finished the CommIOP products from Bob and Harvey. Clarise was no longer involved. It was basically done, I just did the QA on them and released it. I did find some bugs in the debugger we provided. I basically did KMC software support, on and off, going forward. When the KMC-B came out (I think Remi did that) I rev?ed the tools. I also did a KMC Tools package for VMS. I tossed into that package a VMS line printer driver, I wrote as an example and POC, that ran multiples LP11s at significantly better speed. We ran that in our lab. The MIT LCS lab loved that. My memory is weak on things like the ?DMX? and other things that CSS did. The Lab Products group built some successful data collection products around the KMC. Attempts in the Comms HW group to do an updated UNIBUS DH never got off the ground. We (NAC) did pitch the idea of using the CommIOP-DZ to VMS, as a way to off-load character terminal loads, and they would have nothing to do with it. For whatever reasons, they did not like the idea of smart devices. That led to the attempt to build a ?universal? terminal concentrator based on an 11 networked into the system. That project was complicated by what it tried to integrate, and took too long to build. It was overtaken by the simpler LAT based products that DEC went forward with. George Conant, Bob Rosenbaum, and Pete Nesbeda left the company and founded Xyplex that fielded successful products in this space. I could go on, but ? I do have copies of the KMC Tools doc and maybe the CommIOPs, but no KMC hw docs. Dave. Sent from Mail for Windows

4 years, 1 month

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Origin of "partition" in storage devices

by tom94022＠comcast.net

There is a discussion of the origin of the term "partition" in storage devices such as HDDs at: https://en.wikipedia.org/wiki/Talk:Disk_partitioning#Where_did_the_term_%22p artition%22_originate? It seems clear it was used in memory well before HDDs but when it got started there is unclear. * IBM PC DOS v2 was an early user in 1983 with FDISK and its first PC support of HDDs * UNIX, Apple OS's and IBM mainframe all seem to come later. Partitioning as a "slice" probably predates IBM PC DOS v2 Would appreciate some recollections about DEC usage, other minicomputers and the BUNCH. You can either post directly to Wikipedia or let me know; links to references would greatly be appreciated Tom

4 years, 1 month

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Origin of "partition" in storage devices

by jnc＠mercury.lcs.mit.edu

> From: Tom Gardner > You define logical disks by assigning a logical disk unit number to a > file on a physical disk. You can then use the logical disk as though it > were a physical disk. To me, 'partition' implies a contiguous are of the disk; "a file" to me implies that it might not be contiguous? Or are files contiguous in the RT-11 filesystem? (I know there were filesystems which supported contiguous files.) This reminds me of the swapping/paging area in Windows 95/98 (maybe other versions too), which was kept in a file, and therefore might be scattered all over the physical disk. (Norton disk optimizer would coalesce the swap/paging area to a contiguous area of the disk.) Noel

4 years, 1 month

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KMC11/DMC11 folllow up

by bobsmithofd＠gmail.com

KMC11 - Paul K cited the docs. It was a bit different from DMC CPU board in both cycle time and in the use of ram versus prom. Both boards/products used the 4bit Alu but I don't call that bit slice, as the 2901 is more of a bit slice. KMC and DMC are Harvard architecture based devices, as is the 11/60 CPU. DMC and KMC benefited from the microcode work of Harvey Schlesinger, Bob Rosenbaum, Richie Larry, and I think Clarise joined the team in 77. Can't recall her last name. DMC had (when I left the project and it had been shipping for a year or two) a 300NS cycle time, while the KMC had a 240NS cycle time thanks to the instruction register I had suggested to remi as we were thinking of a RAM based device because PROMS were a royal pain with 2 and 3 code changes a day. This change allowed the machine to begin to access the next instruction as one was executing - there are no interrupts in either board. bob

4 years, 1 month

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Origin of "partition" in storage devices

by jnc＠mercury.lcs.mit.edu

> From: Paul Koning > When did Unix first get partitions? 'Partitions' the mechanism, or partitions the term for the mechanism? The former appeared about V5: https://minnie.tuhs.org/cgi-bin/utree.pl?file=V5/usr/sys/dmr/rp.c when an RP03 was added; pre-V7, UNIX filesystems were limited to 2^16 blocks, so the 406*10*20 blocks of an RP03 had to be split up into partitions (called 'sections' or 'pseudo-disks' in the documentation) to make all of it useable. The latter? No idea... Partitions may have appeared in DOS/Windows for much the same reason; with 32 KB clusters, FAT16 filesystems were limited to 2GB. I distinctly recall having to use partitions when I bought a 13GB hard drive for my Windows 95 machine (FAT32 only came in with Windows 95 OSR2). Noel

4 years, 1 month

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Origin of "partition" in storage devices

by tom94022＠comcast.net

A somewhat broader search found the 1984 RT-11 System Release Notes with the following: 1.4.2.4 Logical Disk Subsetting Handler (LD) - The logical disk subsetting handler lets you define logical disks, which are subsets of physical disks. You define logical disks by assigning a logical disk unit number to a file on a physical disk. You can then use the logical disk as though it were a physical disk. AA-5286F-TC-T1_RT-11_System_Release_Notes_Jul84.pdf (bitsavers.org) <http://www.bitsavers.org/pdf/dec/pdp11/rt11/v5.1_Jul84/AA-5286F-TC-T1_RT-11…> p15/102 Suggests DEC had not yet adopted the term ?partition? for a segment of a disk Tom -----Original Message----- From: Tom Gardner [mailto:tom94022 at comcast.net] FWIW a Google search: "partition site:http://www.bitsavers.org/pdf/dec/pdp11/rt11" returns no relevant hits prior to 1983 I suspect that ESDI and MFM controllers emulating RL/RK disks are also later than 1983 Tom -----Original Message----- From: Zane Healy [ <mailto:healyzh at avanthar.com> mailto:healyzh at avanthar.com] Sent: Monday, January 31, 2022 12:40 PM To: Paul Koning; General Discussion: On-Topic and Off-Topic Posts Cc: <mailto:t.gardner at computer.org> t.gardner at computer.org; Tom Gardner Subject: Re: Origin of "partition" in storage devices On Jan 31, 2022, at 11:28 AM, Paul Koning via cctalk < <mailto:cctalk at classiccmp.org> cctalk at classiccmp.org> wrote: > > Both of these are memory partitions. The only OS I can think of predating the ones you mentioned is RT-11, the later versions (V2 did not have them). When did Unix first get partitions? > > paul Partitions are pretty important in RT-11 v5.x, after all, there is the partition size limit, so you have to have multiple partitions for almost any HD, except very small ones. Let?s not forget hardware enforced partitioning, the WEQSD/04 ESDI controller comes to mind. It see?s a single large ESDI HD as a single disk, but you can partition it on the controller, and the OS sees each partition as a separate physical disk. I seem to remember some MFM controllers that made the MFM drive appear to be RL01/RL02 or RK05 packs. Zane

4 years, 1 month

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Pdp 8 panel parts for trade

by tdk.knight＠gmail.com

Anyone got any 8i switch or panel parts they Wana trade for any of these? Got 6 3 pin spring loaded rockers appear to test good might need some deoxot not sure came off the 8e below 8 of the 8e m rocker paddles orange and redish orange https://drive.google.com/file/d/1Eprlv8d3TmSPFJ3rCHIJTFkQOyAZesCM/view?usp=… Some are missing the plastic pivot dimples 8m with out it's switches The rotory it's bit weird but possibly usable. Dunno enough about them. It's center hole is ovaled a bit might gotten bashed. Might have some usefull bits still https://drive.google.com/drive/folders/1EpAag1J5r6RAR8ln_fprrdCEiOnJx5kq I've got some other bits that might be usefull as well from the 8i to anyone I'm looking for 5 more rockers with or with out the 8i paddles Or some 8i paddles I've got 5 brown and 10 white ones that I wanted to find when I rescued my poor 8i outs the mud Or any other parts that might be usefull

4 years, 1 month

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What was a Terminal Concentration Device in DEC's products?

by jnc＠mercury.lcs.mit.edu

> From: Bob Smith > the original UART was designed by DEC, Vince Bastiani was the project > lead and designer, Gordon Bell was behind the project, and it may have > been his idea. "Computer Engineering: A DEC View of Hardware Systems Design" covers this, in a footnote on pg. 73. I seem to recall reading that Ken Olsen was involved in doing early modem work (presumably on Whirlwind), but maybe my memory is failing, and it was someone else (like Bell, or someone). Too busy to research it at the moment... Noel

4 years, 2 months

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MG10 parts

by useddec＠gmail.com

While moving some things around I found the following: 7 M8588 6 M8591 6 M8592 4 M8593 14 M8594 All appear to be NOS. I also found : G103 G222 G223 M911 Which I did not count, and they seem to be memory related, but I haven't checked to see which memory they are from. If you have any interest please contact me off list. Thanks, Paul

4 years, 2 months

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What was a Terminal Concentration Device in DEC's products?

by jnc＠mercury.lcs.mit.edu

> From: Chris Zach > Maybe that is the dhv11. The DH11, DHV11 and DHU11 are all very similar, although not 100.00% program compatible. (The DHQ11 can be set to exactly emulate either the DHV11 or DHU11.) So, all provide DMA output, but not DMA input. Differences with the DH11 include two full word registers for DMA address, hardware ^S/^Q support, built-in diagnostics, etc. The DHV11 and DHU11 differ in hardware echo, output FIFO, a fix for the infamous DH11 input silo level bug, etc. Noel

4 years, 2 months

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ISO: Canon Scanner Driver

by silent700＠gmail.com

In order to further the effort of scanning and preserving ALL of the things, I picked up a Canon Microfilm Scanner 300 for $cheap. It has a SCSI interface and doesn't work with anything past Windows XP, but that's not a problem. What is a problem is that Canon's link to the XP driver is a big 4 0 4: https://www.usa.canon.com/internet/portal/us/home/support/details/scanners/… By any chance, does someone out there have this driver? The filename in question is "300350DRIT_V11.exe". You can google that name and end up either back at Canon's site or in Malware Hell ("just download this Chrome plugin to get your driver!"). Note that this is not the Canon Microfilm Scanner 300-II, which is a USB device and uses a different driver. Thanks for any leads... jt

4 years, 2 months

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cctalk Digest, Vol 88, Issue 30

by bobsmithofd＠gmail.com

IIRC, John Mac was the designer for the DHQ/DHV. If my memory is correct, after DH was done, John had the idea of a mix and match synchronous/Async mux and came up with those designs. I dont remember who was on his team. COMMS 11 group had led (farmed out) the designs of the Sync version of a UART called USynRT in some parlance SIg 2652 and SMC 5027 IIFC. I ran the Signetics contract tech side. A fresh MIT PhD was the Sig POC, and there are more stories about that. I cant recall his name at this juncture. bob On Sun, Jan 30, 2022 at 1:00 PM <cctalk-request at classiccmp.org> wrote: > > Send cctalk mailing list submissions to > cctalk at classiccmp.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.classiccmp.org/mailman/listinfo/cctalk > or, via email, send a message with subject or body 'help' to > cctalk-request at classiccmp.org > > You can reach the person managing the list at > cctalk-owner at classiccmp.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of cctalk digest..." > > > Today's Topics: > > 1. Re: What was a Terminal Concentration Device in DEC's > products? (Noel Chiappa) > 2. Re: What was a Terminal Concentration Device in DEC's > products? (Paul Koning) > 3. Re: What was a Terminal Concentration Device in DEC's > products? (Chris Zach) > 4. Re: What was a Terminal Concentration Device in DEC's > products? (Glen Slick) > 5. Re: What was a Terminal Concentration Device in DEC's > products? (Noel Chiappa) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 29 Jan 2022 15:58:53 -0500 (EST) > From: jnc at mercury.lcs.mit.edu (Noel Chiappa) > To: cctalk at classiccmp.org > Cc: jnc at mercury.lcs.mit.edu > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <20220129205853.15EEA18C07B at mercury.lcs.mit.edu> > > > From: Paul Koning > > > DH-11 is unusual in that it has DMA in both directions > > McNamara's DH11? (I don't know of another DECdevice of that name.) Per: > > http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… > > it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. > > Noel > > PS: I am familiar with the term 'terminal concentrator' from the networking > world, but as a generic term, not the name of a particular product. (Although > Cisco's first boxes may have included a terminal concentrator, so named.) > > Noel > > > > ------------------------------ > > Message: 2 > Date: Sat, 29 Jan 2022 17:12:41 -0500 > From: Paul Koning <paulkoning at comcast.net> > To: Noel Chiappa <jnc at mercury.lcs.mit.edu>, "cctalk at classiccmp.org" > <cctalk at classiccmp.org> > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <684F1FCF-A6E6-4F3C-AC39-ADA1504FC9E1 at comcast.net> > Content-Type: text/plain; charset=us-ascii > > > > > On Jan 29, 2022, at 3:58 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote: > > > >> From: Paul Koning > > > >> DH-11 is unusual in that it has DMA in both directions > > > > McNamara's DH11? (I don't know of another DECdevice of that name.) Per: > > > > http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… > > > > it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. > > Oh. That's amazing, all these years I thought it had DMA both ways. Clearly not. I wonder how I got that misunderstanding. > > paul > > > > ------------------------------ > > Message: 3 > Date: Sat, 29 Jan 2022 18:49:06 -0500 > From: Chris Zach <cz at alembic.crystel.com> > To: Paul Koning <paulkoning at comcast.net>, "General Discussion: > On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>, Paul Koning via > cctalk <cctalk at classiccmp.org>, Noel Chiappa > <jnc at mercury.lcs.mit.edu>, "cctalk at classiccmp.org" > <cctalk at classiccmp.org> > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <24F062E4-8B26-4EB3-A573-B47C69A53B67 at alembic.crystel.com> > Content-Type: text/plain; charset=utf-8 > > Maybe that is the dhv11. Or the dv11 I'll look it up tomorrow > > On January 29, 2022 5:12:41 PM EST, Paul Koning via cctalk <cctalk at classiccmp.org> wrote: > > > > > >> On Jan 29, 2022, at 3:58 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote: > >> > >>> From: Paul Koning > >> > >>> DH-11 is unusual in that it has DMA in both directions > >> > >> McNamara's DH11? (I don't know of another DECdevice of that name.) Per: > >> > >> http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… > >> > >> it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. > > > >Oh. That's amazing, all these years I thought it had DMA both ways. Clearly not. I wonder how I got that misunderstanding. > > > > paul > > > > -- > Sent from my Android device with K-9 Mail. Please excuse my brevity. > > ------------------------------ > > Message: 4 > Date: Sat, 29 Jan 2022 16:47:27 -0800 > From: Glen Slick <glen.slick at gmail.com> > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: > <CAM2UOwL2hi2Crm7ovphGd+UZFPePV+vUzoduan7a2a5Xo+eimw at mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > http://www.bitsavers.org/pdf/dec/qbus/EK-DHQ11-UG-002.pdf > DHQ11 User Guide, EK-DHQ11-UG.002 > > The main application of the M3107 DHQ11 is for interactive terminal > handling; it can also be used for data concentration and real-time > processing. It has two programming modes, DHV11 and DHU11. The > register sets in these modes are compatible with those of the DHV11 > and DHU11 respectively. The preferred mode of operation is DHU11 mode. > The main features of the DHQ11 are: > > ? For transmission: DMA transfers; or for each line, program transfers > to a 1 character transmit buffer in DHV11 mode, or to a 64-character > transmit FIFO in DHU11 mode > > ? For receive: a 256-entry FIFO buffer for received characters, > dataset status changes, and diagnostic information > > The M3118 CXA16 and the M3119 CXA08 have the same programming > interface as the M3107 DHQ11 > > > The M3108 DSV11 can do DMA transfers in both directions, although it > is a synchronous interface, not asynchronous. > > http://www.bitsavers.org/pdf/dec/qbus/EK-DSV11-TM-001_Jan87.pdf > DSV11 Technical Manual, EK-DSV11-TM-001 > > Functional Description (Section 1.5). The DSV11 supports a range of > synchronous protocols on the serial interface, and transfers data to > and from the host by DMA transfer. This section describes the way in > which the DSV11 handles data. > > On Sat, Jan 29, 2022 at 3:49 PM Chris Zach via cctalk > <cctalk at classiccmp.org> wrote: > > > > Maybe that is the dhv11. Or the dv11 I'll look it up tomorrow > > > > On January 29, 2022 5:12:41 PM EST, Paul Koning via cctalk <cctalk at classiccmp.org> wrote: > > > > > > > > >> On Jan 29, 2022, at 3:58 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote: > > >> > > >>> From: Paul Koning > > >> > > >>> DH-11 is unusual in that it has DMA in both directions > > >> > > >> McNamara's DH11? (I don't know of another DECdevice of that name.) Per: > > >> > > >> http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… > > >> > > >> it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. > > > > > >Oh. That's amazing, all these years I thought it had DMA both ways. Clearly not. I wonder how I got that misunderstanding. > > > > > > paul > > > ------------------------------ > > Message: 5 > Date: Sun, 30 Jan 2022 09:26:46 -0500 (EST) > From: jnc at mercury.lcs.mit.edu (Noel Chiappa) > To: cctalk at classiccmp.org > Cc: jnc at mercury.lcs.mit.edu > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <20220130142646.5614818C074 at mercury.lcs.mit.edu> > > > From: Chris Zach > > > Maybe that is the dhv11. > > The DH11, DHV11 and DHU11 are all very similar, although not 100.00% program compatible. > (The DHQ11 can be set to exactly emulate either the DHV11 or DHU11.) So, all provide > DMA output, but not DMA input. > > Differences with the DH11 include two full word registers for DMA address, > hardware ^S/^Q support, built-in diagnostics, etc. The DHV11 and DHU11 differ > in hardware echo, output FIFO, a fix for the infamous DH11 input silo level > bug, etc. > > Noel > > > End of cctalk Digest, Vol 88, Issue 30 > **************************************

4 years, 2 months

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cctalk Digest, Vol 88, Issue 29

by bobsmithofd＠gmail.com

Back in 75-77 time frame, the KMC11 was packaged with DD11 backplane, a controller interface board or an SLU to implement version 2 of the DoD AUTODIN II. Philco Ford element then called Aeronuetronic Ford out ot Cali was the prime. DEC won the hardware portion bidding PDP11 systems using the KMC11 and SLUs ranging from Mode1 to Mode VI. I did the SLUs for Mode VI (ADCCP/SDLC et al) and Mode II (BiSync) out of the Comms 11 group. CSS Nashua did the Async system with I think 64 lines, or more, and labeled it DMX IIRC - my memory could be bad on the name.The COMM IOP concept was another alternative using the DZ/DU boards. Barney Loiter, if he is still around can probably remember who in CSS did the product. I think Frank Zareski, who had moved from Comms group to Semiconductor was involved with or the lead for the DUAL UART chips DEC invented (point for the record, the original UART was designed by DEC, Vince Bastiani was the project lead and designer, Gordon Bell was behind the project, and it may have been his idea.) On Sat, Jan 29, 2022 at 1:00 PM <cctalk-request at classiccmp.org> wrote: > > Send cctalk mailing list submissions to > cctalk at classiccmp.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.classiccmp.org/mailman/listinfo/cctalk > or, via email, send a message with subject or body 'help' to > cctalk-request at classiccmp.org > > You can reach the person managing the list at > cctalk-owner at classiccmp.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of cctalk digest..." > > > Today's Topics: > > 1. Re: simulation of an entire IBM S/360 Model 50 mainframe > (Curious Marc) > 2. What was a Terminal Concentration Device in DEC's products? > (Chris Zach) > 3. Re: What was a Terminal Concentration Device in DEC's > products? (Paul Koning) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 28 Jan 2022 20:53:22 -0800 > From: Curious Marc <curiousmarc3 at gmail.com> > To: Liam Proven <lproven at gmail.com>, "General Discussion: On-Topic and > Off-Topic Posts" <cctalk at classiccmp.org> > Subject: Re: simulation of an entire IBM S/360 Model 50 mainframe > Message-ID: <E6C6C3FB-E0A0-4472-A485-3EA9E1102CEC at gmail.com> > Content-Type: text/plain; charset=utf-8 > > Ah, it was you Liam. Ken is enamored with the new title you bestowed on him. He will now be officially called: Master Ken, Hardware Boffin. > :-) > Marc > > > On Jan 27, 2022, at 11:54 AM, Liam Proven via cctalk <cctalk at classiccmp.org> wrote: > > > > ?On Thu, 27 Jan 2022 at 17:20, Guy N. via cctalk <cctalk at classiccmp.org> wrote: > >> > >> This might be old news to a lot of people here, but I noticed a fun > >> article on The Register today: > > > > Oh cool. Thanks for the link -- that's one of my stories. Glad to hear > > people enjoyed it. :-) > > > > -- > > Liam Proven ~ Profile: https://about.me/liamproven > > Email: lproven at cix.co.uk ~ gMail/gTalk/FB: lproven at gmail.com > > Twitter/LinkedIn: lproven ~ Skype: liamproven > > UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053 > > > ------------------------------ > > Message: 2 > Date: Sat, 29 Jan 2022 00:28:30 -0500 > From: Chris Zach <cz at alembic.crystel.com> > To: CCTalk mailing list <cctalk at classiccmp.org> > Subject: What was a Terminal Concentration Device in DEC's products? > Message-ID: <ba6ec80e-e099-4015-9d58-f33fb4e51c02 at alembic.crystel.com> > Content-Type: text/plain; charset=UTF-8; format=flowed > > Old question: I'm looking through some old reports from 1977 about a > failed DEC project with the DMX11 multiplexer system and there is > reference to the following key items: > > 1) The DMX was designed to handle block mode devices. Fine. > 2) Character mode devices like the VT52's were supposed to use a "TCD" > product from DEC. > > The reason the project imploded was because apparently DEC stopped > supporting the TCD in RSX11/D in late 1976, so someone in CSS had the > great idea of agreeing to extend the microcode in the DMX11 to handle > both block AND character mode devices. This did.... not work well and it > sank the project. > > What I'm wondering is what was the TCD for PDP11's back then? I don't > see anything in my communications handbooks on this, and even the DMX11 > doesn't really appear, instead there is the COMM/IO/P type boards which > worked with a pile of DZ11's. From what I can glean from this > documentation it looks like the DMX11 worked in a similar fashion as the > requirement was the DMX11 system was a nine board solution (possibly 8 > DZ11's and one controller board). > > More odd it looks like the TCD *was* still supported in RSX11/M and > ultimately the decision was made to build the thing in M so it's weird > they continued to whack away at the DMX solution instead of going with > TCD's for async and proven DMX microcode for block devices. > > Any thoughts, or does this jog any memories? > > C > > > ------------------------------ > > Message: 3 > Date: Sat, 29 Jan 2022 10:24:56 -0500 > From: Paul Koning <paulkoning at comcast.net> > To: Chris Zach <cz at alembic.crystel.com>, "cctalk at classiccmp.org" > <cctalk at classiccmp.org> > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <7F4B4A3F-4114-4FF9-9D6C-28AA7E26E475 at comcast.net> > Content-Type: text/plain; charset=us-ascii > > > > > On Jan 29, 2022, at 12:28 AM, Chris Zach via cctalk <cctalk at classiccmp.org> wrote: > > > > Old question: I'm looking through some old reports from 1977 about a failed DEC project with the DMX11 multiplexer system and there is reference to the following key items: > > > > 1) The DMX was designed to handle block mode devices. Fine. > > 2) Character mode devices like the VT52's were supposed to use a "TCD" product from DEC. > > > > The reason the project imploded was because apparently DEC stopped supporting the TCD in RSX11/D in late 1976, so someone in CSS had the great idea of agreeing to extend the microcode in the DMX11 to handle both block AND character mode devices. This did.... not work well and it sank the project. > > > > What I'm wondering is what was the TCD for PDP11's back then? I don't see anything in my communications handbooks on this, and even the DMX11 doesn't really appear, instead there is the COMM/IO/P type boards which worked with a pile of DZ11's. From what I can glean from this documentation it looks like the DMX11 worked in a similar fashion as the requirement was the DMX11 system was a nine board solution (possibly 8 DZ11's and one controller board). > > > > More odd it looks like the TCD *was* still supported in RSX11/M and ultimately the decision was made to build the thing in M so it's weird they continued to whack away at the DMX solution instead of going with TCD's for async and proven DMX microcode for block devices. > > > > Any thoughts, or does this jog any memories? > > Nothing comes to mind here; the name "DMX" does not ring any bells. It's a bit before my time, admittedly. > > DEC made some products that used block mode terminals: the moderately successful Typeset-11 with the VT-61/t forms and page editing terminal, and the VT-71 with embedded LSI-11 to do full file local editing. Both have some form of block transfer to the host, but as far as I can remember they used ordinary DH-11 terminal interfaces. DH-11 is unusual in that it has DMA in both directions, which is unhelpful for interactive use but great for block transfer. Typeset-11 also supported a specialized terminal made by Harris (the 2200), another local processor device, this one connected to the PDP-11 host with a DL-11/E, using half duplex multidrop BISYNC with modem signal handshakes. I kid you not... I have some scars debugging that protocol at 2 am in downtown Philadelphia. > > DEC also built yet another VT-51 variation, the VT-62, which was the terminal for the TRAX system. That was, I think, some sort of RSX derivative (-M+ perhaps, but I'm not sure), which made it to field test but was canceled before becoming an official product. Not sure why. > > paul > > > > > End of cctalk Digest, Vol 88, Issue 29 > **************************************

4 years, 2 months

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What was a Terminal Concentration Device in DEC's products?

by jnc＠mercury.lcs.mit.edu

> From: Paul Koning > DH-11 is unusual in that it has DMA in both directions McNamara's DH11? (I don't know of another DECdevice of that name.) Per: http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. Noel PS: I am familiar with the term 'terminal concentrator' from the networking world, but as a generic term, not the name of a particular product. (Although Cisco's first boxes may have included a terminal concentrator, so named.) Noel

4 years, 2 months

4
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What was a Terminal Concentration Device in DEC's products?

by cz＠alembic.crystel.com

Old question: I'm looking through some old reports from 1977 about a failed DEC project with the DMX11 multiplexer system and there is reference to the following key items: 1) The DMX was designed to handle block mode devices. Fine. 2) Character mode devices like the VT52's were supposed to use a "TCD" product from DEC. The reason the project imploded was because apparently DEC stopped supporting the TCD in RSX11/D in late 1976, so someone in CSS had the great idea of agreeing to extend the microcode in the DMX11 to handle both block AND character mode devices. This did.... not work well and it sank the project. What I'm wondering is what was the TCD for PDP11's back then? I don't see anything in my communications handbooks on this, and even the DMX11 doesn't really appear, instead there is the COMM/IO/P type boards which worked with a pile of DZ11's. From what I can glean from this documentation it looks like the DMX11 worked in a similar fashion as the requirement was the DMX11 system was a nine board solution (possibly 8 DZ11's and one controller board). More odd it looks like the TCD *was* still supported in RSX11/M and ultimately the decision was made to build the thing in M so it's weird they continued to whack away at the DMX solution instead of going with TCD's for async and proven DMX microcode for block devices. Any thoughts, or does this jog any memories? C

4 years, 2 months

2
1
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simulation of an entire IBM S/360 Model 50 mainframe

by decguy＠songdog.eskimo.com

This might be old news to a lot of people here, but I noticed a fun article on The Register today: Hardware boffin is building a simulation of an entire IBM S/360 Model 50 mainframe https://www.theregister.com/2022/01/27/ibm_s360_simulation/ The article has a handy link to a post on Ken Shirriff's blog: https://www.righto.com/2022/01/ibm360model50.html While I'm kind of a "DEC guy", I still have a certain nostalgic fondness for the IBM System/360, since that was my first in-depth exposure to computer programming.

4 years, 2 months

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Datum Front Panels

by wrcooke＠wrcooke.net

Some years ago I was on a mission to rack mount all my computer and test equipment. I found three front panels at a hamfest that I planned to use. I never did anything with them but still have them. These are from Datum systems, but they appear to be rather hard to find much information on. The short story is, if anyone needs them for something, let me know. I would hate to do away with them if someone needs them. Two of the panels are marked: Datum, inc Rotating Drum Memory 6008 Datum, inc Data Acquisition System 120 The last isn't marked. A picture is here: http://wrcooke.net/FrontPanels.jpg I will likely be moving in a few months and these are on the "get rid of" list. Thanks, Will

4 years, 2 months

2
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Question about DECtape formulation

by go＠aerodesic.com

I've always thought the physical tape wound on a DECtape spool was a fairly conventional 'sandwich' of mylar/oxide/mylar, but a recent 'test' makes me think there is something else involved. I have a number of tapes I'm cleaning (removing dust, etc.)? to make ready to read on a restored (apparently) Astrotype dual DECtape drive and I was 'dressing' the leaders of the tape (removing ragged bits from old use.)? After trimming a wee bit from several tapes (.5 to 1 inch) I did a test.? Taking the bits of tape, I exposed them to various concentrations of isopropanol/water (from about 25% to 99% iso) and found than in all cases, some of the data side of the tape came off on the wipe.? The remaining tape fragment appears intact - the brown oxide was still there but both sides were now the same color, rather than the data side being darker (as were all my tapes before the test.) Was there some kind of 'lubricating' coat on the data side?? It makes sense, but none of my DEC documents or Googling has any mention of lubrication, other than the "...hydro- dynamic lubrication, relying on the viscosity of air to entrain it with the tape and provide the flotation medium." found in an "ELECTROMECHANICAL COMPONENTS & SYSTEMS DESIGN" from November,? 1964. All of my tapes, including DECtape brand, Scotch brand and even a couple of old "Microtape" brand from DEC (before 'dectape' name change) have this feature, so this doesn't appear to be something that appeared recently (as in late in DECtape production or due to old-age in the tapes.) If someone has some detail information on the tape construction, I'd am curious to see it. Thanks,

4 years, 2 months

7
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2 microvax 3800's for sale

by lyokoboy0＠gmail.com

Hello, I had picked up these machines fresh out of high school. I actually worked a deal with the buyer to make payments out of my paycheck for a few weeks till they were paid in full. i have not had the time to focus and get them running. one machine i have had up to the cpu monitor, no internal disk drive. the second machine has some corrosion on the front panel board, where the battery leaked. it iminimal, and the bad battery is removed. open to offers. located in US Florida Looking to sell off excess stuff, i want to focus on my pdp11's and mainframes.

4 years, 2 months

4
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Searching for information reg. IBM 3979 (Expansion module for 3179G / 3192G coax (3270) terminal)

by romietoo9ibi＠xx.vu

Hi! I am the proud owner of a 3192G coax terminal. As I have recently learned, there is an expansion module for the terminal that allows you to attach a mouse and a IEEE-488 pen plotter to the terminal. Some information about it can be found at [1] and [2]. I am searching for people who are in possession of this expansion unit, out of interest how the PCB looks, etc. If you have one, please respond. -Alex [1] http://bitsavers.org/pdf/ibm/3192/GA18-2590-1_IBM_3192-G_Color_Graphics_Dis… [2] http://www.bitsavers.org/pdf/datapro/alphanumeric_terminals/Datapro_C25_IBM…

4 years, 2 months

1
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Old Micro Memory core board

by go＠ao-cs.com

Going through an old junk pile, I came across a couple of core boards: Micro Memory, Inc. PN 90360 8K*8 (MM-6800)? Date code 7725 I have two boards (s/n 202 and 203) so likely purchased in pairs. Anyone have any information on these?? They have 86 pin connectors so not S-100 though connector is about the same size. For years, these have sit on a shelf on my 'round tuit' list of bringing them up in one of my old S-100 boxes, so I've been cruising along thinking these were 100 pin connectors.? I got them out today so I could find the manual (I have used the MMI s-100 8kx8 boards in an old company project back in 1977 and those were about the same size and form.)? The core board is a daughter board on top of the board with the bus connector and is likely the same module from the S-100 board.? I'm guessing the 86 pin bus is a Motorola Exorciser bus - so I can probable figure it out from there, but I would like to find a manual. I think my company had an Exorciser development system in the late 70s.? These were obtained from a dumpster dive.? Pity I didn't get the rest of the box, if so. As usual, google wasn't extremely helpful with old pedestrian hardware searches. -Gary

4 years, 2 months

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Question about DECtape formulation

by jnc＠mercury.lcs.mit.edu

> From: Gary Oliver > I've always thought the physical tape wound on a DECtape spool was a > fairly conventional 'sandwich' of mylar/oxide/mylar ... > Was there some kind of 'lubricating' coat on the data side? It makes > sense, but none of my DEC documents or Googling has any mention of > lubrication ... > If someone has some detail information on the tape construction, I'd am > curious to see it. Dunno if you know of this: http://www.bitsavers.org/pdf/dec/dectape/3M_DECtape_Spec_Nov66.pdf but it doesn't mention any lubrication, just a "Protective Overlay" layer, over the "Coating" (which I assume is the oxide). I'm a bit surprised that "some of the data side of the tape came off on the wipe", though, unless the "various concentrations of isopropanol/water" dissolved the Protective Overlay. Noel

4 years, 2 months

7
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Typing in lost code

by mark.kahrs＠gmail.com

Has anyone ever used Amazon Mechanical Turk to employ typists to type in old listings of lost code? Asking for a friend.

4 years, 2 months

9
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mystery S-100 available

by sieler＠allegro.com

Hi, I have a mystery S-100 computer that I'm would like to sell, from the estate of the late Ken Gielow (author of Z80DIS, a great Z80 disassembler). The proceeds will be donated to a non-tax-deductible magic group Ken was a long-time member of. The computer is located in Cupertino, CA (aka "the heart of Silicon Valley", in the S.F. Bay Area). (If reopened, you can combine a pickup with a visit to the Computer History Museum in nearby Mountain View, CA! :) This would likely be quite expensive to ship. I'd guess 30+ pounds. Photos and some info at: www.sieler.com/ken_photos Some of the hardware (also listed on the above page): ThinkerToys buss unknown semi-transparent front panel spare/uninstalled Ithaca Intersystems DPS-1 front panel 10 various boards inside metal case (heavy) There may be manuals on some of the boards and/or the Ithaca, but I'm not sure yet. (They would be included, if they exist.) I wanted to take photos of each board, but having been seated for about 40 years, they don't come out if I tug gently. None have integrated board lifters, unfortunately (I tried a boroscope, but could not get useful photos.) Based on the labels on some EPROMS, there's a chance that it's a homebrew TRS-80 clone, with both Level II BASIC and CBASIC, and may have Morrow DISCUS software on it. We're looking for an offer on either: - the Ithaca Intersystems front panel; - the computer with all the boards or both. Suggestions welcome, thanks!

4 years, 2 months

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Question about DECtape formulation

by jnc＠mercury.lcs.mit.edu

> From: Gary Oliver > Paul - thanks for the bitsavers reference. Ahem! In any case, it's Al who really deserves the credit, for finding that document, and putting it up. Noel

4 years, 2 months

2
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Typing in lost code

by jnc＠mercury.lcs.mit.edu

> From: Gavin Scott > I think if I had a whole lot of old faded greenbar etc. ... Someone may > even have done this already See: https://walden-family.com/impcode/imp-code.pdf Someone's already done the specialist OCR to deal with faded program listings. Noel

4 years, 2 months

4
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PDP-8 clone built by Canadian company Consolidated Computer Inc

by rodsmallwood52＠btinternet.com

I am trying to locate documentation on the PDP-8 clone built by Canadian company Consolidated Computer Inc (Mers Kutt) in the mid 1970's. An example exists in the UK and will be restored when more data than just the system can be found. Rod Smallwood - digital equipment corporation 1975-1985

4 years, 2 months

1
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Compaq Portable brightness knob

by dave＠661.org

Would someone please suggest a replacement for the Compaq Portable's brightness knob? This was missing on mine when I got it. -- David Griffith dave at 661.org A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

4 years, 2 months

3
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Building a BA08 for a pdp8/L

by cz＠alembic.crystel.com

So now that my pdp8/L is up and running (it now has a serial port and runs FOCAL69 quite well) I'm thinking about the next step, which is of course more memory. This requires a BA08 or BM8/L or something expansion box but to be honest I have enough spare flip chips and such from the wrecked 8/I to build about 3 core memory systems. So given that the schematics for the BA08 are online, they look pretty darn simple, I have the parts, and I have the parts does anyone know if it's possible to get a flip chip backplane to work on and wire up to emulate a BA08? It looks like they just used the data break interface lines to hook up to the processor. Everything's there, Memory address bus, memory data bus, and the various signals for jumps and the like that could allow one to decode and implement the extra instructions needed. Hm. Might just be easier to build it with an FPGA or something as it's mostly linking up simple gates and the whole core memory section could be removed by a 4k*12 memory array. Anyone ever done this? C

4 years, 2 months

2
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VAX 780 on eBay

by jnc＠mercury.lcs.mit.edu

> This: > https://www.ebay.com/itm/275084268137 > ... > Anyway I fully expect it to go ... for a _lot_ more than the opening price. Much to my surprise, it didn't sell at all (although a number of other lots, likely from this machine, did.) I'm rather puzzled that an -11/70 will sell for north of $10K, while a /780 can't fetch $5K. I can only guess that PDP-11'S are seen as more important in the collector world (even though the BSD work, which had such a huge impact on UNIX, which has now - in the form of Linux - taken over the world, was centered on the VAX). Noel

4 years, 2 months

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6
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WARNING: Clear QIC Tape Bands

by lists＠glitchwrks.com

https://i.imgur.com/48EfOQG.jpg That's after sitting parked a couple months. I have a Dysan doing it too. The Dysan had been re-banded with a boiled 3M band and run for years like that with no shedding. I have another Dysan with a green Plastiband in it which is also fine, minimal/no shed. So, I think we may need to re-evaluate if the clear Amazon cheap "plastibands" are perhaps totally incompatible with tape. I know, I know..."just use the band to get data off." But I want to *run* QICs without having to destroy them constantly. Thanks, Jonathan

4 years, 2 months

9
21
0 0

Source for replacement caps in H744 regulators

by robert.jarratt＠ntlworld.com

I think I may need to replace the two output capacitors in some of my H744 regulators. These are screw terminal 6,000uF 10V parts. I have looked on Mouser, Farnell and Digikey and there don't seem to be any available, and any that are listed are really rather costly. Does anyone know where I might find some, preferably from a reputable supplier. Note that I am in the UK. If I can't find 10V rated ones, then, generally up to what sort of voltage rating can I go? Of course, physical size will be a factor, but electrically can it affect operation of the regulator if the rated voltage is too high? Thanks Rob

4 years, 2 months

13
23
0 0

Tiny PDP-11/73 system for sale

by stephen.m.pereira.sr＠gmail.com

I am in the process of thinning down my vintage computer holdings, to relieve some of the burden I will leave to my heirs (hopefully not too soon!). I have a working tiny PDP-11/73 system available for sale. I would much prefer not to have to break it down and pack it for shipping, but I will if the buyer agrees to pay for the packing and shipping costs. - - - - - Tiny PDP-11/73 System: H9281-BA backplane and card cage KDJ11-A CPU DLV11-J 4 port SIO MSV11-LK 256KB/128KW memory Emulex UC07 SCSI interface Power-on Reset board from here: http://www.heeltoe.com/index.php?n=Pcbs.Qbus-por SCSI-to-SD hard drive emulator with 4 drives available, RT-11 installed MeanWell RT-125B power supply 4.5 inch AC fan qty 4 GlitchWorks serial cables Spare PDP-11/23 CPU saved as a backup: KDF11-AB CPU RT-11 Pocket Guide RT-11 Mini-Reference Manual - - - - - I am asking $800.00 for the lot. It cost me about that, probably more to acquire it piece-by-piece and assemble it into a working system. smp - - - Stephen Pereira Bedford, NH 03110 KB1SXE

4 years, 2 months

1
1
0 0

Screws for a Compaq Portable keyboard

by dave＠661.org

Would someone please suggest a suitable screw specification for the Compaq Portable keyboard? My restoration project was interrupted and I managed to lose the screws. -- David Griffith dave at 661.org A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

4 years, 2 months

1
0
0 0

DECnet/10 manuals?

by paulkoning＠comcast.net

I'm looking for a manual I can't find on Bitsavers: a DECnet/10 programming manual. The reason: trying to read PSTHRU.MAC and realizing that I was trying to understand DECnet-10 code while reading the DECnet-20 programming manual. Oops. paul

4 years, 2 months

1
0
0 0

Tiny PDP-11/73 system for sale

by stephen.m.pereira.sr＠gmail.com

I am in the process of thinning down my vintage computer holdings, to relieve some of the burden I will leave to my heirs (hopefully not too soon!). I have a working tiny PDP-11/73 system available for sale. I would much prefer not to have to break it down and pack it for shipping, but I will if the buyer agrees to pay for the packing and shipping costs. - - - - - Tiny PDP-11/73 System: H9281-BA backplane and card cage KDJ11-A CPU DLV11-J 4 port SIO MSV11-LK 256KB/128KW memory Emulex UC07 SCSI interface Power-on Reset board from here: http://www.heeltoe.com/index.php?n=Pcbs.Qbus-por <http://www.heeltoe.com/index.php?n=Pcbs.Qbus-por> SCSI-to-SD hard drive emulator with 4 drives available, RT-11 installed MeanWell RT-125B power supply 4.5 inch AC fan qty 4 GlitchWorks serial cables Spare PDP-11/23 CPU saved as a backup: KDF11-AB CPU RT-11 Pocket Guide RT-11 Mini-Reference Manual - - - - - I am asking $800.00 for the lot. It cost me about that, probably more to acquire it piece-by-piece and assemble it into a working system. smp - - - Stephen Pereira Bedford, NH 03110 KB1SXE

4 years, 2 months

2
2
0 0

Sun 3/260 on eBay; Boston area

by pschow＠gmail.com

Local pickup only. https://www.ebay.com/itm/265510502961

4 years, 2 months

1
0
0 0

seeking Motorola M68MM01A2 documentation

by chrise＠pobox.com

I have quite a few Motorola Microsystems Exorciser boards including this 6800 single board computer for which I am lacking any documentation. I've seen a brochure in Al's collection on Bitsavers but haven't found any details that might discuss jumper settings or even better, a schematic. Wondering if anyone would have a user manual or other detailed docs for this board? M68MM01A2 -- has 6800 CPU, 6875 1.0 MHz clock generator, 6850 ACIA and MC14411 baud rate clock, (4) EPROM/ROM sockets and (2) 6821 PIA sockets with the 86-pin Exorciser edge connector. I'm interested in seeing if I can minimally modify it to have a similar memory map to the Altair 680 so that the Altair's PROM monitor could run on it. Thanks! Chris -- Chris Elmquist

4 years, 2 months

6
20
0 0

AOL diskettes

by athornton＠gmail.com

> From: Grant Taylor <cctalk at gtaylor.tnetconsulting.net> > > I wince at the idea of running with QIC tape. But my experience is with > QIC-80 tapes of the '90s which were so unreliable as to be in the same > category as AOL floppy disks during the late '90s around the transition > to CD-ROMs. As in I would trust an AOL floppy disk to better hold my > data for a week than I would a QIC-80 tape to hold data for a month, > much less a year. ...and I didn't even trust an AOL floppy to go from > computer to computer for 5 minutes. -- Talk about a race to the bottom > for quality. I wish I'd kept some. I had some AOL CDs from slightly later that made decent coasters for decades. Although I guess with the shutter, the floppy wouldn't really have made a very good coaster. Adam

4 years, 2 months

10
14
0 0

IBM 6731 Diskette Module

by organlists1＠sonic.net

Is anyone familiar with the IBM 6731 Diskette Module from around 1984 which gave the IBM Electronic 85 and 95 Selectric Typewriters the ability to store created documents to a 5.25" floppy diskette? There was also a 5.25" diskette which was nicknamed "IPL" for "initial program load", and an interface board which was installed into the typewriter and was referred to as the "IBM Typewriter Modularity Option". I do not have any images of the IBM 6731, but I do have an image capture >from the installation and operations manual, posted here: https://www.dropbox.com/s/us8aely530s8p3a/6731diskettemodule.jpg?dl=0 You do not need a Dropbox account to view the image. Simply click on the X of the login pop up and it will disappear. Unfortunately, the only copy of this product manual I ever found was on eBay. I purchased it last month, paid USPS priority mail shipping with tracking and the post office lost it. :/ Thanks Don Resor

4 years, 2 months

2
2
0 0

IBM 6731 Diskette Module

by organlists1＠sonic.net

Is anyone familiar with the IBM 6731 Diskette Module from around 1984 which gave the IBM Electronic 85 and 95 Selectric Typewriters the ability to store created documents to a 5.25" floppy diskette? There was also a 5.25" diskette which was nicknamed "IPL" for "initial program load", and an interface board which was installed into the typewriter and was referred to as the "IBM Typewriter Modularity Option". I do not have any images of the IBM 6731, but I do have an image capture >from the installation and operations manual, posted here: https://www.dropbox.com/s/us8aely530s8p3a/6731diskettemodule.jpg?dl=0 You do not need a Dropbox account to view the image. Simply click on the X of the login pop up and it will disappear. Unfortunately, the only copy of this product manual I ever found was on eBay. I purchased it last month, paid USPS priority mail shipping with tracking and the post office lost it. :/ Thanks Don Resor

4 years, 2 months

1
0
0 0

Looking for CONAR CCTV TV camera CONAR WERE KITS FROM NATIONAL RADIO COMPANY

by couryhouse＠aol.com

Looking for CONAR CCTV? TV camera CONAR WERE KITS FROM NATIONAL RADIO COMPANY want books parts assembled units whole units? broken units-- I lust for one in the box un-assembled too! anything anything anything? related? toi this? camera? collecting up stories and folklore from others that may have? built one, owned one or? even just lusted? for? one!reply using the? following? ??SMECC CONAR TV CAMERA HISTORY PROJECT?? ? ?as? email reply? title? and? send? to?couryhouse at aol.comdrop me a line off list? with? first? word? CONAR? in subj. line? thx....Thanks in advance and stay well....Ed Sharpe? Archivist? for? SMECC

4 years, 2 months

1
0
0 0

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