- cctalk - classiccmp.org

by Paul Anderson

If you have any questions or wish to contact me, Please email me directly at useddec(a)gmail.com. 42" cab with BA23 microvaxII, plus additional BA23 42" cab with 2 RL02 drives, outer case for 11/23 and you pick which Qbus box you want with it and what boards you want in it. 42"cab with RL02 RAMTEK Marquis model III with Compugraphic monitor HP7475 plotter LA36 with Datasouth board 120cpm LA100 LA12 with carrying case Darkroom equipment including Omega B22, D2, other enlargers, timers, tanks, trays, etc. I can text photos of any of these items and anything I have listed, but have problems posting them. If you have any US or foreign coins or currency, I'm interested in trading for computer equipment. If you are interested in stopping here before or after VCFMW, or when you are in the area, let me know so we can set up a time. I'm outside Champaign, IL, with easy access to I-57, I-72, and I-74. Thanks, Paul

11 hours, 11 minutes

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Anybody need a Pentium III MB?

by Van Snyder

I have a Supermicro P3TDDE MB. It has two processors with their fans, and four USA DEM DO133-065651I 64x64 133-222 memory sticks. Also the ATX plate for the back, and a Matrox dual-VGA graphics card. All yours for a PDF of a shipping label.

19 hours, 36 minutes

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BLACK BOX SP400A-R3 and SP340A-R2 opto isolators

by Holm Tiffe

Hi all, A customer has a problem with an old CNC Mill that uses an LSI11 for control. There is an DEC VT510 connected to the LSI11 as console, The LSI11 is booting from an RX01 (2?) and uses some basic programm.. pretty much a museum... The problem is, that on the Sigma Systems serial Card (similar to the M8043) the AM26LS32 receiver is going bad afer some on/off cycles of the computer. I've already fitted a socket for the 26LS32.. The AM26LS23 only could tolerate +-7V common mode voltage difference and seems to be not the best part for RS232.. I've checked the terminal and changed in the meantime the X2 and X capacitors at the line filter, the protective earth from the Line is connected to the Pin 7 (singal Ground) of the DB25 Connectors and I could'nt measure realy potential differences that could be the cause for the damadge of the receiver chip. To make it short..chase away the problem I wan't to use some RS232 Opto Isolator in the RS232 Line. I've got a used BLACK BOX SP340A-R2 and an SP400A-R3 from Ebay, additional some Power Injector from BLACK BOX for powering that with some wall wart that wasn't included. I've now looking for a Manuals for the BACK BOX SP340A and the SP400A to configure the dip switches in there. There are 2 DIP Switches with 8 positions each..for configuring the power supply for the opto couplers from the DB25 connectors it seems. Haven't found anyithing related on bitsavers, there is blackBox in the communication archive, but nothing related to the SP340 oder SP400.. Can anybody help please? Regards, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 info(a)tsht.de Tel +49 37292 709778 Mobil: 0172 8790 741

1 day, 9 hours

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Someone posted about old "CSM Core" Board on Reddit

by Christian Liendo

It looks like they may be looking to let them go. https://www.reddit.com/r/vintagecomputing/comments/1mv17hn/197274_boards/

2 days, 4 hours

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80386 - 1985

by Murray McCullough

40 years ago this year Intel came out with the 80386 – 386 – or i386. Either seems to be correct. What this meant was a memory address of 4GB, far beyond what an average computer user would need or want, but was so much more than previously(8086, 80286); ‘true’ multi-tasking which for the average computer user didn’t mean all that much; and paging, which made virtualization possible- experimenters were over-joyed! What all this contributed to was the end of the classical/vintage-computing era. Whether this began the time of open-source OS development is debatable! Happy computing? Murray 🙂

2 days, 4 hours

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List of PDP-8 omnibus boards available at VCFMW or shipped.

by Paul Anderson

M1705 M518 M7741 M8342 M835 M8350 M8360 M8357 M8365 M8366 M837 M839 M841 M847 M849 M860 M8650 M8659-YA M865 M8652 M8653 M8655 M866 M868 M884 M885 M880//H241 MR8E-EC Also CR8- an actual DEC card reader interface, dec industrial control equipment,EMEX paper tape interfaces, and other dec compatible boards including memory.

3 days, 3 hours

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PDP-8/s Engineering Drawings?

by Tom Hunter

I have recently bought a DEC PDP-8/s. It hasn't been powered on for about 40 years before I got it. I cleaned it and did some repairs on it (glued broken flip-chip handles, replaced all front panel lights, restored the acrylic front panel to as new condition and built a new switch mode power supply for +10V and -15V). After testing each flip-chip individually for dead shorts on the power rails I reassembled the flip-chips into the backplane and on power up it shows signs of life, but has a number of problems I will have to debug and fix. Does anyone here have the original Engineering Drawings or good PDF scans of the drawings? There are reduced copies of the PDP-8/s Engineering Drawings in Appendix A of the two PDP-8/s Maintenance Manuals on Bitsavers, but I have not been able to find scans of the actual Engineering Drawings. Some details in the reduced copies in Appendix A are not legible. Thank you Tom

3 days, 9 hours

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3.5" DD disks, NOS, $10 pack of 10

by Anders Nelson

Found earlier today: https://www.facebook.com/share/16ubJMkAzw/ I was looking for an affordable source of 720K disks before I sold my 5140 so my instinct kicked in haha. -- Anders Nelson

3 days, 16 hours

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DeVry Trainer exhibited at HOPE

by Jeffrey Brace

Bill Degnan had asked in a previous message about the DeVry Trainer that we exhibited at HOPE_16. The trainer is labeled: De Vry Institute of Technology Bell & Howell Schools We don't have a lot of information about it. Like the year that it was created, who manufactured it, who used it, home many were made, etc. The usual information that you would put on an info card for an artifact. Here is a picture: https://vcfed.org/wp-content/uploads/2025/08/DeVry_Institute_of_Technology_… Enjoy! Jeff Brace

3 days, 18 hours

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Re: VCF/MARCH at HOPE August 15-17

by John Klos

> VCF/MARCH will have 5 tables this weekend Aug 15-17 at HOPE (hope.net > <http://hope.net/?fbclid=IwZXh0bgNhZW0CMTAAYnJpZBExMFdyWUcwTTFHMUkwOHRqNwEeW…>) > in Jamaica, Queens at St. John's University. > Please stop by if you are in the area! > List of artifacts on display: > Lawrence Livermore (in a briefcase), 8080 processor. > Heathkit trainer ET 3400. > TTL Trainer > Devry Trainer > 555 Timer > HP 5036-A > TRS-80 Model III or IV > Commodore PET > IBM P-70 - Luggage > IBM Portable - 5140 > Pong! > Atari 5200 > Bally Astrocade > Fairchild Channel F > We will be promoting our events and local group. I'd love to stop by, but $250 is one hell of an entrance fee. John

6 days, 18 hours

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Re: VCF/MARCH at HOPE August 15-17

by donald donaldwhittemore.com

I went to DeVry. What is a DeVry Trainer?

1 week

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Re: VCF/MARCH at HOPE August 15-17

by donald donaldwhittemore.com

I graduated in 1969. Guess I missed them. :)

1 week

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VCF/MARCH at HOPE August 15-17

by Jeffrey Brace

VCF/MARCH will have 5 tables this weekend Aug 15-17 at HOPE (hope.net <http://hope.net/?fbclid=IwZXh0bgNhZW0CMTAAYnJpZBExMFdyWUcwTTFHMUkwOHRqNwEeW…>) in Jamaica, Queens at St. John's University. Please stop by if you are in the area! List of artifacts on display: Lawrence Livermore (in a briefcase), 8080 processor. Heathkit trainer ET 3400. TTL Trainer Devry Trainer 555 Timer HP 5036-A TRS-80 Model III or IV Commodore PET IBM P-70 - Luggage IBM Portable - 5140 Pong! Atari 5200 Bally Astrocade Fairchild Channel F We will be promoting our events and local group. Jeff Brace

1 week

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24-bin PC clock batteries - who sells?

by Bill Degnan

Looking for the 24-pin PC clock batteries, such as benchmarq p/n: PM346006 Mouser and Digikey is out of stock. Anyone have an adapter or method to make one? Bill

1 week, 3 days

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VCF Montreal Exhibit Registration 2nd Call

by Jeffrey Brace

Register your exhibit with VCF Montreal! There's still spaces left: https://docs.google.com/forms/d/e/1FAIpQLSc4dnGLg9Ubt3gSxNNcOukTIhTNZZK2dQB… VCF Montreal is Jan 24-25, 2026. Jeff Brace

1 week, 6 days

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VCF West 2025 Post Event Survey

by Jeffrey Brace

Did you attend VCF West 2025? Please fill out this survey: https://bit.ly/vcfw2025post The show was a great success with record attendance! Jeff Brace

2 weeks, 1 day

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Anyone used a M5C6847 in place of a MC6847?

by Jim Brain

I have a tube of them here, but they won't do anything in any VDG-based system here. Wondering if it's just broken parts (I have no record of buying them, so must have been someone gifting them to me) or there's something I am missing: http://matthieu.benoit.free.fr/cross/data_sheets/M5C6847P-1.pdf -- Jim Brain brain(a)jbrain.com www.jbrain.com

2 weeks, 4 days

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Me again! RSX-11M manual set

by Peter Ekstrom

Ok, it's me again with another RSX-11M question. I have a nearly complete set in PDF form for 4.2. But I am running 4.8. Is 4.2 close enough or does anyone have a set for 4.8 or maybe even 4.6? In searching around on the 'net I have found a release notes doc for 4.8 but that's it. Thanks! - Peter

2 weeks, 5 days

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Chuck Guzis -- Equipment and Archive

by Chuck Guzis

I am Michael St. Clair, Chuck's nephew by marriage. I'm writing from his account to establish bona fides; apologies for any surprise it might cause. You appear to be the people he considered his professional peers, so I'm reaching out to you for some help. Chuck had little warning before he passed. He left his equipment and development environments in working order, but without a legacy plan. I'm a software engineer and data archivist, and my aunt has asked me to find good homes for his equipment and IP. I'm going to organize and open-source the software and other IP that he hadn't already released. However, I don't know how to safely use, maintain, or even store his physical gear. I'm only in Eugene for a couple more days on this particular trip. is there any specific physical information (that doesn't require disassembly) that might be useful to potential adopters? I don't have time to make a complete inventory, but here's a list of highlights and a Drive folder containing some photographs. This is not (yet) a formal "come and get it" offer, but it's likely a prelude to one (excluding business documents and computers). Highlights: - Multiple 8-inch floppy drives in built-like-a-truck housings - Dozens of assorted 80s and 90s-era I/O devices -- ZIP drives, 5 1/4" readers, etc. - rack-mounted HP 7970B tape drive - another full-height rack-mounted 9-track tape drive with external control panel; no manufacturer or model number on anything I can get to - custom-built 'tape dehydrator' - around a thousand pieces of assorted removable media, primarily 3.5", 5 1/4", 8", CD, DVD, and a variety of late-90s and 00s digital tape formats. Per labels and spot-checks, their contents range from widely-distributed commercial software to Sydex master floppies to lost BASIC dialects to industrial control software in CP/M formats. Basically 25 years of Chuck's professional life and the industry around it. - full electronics workbench with partially-finished projects, including something involving Pertec controllers - a variety of functioning vintage keyboards, from IBM Model Ms to something apparently taken from an industrial control station. Drive folder: https://drive.google.com/drive/u/1/folders/1KUs-x6t4OtzS_b7lxYMM7i-GxNi-QRv3 I'd very much appreciate any input. -- Michael St. Clair

2 weeks, 6 days

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Re: Chuck Guzis -- Equipment and Archive

by Chuck Guzis

On 7/31/25 16:06, Wayne S wrote: > Michael, Chuck was knowyo a lot of us on the Classic Computer Discord. > Everyone was wondering what was going to happen with his collection. > Glad that you’re willing to oversee the disposition of it all. > > Join the discord snd put your post in maybe general channel. > You’ll get a lot of suggestions and probably buyers. > > Here the invite. > 6e39fdc07ab9ac7cfcf7636761aff7f7.jpg > Join the ClassicCMP Discord Server! <https://discord.gg/tKedmSze> > discord.gg <https://discord.gg/tKedmSze> > > <https://discord.gg/tKedmSze> > Thanks, Wayne. I'll do that.

2 weeks, 6 days

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Re: Chuck Guzis -- Equipment and Archive

by Gary Clark

Chuck was also highly active at the Vintage Computer Federation and there are lots of people on this forum who should be able to help or advise. Best wishes to you and his family. From the small amount of contact I had through the forum, he was a special person. https://forum.vcfed.org/index.php?threads/sad-news-chuck-g.1253843/page-4#po st-1459242

3 weeks

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Re: Q about DS3881, N8881 DEC8881..

by Martin Bishop

How available, as NoS rather than pulls, are K559IP1 and its chums 2 & 3 ? Martin -----Original Message----- From: Holm Tiffe [mailto:holm@freibergnet.de] Sent: 01 August 2025 10:45 To: Martin Bishop <mjd.bishop(a)emeritus-solutions.com> Subject: Re: [cctalk] Q about DS3881, N8881 DEC8881.. Martin Bishop wrote: > The 8881 data sheet you reference is identical to the one I found last night, quicker to search than rummage. > ok. > The closest it comes to an output drive specification is in the test conditions for the "0" output voltage. The 17 ma current with 5v supply and 0v4 Vol limit suggests a 270R test load. This is interestingly different from the Qbus use case of 178/383 termination; the Thevinin equivalent being 120R at 3v4 - equivalent to ~25 mA to pull down to 0v4. And, ~22 mA to pull down to 0v8 - the Lo voltage you require, 0v4 being what you would like. Yes, I've read that. > > I am extremely sceptical that bus currents of 70/80 mA are likely, to get 70 mA you need a Thevinin R of ~40R ie three terminators in parallel (61 / 131); many years ago, I could not get two backplane systems to do reliable DMA - never mind three ... However, its in the spec so everyone wants one ... Similarly, getting down to 0v4 with a realistic NPN is a joke, under 0v8 yes but with a Q-bus as load my expectation is only a bit below 0v6. ..german saying "you are heavy on the wood way! (Du bist schwer auf dem Holzweg..yes, I know english for runnaways (englisch für Fortgeschrittene = nonsense)) Thy don't specify bus currents with 70mA, they specify the maximal Output low current that the device could handle ..which has almost nothing todo with the current in the use case Unibus or Qbus. > > If you can obtain K559IP1 I suggest you test them on the bench, they could well be usable. But, yes, the well of old parts is drying out. And, IMHO, some of the requirements in the specs are more what DEC would have liked rather than what they could source. I already have some on stock and.. I own an russian 11/03 equivalent Elektronika E60 with M2 CPU .. worked 5 years before now, stored sine then. As far as I remember the K559IP1 is used there on some boards, and The Bus is a QBUS ..but with metric dimensions even on the connectors. If you are interested here are som pics from the boards: https://www.tiffe.de/Robotron/PDP-VAX/E60/ The Interface Board I4vers3 (И4ред3 in the upper left) E60-06.jpg for the russian RX02 has an K559IP1 (К559ИП1) on the bus side, but nmostly used in this machine are K559IP2 and 3 ..8640 and 8641. So there is no need to test those chips, I know they are working. E60-01.jpg and E60-02.jpg are the CPU Board M2. Regards, Holm BTW: why off-list? [DrB] Your 01 0906Z Aug 25 (below) was off list ... > > Best Regards > > Martin > > -----Original Message----- > From: Holm Tiffe [mailto:holm@freibergnet.de] > Sent: 01 August 2025 09:06 > To: Martin Bishop <mjd.bishop(a)emeritus-solutions.com> > Subject: Re: [cctalk] Q about DS3881, N8881 DEC8881.. > > Martin Bishop wrote: > > > https://forum.vcfed.org/index.php?threads/dec-ttl-part-number-equiva > > le nts.79306/ is a collection of rumours about what DEC 8881's > > > > DS3862 was a National Semi trapezoidal (ie slew rate limited driver), whether that makes a DS3881 a National part is a good question (never found it). > > > > DEC documentation on LSI-11 BusDrivers mentions the 8881 as having DEC order code 957, and describes it as a bus driver. The documentation goes on to say that a 8641 is a 8640 (Bus Rx) integrated with a 8881 (Bus driver); followed by pin out (14p classic TTL NAND pin out) and parametrics. I shall try to find a link to the pdf; I have pp55-58 on A4. > > > > The DS3881 might be an urban myth, perpetuated typo / error ? > > That's my tough too.. > Regarding the russian Datasheet the K559IP1 can source 70mA (an other databook shows 80mA here) that's over the spec of an 8881 as far as I know, the "1972_Signetics_SSI_8400_8800_TTL_DTL.pdf page 2-44" has no value for the max output sink current.. > > It seems that this part is modified from the russians but listet as > DEC Standard and used for the same purpose as the 8881, but it has a > modified Pinout too (2 extra free pins, DIP16 instead of DIP14) > > If found a interesting discussion about the western parts here: > > https://forum.vcfed.org/index.php?threads/dec-ttl-part-number-equivale > nts.79306/ > > I'm a former East-german from "behind the iron curtain"..that's why I'm at least kew of the existence of that equivalent parts. I still know of a source of 8640, 8641 equivalents and I've bought the last 7 8T24 equivalents there. This source is now drying out too... > > Regards, > Holm > > > > > Martin > > > > PS off looking for URLs > > > > -----Original Message----- > > From: Holm Tiffe via cctalk [mailto:cctalk@classiccmp.org] > > Sent: 31 July 2025 20:01 > > To: cctalk(a)classiccmp.org > > Cc: Holm Tiffe <holm(a)freibergnet.de> > > Subject: [cctalk] Q about DS3881, N8881 DEC8881.. > > > > The russians build PDP11's and VAXes. They made chips similar to the special DEC chips. For example there is an K559IP2 which is an DS8640, and there is an K559IP1 and they list an DS3881 as equivalent, 4 NAND gates "standard DEC" Bus driver ..hmm. > > > > 1,2-3, 4,5-6 10,11-9 and 13,14-12. ..input,input-output. 16 VCC, 8 > > GND, > > 7,15 free. It is an 16 pin 300mil DIP. > > > > Now I have problems to find a Datasheet for an DS3881 which is NOT an CCFL Inverter from Maxim/Dallas/Analog but I' pretty shure I've seen such beasts already in the past. > > An DEC8881 is sitting next to an DS8640 on a DLV11 I have in my hands..but this is an DIP14 Chip (similar to an 7401 or an 7439). > > > > What the heck could a DS3881 be? > > > > (DEC Bus drivers are getting rare those days, that's the cause that I've bought those russian chips in the past for cheap.. > > > > Regards, > > Holm > > > > -- > > Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, > > Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 > > info(a)tsht.de Tel +49 37292 709778 Mobil: 0172 8790 741 > > -- > Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, > Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 > info(a)tsht.de Tel +49 37292 709778 Mobil: 0172 8790 741 -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 info(a)tsht.de Tel +49 37292 709778 Mobil: 0172 8790 741

3 weeks

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Re: RSX11M (not PLUS) v4.8 question

by Mark Matlock

Peter, I also had the same problem when using RSX11M instead of M+. Below is a quick Macro-11 program that sends two VT100 escape sequences. The first clears the screen and the second sends the cursor home. It can be easily modified for other terminal types if needed. For command line editing that works with RSX11M, take a look at the MCE command line editor. It is a great DECUS program found on RSX SIG Tape Spring 1989 in [265,1] Best, Mark >TYP CLR.MAC .TITLE Reset VT Terminal .MCALL QIOW$S,EXIT$S .EVEN MSG: .ASCII <33>/[2J/<33>/[H/ LEN = . - MSG .EVEN START: QIOW$S #IO.WVB,#5,#1,,,,<#MSG,#LEN,> EXIT$S .END START >MAC CLR=CLR >TKB TKB>CLR=CLR TKB>/ TKB>TASK=…CLR TKB>// >PIP LB:[1,54]/NV/CO=CLR.TSK >INS $CLR

3 weeks

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Q about DS3881, N8881 DEC8881..

by Holm Tiffe

The russians build PDP11's and VAXes. They made chips similar to the special DEC chips. For example there is an K559IP2 which is an DS8640, and there is an K559IP1 and they list an DS3881 as equivalent, 4 NAND gates "standard DEC" Bus driver ..hmm. 1,2-3, 4,5-6 10,11-9 and 13,14-12. ..input,input-output. 16 VCC, 8 GND, 7,15 free. It is an 16 pin 300mil DIP. Now I have problems to find a Datasheet for an DS3881 which is NOT an CCFL Inverter from Maxim/Dallas/Analog but I' pretty shure I've seen such beasts already in the past. An DEC8881 is sitting next to an DS8640 on a DLV11 I have in my hands..but this is an DIP14 Chip (similar to an 7401 or an 7439). What the heck could a DS3881 be? (DEC Bus drivers are getting rare those days, that's the cause that I've bought those russian chips in the past for cheap.. Regards, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 info(a)tsht.de Tel +49 37292 709778 Mobil: 0172 8790 741

3 weeks

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Ferroresonant transformer mystery

by Tom Hunter

Recently I got a nice and complete PDP-8/s from the US. The power supply uses a ferroresonant transformer which in addition to the standard primary and secondary windings has a separate 2.3H winding connected in series to a 2uF 660VAC capacitor forming a resonant "tank" circuit. The transformer's secondary side and the resonant circuit are operated in saturation. There is a magnetic shunt to prevent the primary side going into saturation as well. It accepts a wide input voltage range, but is very sensitive to the input frequency of 60Hz. This is quite a nice if not elegant design for the period in question, but maybe not the most efficient. As I live in Australia I get 240VAC and 50Hz as opposed to the US 115VAC and 60Hz. I can easily convert our 240VAC to 115VAC with a step-down transformer, but cannot easily supply 115VAC at 60Hz. So I was considering using a step-down transformer to get the 115VAC, but modify the resonant "tank circuit" for 50Hz. Unfortunately there is some magic I don't understand. The resonant frequency of a LC circuit with L=2.3H and C=2uF is about 75Hz not the expected 60Hz. Otherwise I could just solve the standard LC resonant circuit formula for C and plug in 50Hz and 2.3H to get the required C. Obviously ferroresonant transformers are more complex than this former software engineer can grasp. Could any experienced EE with relevant transformer knowledge please chime in and help me understand how to redimension the tank circuit to use 50Hz instead of the original 60Hz input. Obviously I could replace the entire power supply with two modern switch mode supplies to create the two rails, but it would be really nice to keep the original supply and just reversibly adapt it for 50Hz. Thanks and best regards Tom

3 weeks, 1 day

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RSX11M (not PLUS) v4.8 question

by Peter Ekstrom

So, I may just be spoiled from using RSX11M-PLUS and now expect too much from the RSX11M OS. But it seems to me the CLS command would be a nice-to-have, but I am not able to find anything about it. So did that not exist for RSX11M? How does one clear the screen in that environment? -Peter

3 weeks, 1 day

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RP2350 5V Input Tollerant Pins

by Martin Bishop

https://www.raspberrypi.com/products/rp2350/ From postings, I know that folks use the RP2350 for interfacing; the trade press has been shipping news of RP's rev A4 datasheet in volume. The datasheet should tell all. However, the 5V tollerance of the "IO" pins is significant for its simplification of TTL interfacing; the maximum supply and output voltage remains 3v3. See section 14.8.2 (p 1335) et seq - NB the FT indication. Martin

3 weeks, 1 day

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rsts.org -- contact and info for them

by Jay Jaeger

I tried to contact rsts.org using their web site form, but it threw a server error when I tried. I have two pieces of info for them, if they hang out here: 1) The files at http://www.rsts.org/autoindex.php?dir=distros/RSTS_tapes/V_10.0/ and http://www.rsts.org/autoindex.php?dir=distros/RSTS_tapes/V_10.1/ cannot be downloaded: access Forbidden error. 2) I have a product code for the RSTS 10.0 distribution tape (they say "Unknown DEC Product Code" on the index page.) The code on the actual tape is BB-P016P-BC RSTS/E V10.0 INSTALL 16MT9 (Unfortunately, my tape has not yet responded to my attempts to read it - I think the signal that ought to tell the drive it is 1600 BPI PE isn't being recognized by my HP SCSI tape drive - it thinks the tape is 800BPI, but it works OK with other 1600BPI tapes.) JRJ

3 weeks, 2 days

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HP900/735 Ram Modules

by hupfadekroua

Hi all, I‘m looking for Ram modules for my HP9000/735 system. Best Andreas

3 weeks, 2 days

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Re: Wanted: IBM 5324 Monitor

by Jaume López Martin

Hello, I am a collector of old computers and a fellow owner of Datamaster computers. I have seen your CCMP post about wanting to have image output from your 5324. I imagine this computer hasn't been serviced. If you want I could help you to solve both issues. If you still have the computer and want to do something with it, we would first need to diagnose and repair it if necessary. I would guide through the entire process of troubleshooting. After the service, I would instruct you how to get video output through HDMI. Regards, Jaume

3 weeks, 3 days

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IBM SMS cards

by Henk Stegeman

Hi all, I just spotted an auction on eBay for 40 IBM SMS cards. It sold for over $2,000 (!) Does anyone know if this reflects collector value or the value of the gold content? Also, what’s the current value of a set of SMS cold contacts? Thanks, Henk www.ibmsystem3.nl

3 weeks, 4 days

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Scada computers and remote terminal units

by Devin

Greetings, Been a long while since i have posted in on here. I usually discuss my pdp 11 and vax systems. I have decided to pivot my career to scada syatems. The company i am with has some interesting stuff that goes pretty far back. Our custom in house tech is a plc pump controller with a radio connection for data logging and control. Pretty cool, 8051 based, with a version of basic in rom that has scada functions added. The backend servers are just linux systems, although in a modular backplane for easy replacement. I have not read much about this tech outside of what we have in house. Are there other historic scada system computers or technologies that are similar, easily found on ebay for example? Ive seen some mention of old allen bradley stuff, but not much notes on how it would be used remotely in the field, as a remote terminal unit. Any suggestions are appriciated, trying to read more into scada tech outside of my company's tech. Thanks, Devin D.

3 weeks, 5 days

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Re: Scada computers and remote terminal units

by Mark Moulding

Honeywell made a large number of these systems, which were in use in many industries (oil refining, manufacturing of all types, water utility distribution, etc.). They were quite expensive, and PLC manufacturers have made great inroads into that market in the past couple of decades. As a result, some of that equipment is showing up in the surplus market. I found a Honeywell "Orion" console desk being disposed of that I would have loved to take, except that it was truly massive (it must have weighed nearly a thousand pounds!). It was electrically height adjustable (with memory), had mounts for two very large monitors, integrated lighting, cable management, and rack spaces for physical buttons and lights. Actually, a lot of their equipment is pretty massive, especially when compared to current-day PLCs. ~~ Mark Moulding

3 weeks, 6 days

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Sad news re: Chuck Guzis

by John

There's been discussion of this on the VCFed forum, but it doesn't look like anybody's brought it up here yet. Per Mike Brutman, list member Chuck Guzis a.k.a. Chuck(G) passed away recently. He was highly knowledgeable, a full-bore storage expert, and an all-around even-keeled decent sort, and will be missed.

4 weeks

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NeXT Cubes Available

by Bill Degnan

(forgive the dual post with Midatlantic Retro if you're in both groups....) Hello I have been in my spare time messing around with NeXT hardware and I have built three extra working NeXT cube systems (mouse keyboard, computer, display) that I would be willing to let go for less than Ebay prices (look on Ebay for sold status complete systems). Two of them have SCSI2SD hard drives and I have one that still has a working original drive. I don't have any optical disks available, but the optical drives come with the system, untested. There are always caveats to define "works", but basically these are working computer systems that could be connected to a network and they come with a basic Next OS installed. I don't want to ship these if possible. So if you're willing to pick up the system (Landenberg, PA), you can try before you buy and pick the one you want at a discount to Ebay price. Contact me through kennettclassic.com/contact.cfm with your offer/timeline. FIrst come first served. Shipping is available if you want to pay a shipping charge, plus postage. I have shipping boxes. I am going to VCFMW this year, but I am flying there and won't be able to bring them. If you want the cube system delivered to VCFMW, you'd have to find someone to deliver it for you, or have it shipped. I am willing to deliver a system a reasonable distance from the Phila/Baltimore area. Cash, CC, Paypal, check accepted. Bill Degnan 484 732 7041 kennettclassic.com

4 weeks, 1 day

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VCF West 2025 Hotel Block Still Available!

by Jeffrey Brace

What do you mean you haven't booked your hotel room for VCF West 2025? The hotel block is filling up fast! Check out this link for more info: https://vcfed.org/2025/07/22/vcf-west-2025-hotel-still-available/

1 month

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AMIGA/040th – Step Behind the Curtain @ VCF West 2025 @ CHM - Aug 1 &2

by Jeffrey Brace

Travel back to the legendary 1984 CES debut of the Amiga and witness exclusive prototype demos in a fully immersive recreation. Rare Amiga Corp and Commodore artifacts will be on display, along with special presentations celebrating key milestones—including the launch of the Amiga 500 and its pop culture impact, featuring a recreation of the Spielberg-inspired “bedroom computer” scene. Explore the revolutionary NewTek Video Toaster and Flyer in a 1990s editing room, and experience rare Amiga coin-op arcade machines in action. Dive into the vibrant world of European Amiga demos and explore a full lineup of Amiga systems—from original classics to modern enhancements using Raspberry Pi, AmiKit, Vampire, MorphOS, AROS, and AmigaOS 4. Browse Tony’s Amiga Emporium for collectible systems, and check out the latest hardware from A-Eon and AmigaKit, including the A1222, A600GS, and A1200NG. Don’t miss this celebration of innovation and legacy! Show info: https://vcfed.org/events/vintage-computer-festival-west/ Tickets: https://vcfed.org/events/vintage-computer-festival-west/vcf-west-tickets/ Jeff Brace

1 month

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SyQuest disk anyone?

by Peter Ekstrom

I am looking for a 15MB SQ300 disk cartridge in working condition. Anyone have one they wouldn't mind parting with? - Peter

1 month

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PDP-11/93 memory question

by Bill Gunshannon

I have an 11/93 with 2MB of memory onboard. I would like to kick it up to 4MB. I got some memory a while ago that was supposed to be PMI for it but it turned out to be UNIBUS and thus no help. I have some old fashioned QBUS memory module floating around. Will these work to add the missing 2MB or can the 11/93 only use PMI? Would be nice to wake this old box up again. I have this cool Decromancer just crying for somewhere to run. bill

1 month

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Compaq 9.1GB Ultra3 SCSI disks + Hot Plug Drive Trays

by Johan Helsingius

Anyone need Compaq hot plug SCSI drives and/or drive trays (part number 386536-001)? I have 16 of them spare. Julf

1 month

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VCF West 2025 Consignment, Aug 1 & 2, Mountain View, CA

by Jeffrey Brace

Get your items into the system! Print your labels ahead of time! Buy and sell treasures. More info here: https://vcfed.org/events/vintage-computer-festival-west/vcf-west-consignmen… Jeff Brace

1 month

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Endeco Cartridge Reader

by Steve Lewis

Is anyone familiar with the Type 1138SSM Cartridge Reader by Endeco, Inc (of Marion, MA) ? I recently got one, it appears to have an RS-232 interface at the back (and a power cable). I believe it is from around 1989. The cartridge slot has a connector that looks like something an NES might have. That is, it is not a tape, but it is much larger than CompactFlash. If anyone is familiar with these, I'm trying to find some cartridges and any kind of manual on how to interface with the thing. Thanks! Steve

1 month

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RK06/7 manual?

by Mark Kahrs

LSSM is looking for a copy of the RK06/07 Technical Description Manual, EK-RK067-TD-001. If anyone can give or loan it to us, we can scan it as well for public distribution. Thanks.

1 month

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Selling a Wang calculator

by pontus

Hi I know this isn't exactly the right group for this. But I have a fairly uncommon Wang calculator for sale and am not sure where to post about it. I've tried "Vintage Calculators Buy & Sell" on facebook without much luck. I see there is some calculator activity on discord, so I'll post about it there but I'd be happy for suggestion of other venues before I go the E-bay route. Below is the blurb I posted on facebook and here is a link to photos of the thing: https://drive.google.com/drive/folders/1gNdVSsNDxDL1Ukjh13-2ElJXRiWKQ5rx?us… FOR SALE: a Wang 362E electronic calculator in good condition, some scuff marks and light scratches but the inside is clean and looks to be complete. It comes with the 370K programming keyboard with nixie tube display in original dust cover, two card readers model 371 (with feet), four manuals in English and one in Swedish with handwritten notes. Also included is an IBM port-a-punch in box. I have decided not to test it in order to avoid causing any damage from improper handling or due to problems with ageing hardware. Located in Uppsala, Sweden. I will ship internationally but please allow some time for me to package it properly and figure out the best shipping options. I have shipped heavy computers and even CRTs with success, so I’m not without experience. Give me an offer :)

1 month

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9-Track Tape Extraction

by lukeparkerson1＠gmail.com

Hi all, I recently got my hands on what I believe is a 9-track tape, dated 1986, which has some old survey data stored on it from a university research project several decades ago. I'm hoping to be able to extract the information from the tape and convert it to a more modern data file accessible to the public, but I don't know very much about these tapes nor do I have 9-track tape equipment. I'm wondering if anyone who is more familiar with this technology can tell me it's even still possible to extract this data, and if so, is there's anyone here who can try and run the tape, or knows someone with a working 9-track tape drive? The frame is not in the best shape, but the tape is hopefully fine. Here's a photo: https://drive.google.com/file/d/1PrdBnIWUO4-317ZSwqvY-TD6dHr2CxC8/view?usp=… Thanks, Luke

1 month

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Re: Lee Felsenstein at VCF West August 1 at 4:30PM

by John Foust

At 04:22 PM 7/10/2025, you wrote: >Lee Felsenstein at VCF West Friday, August 1 at 4:30PM. >He will talk about the 50th Anniversary of The Homebrew Computer Club. Here's the line-up: https://vcfed.org/events/vintage-computer-festival-west/vcf-west-speakers/v… Not just Lee... but also Bob Marsh of Processor Tech, and Harry Garland of Cromenco, and Dan Sokol of Apple... And then for the Amiga 40th events, Dale, RJ, Trevor, Perry, Willie, Marco, Bill, Aaron, Brad, and me, too! And Sellam is there! - John

1 month

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Comstar System 4 Intel 4004 based Industrial Computer Documentation

by Christian Liendo

I was able to obtain a number of documents that pertain to the Comstar System 4. I spoke about this computer in the past but I have scanned some documentation that should help explain this unique computer People who have been interested in the Intel 4004 might find this interesting The Comstar System 4 Reference Manual is rather detailed on the computer itself and it's applications This is the Complete Comstar System 4 Reference Manual https://archive.org/details/comstar-system-4-reference-manual_202507 Warner & Swasey Reference Manual https://archive.org/details/warner-swasey-comstar-star-system-reference Comstar System 4 Programming Manual https://archive.org/details/comstar-system-4-programming-manual Comstar System 4 Tester Manual https://archive.org/details/wscomstar-system-4-test-manual Comstar System 4 CPU Module Schematic https://archive.org/details/comstar-system-4-cpumodule Comstar System 4 Serial Communications Schematic https://archive.org/details/comstar-system-4-serial-communications Comstar Star System 4 RAM Module Schematic https://archive.org/details/comstar-star-system-4-rammodversion Comstar Star System 4 HTL I/O DATA Module Schematic https://archive.org/details/comstar-star-system-4-iodatamodule Comstar Star System 4 PROM Module Schematic https://archive.org/details/comstar-star-system-4-prommodule Comstar Star System 4 PROM 1k 2k Module Schematic https://archive.org/details/comstar-star-system-4-prom-1k-2k-module Warner & Swasey Comstar System 4 Process Control Language https://archive.org/details/wscomstar-system-4-pclref-manual Warner & Swasey Computer Division Comstar System 4 Machine Language / Assembly Language Reference Manual https://archive.org/details/wscomstar-system-4-assembly-language Comstar System 4 Program Analyzer Reference Manual https://archive.org/details/comstar-system-4-reference-manual Computer History Museum's Archive of the Manual https://www.computerhistory.org/collections/catalog/102686568 Comstar Computer Systems Process Control Language Data Sheet https://archive.org/details/comstar-star-pclcompiler-data-sheet

1 month, 1 week

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Video: Introduction to Chiptunes by Inversephase @ VCF East2025

by Jeffrey Brace

Introduction to Chiptunes by @inversephase video released today (7/14/2025): https://youtu.be/i0v712l2RWE Enjoy! Jeff Brace

1 month, 1 week

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Interact One Message Center

by Steve Lewis

Hey all, I'm trying to track down a manual or instructions for the Message Center program on the Interact One (from 1978). I've run this in the MAME emulator, and it seems the program has a "partial" BASIC-like interpreter. You can do line numbers, like 10 HELLO 20 WORLD Then issue the command SCROLL, and it will start scrolling text in the numeric sequence they were specified. Then you can also do commands like FLASH, BUZZ, BEEP in its equivalent of "immediate mode" -but I don't know yet how to specify these commands in the numeric program. And in the emulator, I can't yet parse the commands PLOT, SOUND, SIZE - these "message center" program specific commands,not BASIC (BASIC on this system is loaded from tape). Anyway, a manual on a program for the Interact One called "Message Center" is what I'm trying to track down. Thanks, Steve

1 month, 1 week

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IBM System/23 Datamaster 5324 Towers and IBM 5247 HDD Tower Available

by Ali

Hello All, A long time ago I acquired a System/23 desktop unit and eventually a number of the tower units including the HDD tower unit. The plan was to setup a System/23 Muli-User system with multiple terminals connected together. Well, like many great plans real life got in the way and the units have been sitting in storage for a few years. I have accepted that this is one of the projects I will never get to and it is time to pass them on to someone else who can enjoy them. The systems are in SoCal (Upland, CA to be more exact). More info can be found at the following links: https://forum.vcfed.org/index.php?threads/ibm-system-23-datamaster-5324-towe r-model-of-the-5322-with-original-clicky-keyboard.1253651/ https://forum.vcfed.org/index.php?threads/ibm-system-23-datamaster-5324-towe r-model-of-the-5322-with-one-floppy-drive.1253652/ https://forum.vcfed.org/index.php?threads/ibm-system-23-datamaster-5322-or-5 324-hdd-tower-model-5247.1253653/ I hate to part/scrap them as the towers rarely show up so I am hoping someone local would be interested in them. Feel free to email me directly or reach out through VCF. Thanks -Ali

1 month, 1 week

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