Re: Odd Connections to Rectifier?

On 2017-Dec-18, at 12:06 AM, Rob Jarratt via cctalk wrote: > I am reverse engineering the schematic for the input stage of my H7862 PSU. > I have come across a KBU6J bridge rectifier which seems to be connected only > to the two middle pins, which are the AC inputs. I can't see any other > connecti

[cctalk] Re: 1974 No Name Terminal

On 2023-Jul-05, at 8:25 AM, Brad H via cctalk wrote: > Seems to be RS-232 compatible, which in my experience is unusual for a > terminal in the early half of the 1970s. It has little serial number > stickers tucked around but they're all random numbers, nothing really lines > up. A few of the

[cctalk] Re: 1974 No Name Terminal

On 2023-Jul-05, at 9:45 AM, wrote: > Thank you! I couldn't remember if I'd posted it here before, I've been off > the list for a while. > > Because I don't know really anything about it, I'd been operating on the > belief the power sent from the PSU was DC. So maybe that's my issue. There >

[cctalk] Re: NGPL TCS - 1969 Industrial Control

On 2023-Aug-20, at 5:32 PM, Eric Moore via cctalk wrote: > https://youtu.be/-CaUafVqnbw > > Super stoked to be able to share my latest video, I hope yall like it. > > -Eric I'll third Ken and Rick's comments. Nice to see this restored as its original-use system - the CPU together with the pro

[cctalk] Re: Concorde cabin display technology?

On 2023-Sep-16, at 8:52 AM, Shoppa, Tim via cctalk wrote: > Not quite computer tech but I figure this is the best place to ask: > > Does anyone recognize the display tech that was used on the Concorde's > in-cabin display? > > Examples: > https://samchui.com/wp-content/uploads/2016/02/CON15.jpg

[cctalk] Re: Theory of operation of DEC H7441 regulator?

On 2023-Sep-27, at 9:01 PM, Tom Hunter via cctalk wrote: > The DEC H7441 regulator is a relatively complex circuit using 2 x 555 > timers, 2 x LM301 op-amps, 2 x transformers and 2 inductors > I am struggling to understand how it is meant to work and was hoping to > find a maintenance manual for it

[cctalk] Re: Theory of operation of DEC H7441 regulator?

On 2023-Sep-28, at 12:29 AM, Brent Hilpert via cctalk wrote: > ... > Excessive current through Q5 produces a V-drop across R10 which may turn on > Q7 to take the PWM-mono into reset (E2.4=low). > D7,D8,R3 clamp and sink reverse voltage/energy from the T1 secondary to avoid > re

[cctalk] Re: Theory of operation of DEC H7441 regulator?

On 2023-Sep-28, at 3:55 AM, Tom Hunter wrote: > Thank you very much Brent !!! > > Your explanation beautifully clarified how the H7441 works. > I have asked the same question over at vcfed.org without an answer.. > I hope it is Ok to share to vcfed.org what you wrote as others are likely to > str

[cctalk] Re: Intel 4004

On 2023-Nov-21, at 1:03 AM, ED SHARPE via cctalk wrote: > On Mon, Nov 20, 2023 at 7:01 PM ben via cctalk wrote: >> On 2023-11-20 5:36 p.m., Murray McCullough via cctalk wrote: >>> On Nov. 15, 1971 Intel commercially released the 4004 microprocessor which >>> some consider to be the first. Nonethel

[cctalk] Re: oscilloscopes

On 2024Apr 1,, at 3:33 PM, Just Kant via cctalk wrote: > > I have more then I need. All the working ones are HP w/color crts, and as far > as older, verifiably vintage tools (right down to the 680x0 processor in > either) I have to admit I favor them as a brand. Call we an oddball, weird > egg

[cctalk] Re: oscilloscopes

> On 2024Apr 4,, at 7:22 AM, Adrian Godwin via cctalk > wrote: > > This 'scope clock also uses circle generators rather than vectors to > produce well-formed characters. It mentions a Teensy controller so I don't > think it's the original made in this way - the first I heard of was too > long ag

[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)

On 2024May 31,, at 4:37 PM, Murray McCullough via cctalk wrote: > On Fri, May 31, 2024 at 6:02 PM Dave Dunfield via cctalk > wrote: >> Liam Proven wrote: >>> It needs to have a microprocessor to qualify. >>> ... No µP = not a PC. >> >> Not entirely sure ... >> http://dunfield.classiccmp.org

[cctalk] LCM auction pre-notice

Just received a message from a friend mentioning stuff from the LCM is to be in a Christie’s auction in Aug-Sep. Online auction, viewing in Seattle by appointment. https://www.christies.com/auction/firsts-the-history-of-computing-from-the-paul-g-allen-collection-23618-nyc

[cctalk] LCM auction

Christies lot listings for the Paul Allen / LCM stuff are now up. Pretty sad to see such a collection of notable items broken up. The web presentation is a little confusing. I think it breaks down like this: Intro / overview: https://www.christies.com/en/stories/paul-allen-computer-collection-d9

[cctalk] Re: auction starting in 50 minutes

This lot-group is closed. Sale prices were insane. https://onlineonly.christies.com/s/firsts-history-computing-paul-g-allen-collection/lots/3726 (In my estimation) a few items went for high

[cctalk] Re: auction starting in 50 minutes

On 2024Sep 12,, at 7:24 PM, Glen Slick via cctalk wrote: > > On Thu, Sep 12, 2024, 6:13 PM Adrian Stoness via cctalk < > cctalk@classiccmp.org> wrote: > >> WaIt someone paid 23k for a asr33? > > Price Realised USD 23,940 > > Does that include the 26% buyer's premium, or is that another $6,224

[cctalk] The ultimate nerd fashion accessory

https://apollo-instruments.com Groan. Spoiler: Wristwatch DSKY

Re: Another IC I Can't Identify

On 2018-Nov-11, at 11:52 AM, Rob Jarratt via cctalk wrote: > Thanks for all the replies. If that is indeed what it is, then I still have > not been able to find the source of one of the signals that seems to be > causing the Reset, every pin I have found so far is an input, I have not > found it

Re: Another IC I Can't Identify

On 2018-Nov-11, at 1:32 PM, Rob Jarratt wrote: >> -Original Message- >> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Brent >> Hilpert via cctalk >> >> On 2018-Nov-11, at 11:52 AM, Rob Jarratt via cctalk wrote: >>> Thanks for all

Re: Another IC I Can't Identify

On 2018-Nov-11, at 2:04 PM, Rob Jarratt wrote: >> -Original Message- >> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Brent >> Hilpert via cctalk >> Sent: 11 November 2018 21:50 >> To: General Discussion: On-Topic and Off-Topic Posts &g

Re: Battery warning in Falco terminals

On 2018-Nov-19, at 3:29 PM, Al Kossow via cctalk wrote: > I've been helping the MAME guys simulate a TS-2624, which is a block mode HP > emulating terminal. > I had bought this a while ago, and never dumped the firmware. Unfortunately > there is a large > NiCd battery right in the middle of the

Re: Battery warning in Falco terminals

On 2018-Nov-20, at 5:11 AM, Al Kossow via cctalk wrote: > On 11/19/18 11:54 PM, Brent Hilpert wrote: > >> I didn't have need / get as far as doing an I/O map or memory map for the >> Z80. >> >> Should I send these files along? >> > > Yes, please to dumps/docs and board/terminal pics from you a

Re: Battery warning in Falco terminals

On 2018-Nov-20, at 1:21 AM, Mike Stein via cctalk wrote: > - Original Message - > From: "Al Kossow via cctalk" > To: "General Discussion: On-Topic and Off-Topic Posts" > Sent: Monday, November 19, 2018 6:29 PM > Subject: Battery warning in Falco terminals > ... >> Also, I suspect the fi

Re: Battery warning in Falco terminals

On 2018-Nov-20, at 11:42 AM, Al Kossow via cctalk wrote: > On 11/20/18 11:28 AM, Brent Hilpert via cctalk wrote: > >> Were there 3 PROMs on the TS-1? I don't remember > > There are three bipolar proms on the 2624 that you can see on the pcb picture > I still need

Re: Battery warning in Falco terminals

On 2018-Nov-20, at 11:18 AM, Paul Koning wrote: >> On Nov 20, 2018, at 2:07 PM, Brent Hilpert via cctalk >> wrote: >> >> ... >> The PCB-transformer key design is novel, but (in the TS-1) so is the >> scanning & communication. >> There is n

Re: CDC floppy disks on Ebay.

On 2018-Dec-09, at 2:06 PM, Adrian Graham via cctalk wrote: >> On 9 Dec 2018, at 21:40, Mattis Lind via cctalk >> wrote: >> >> Don't know if this worth saving. https://www.ebay.com/itm/283294561797 >> >> 8 inch CDC disks from 1982. Maybe something interesting? > > It might be just me, but thos

Original AGC restoration / was Re: Apollo 8 Mission Control printers, or not?

On 2018-Dec-28, at 4:43 PM, Adrian Stoness via cctalk wrote: > have u seen the agc being fired up videos Yes, videos from list member curiousMarc : Episode 1: https://www.youtube.com/watch?v=2KSahAoOLdU He's up to Episode 5, the others should show up in subsequent links from the 1st.

Re: Mounting HP7970e 9-Trk 1/2" Tape Drive

On 2019-Feb-04, at 3:40 PM, Jack Harper via cctalk wrote: > > I am mounting a couple of heavy (130-pounds each) HP7970e tape drives to a > 19" rack. > > The screw holes that mate to the standard spaced holes on the right side of > the drive after you open the case are visible and obvious. > >

Re: PDP-11/45 RSTS/E boot problem

On 2019-Feb-06, at 10:53 AM, Noel Chiappa via cctalk wrote: > > I'm not sure that's going to tell us much: the latest development is that > Fritz looked at the actual memory contents again, and it is once again > trash; _almost_ identical to what was there before: > > PA:171600: 016162 004767 00

Re: PDP-11/45 RSTS/E boot problem

On 2019-Feb-06, at 1:21 PM, Noel Chiappa via cctalk wrote: >> From: Brent Hilpert > >> what about the refresh circuitry of the memory board? >> ... >> It might also explain why a number of 4116s were (apparently) failing >> earlier in the efforts ... replacing them might have just replaced them >>

Re: Mounting HP7970e 9-Trk 1/2" Tape Drive

On 2019-Feb-06, at 12:24 PM, Chuck Guzis via cctalk wrote: > On 2/6/19 11:25 AM, Jay West wrote: > >> Yes, it's all "standard 19 inch" but. the HP gear and mounting >> kits of that time expected certain things to be present in the rack >> design/construction well beyond just the space betwe

Re: PDP-11/45 RSTS/E boot problem

On 2019-Feb-06, at 5:11 PM, Fritz Mueller via cctalk wrote: >>> On Feb 6, 2019, at 2:24 PM, Brent Hilpert via cctalk >>> wrote: >>> >>> Is the schematic available for the memory board at-issue? >>> Curious myself to see what approach for

Re: PDP-11/45 RSTS/E boot problem

On 2019-Feb-06, at 3:39 PM, Fritz Mueller wrote: >> On Feb 6, 2019, at 2:24 PM, Brent Hilpert via cctalk >> wrote: >> >> Is the schematic available for the memory board at-issue? >> Curious myself to see what approach for refresh DEC used. > > Yes, here:

Re: PDP-11/45 RSTS/E boot problem

On 2019-Feb-06, at 5:29 PM, Paul Koning wrote: >> On Feb 6, 2019, at 8:25 PM, Brent Hilpert via cctalk >> wrote: >> On 2019-Feb-06, at 5:11 PM, Fritz Mueller via cctalk wrote: >>>>> On Feb 6, 2019, at 2:24 PM, Brent Hilpert via cctalk >>>>> wr

Re: Mounting HP7970e 9-Trk 1/2" Tape Drive

On 2019-Feb-06, at 4:19 PM, Chuck Guzis via cctalk wrote: > On 2/6/19 2:29 PM, Brent Hilpert via cctalk wrote: > >> (I take it you mean "now look at the -left- side".) > > Well, you know, my *other* right... :) > >> However, looking at my 7970A, it a

Re: Mounting HP7970e 9-Trk 1/2" Tape Drive

On 2019-Feb-06, at 7:48 PM, Chuck Guzis via cctalk wrote: > On 2/6/19 6:33 PM, Brent Hilpert via cctalk wrote: > >> Granted you could drill the holes from the rear of the flange, >> however from what I can see the hinge design doesn't look like it >> will allow the

Re: PDP-11/45 RSTS/E boot problem

On 2019-Feb-06, at 10:37 PM, Fritz Mueller via cctalk wrote: >> 4116 datasheet specs 2mS, my calcs give a refresh period of 1.5mS, the >> 14.5uS from the manual would give 1.86 mS, 7% shy of 2. >> The schematic specs 1% resistors, and the parts list does appear to spec a >> high-tolerance "1%200

Re: BASIC for HP 1000, 21xx series

On 2019-Feb-24, at 2:03 AM, GerardCJAT via cctalk wrote: > Back in ''70, sometimes we were running "basic" BASIC ( NOT Time sharing ) on > 2116B, 2100A, just for FUN. > > Is there some copy still around ?? > > I had a look in Google, Bitsavers, HPmuseum, with NO success. > > Thank for help and

Re: 1983 UBC PDP-11 Unix tools distribution

On 2019-Mar-05, at 8:36 PM, Warner Losh via cctalk wrote: > On Tue, Mar 5, 2019 at 5:17 PM Al Kossow via cctalk > wrote: >> On 3/5/19 5:16 PM, Al Kossow via cctalk wrote: >>> Today's tape recovery gem. UBC's PDP-11 UNIX tools distribution ca. 1983 >> >> oh.. and Bill Webb's name is all over this

Re: 1983 UBC PDP-11 Unix tools distribution

On 2019-Mar-05, at 10:07 PM, Richard Loken wrote: > On Tue, 5 Mar 2019, Brent Hilpert via cctalk wrote: > >> TRIUMF was using /11s for cyclotron control I believe, that's not where you >> anticipate UNIX showing up. > > But was it Unix or something else

Re: Pioneers of computing

On 2019-Mar-10, at 3:59 PM, Will Cooke via cctalk wrote: >> On 3/10/2019 3:18 PM, Murray McCullough via cctalk wrote: >>> Back in 1965 Jack Kilby, Jerry Merryman and James Van Tassel at texas >>> Instruments created an integrated circuit designed to replace the >>> calulator. Historians, though not

Re: Pioneers of computing

On 2019-Mar-10, at 5:16 PM, Al Kossow via cctalk wrote: > On 3/10/19 2:18 PM, Murray McCullough via cctalk wrote: >> Historians, though not all, credit this development as the >> beginning of the electronic-computing revolution that was truly underway by >> the mid-70s. > > Scotty, more power to t

Re: Thinking about PDP11 PC05 Emulation

On 2019-Mar-11, at 2:37 PM, allison via cctech wrote: > On 03/11/2019 02:11 PM, Jay Jaeger via cctech wrote: >> I have several PDP-11's in my collection (among other things), and not >> enough PC05 tape readers (or enough room) to go around. But most if not >> all of my machines have M7810 PC11 in

Re: Thinking about PDP11 PC05 Emulation

On 2019-Mar-11, at 2:37 PM, allison via cctech wrote: > On 03/11/2019 02:11 PM, Jay Jaeger via cctech wrote: >> I have several PDP-11's in my collection (among other things), and not >> enough PC05 tape readers (or enough room) to go around. But most if not >> all of my machines have M7810 PC11 in

Re: DEC RC25 / CDC 9457 lark disc

On 2019-Mar-12, at 1:21 AM, shad via cctech wrote: > I always have been amazed by the complexity and peculiarity of > fixed/removable hybrid discs like DEC RC25 and CDC 9457. > Looking at some specifications found on the web, these drives look quite > similar each other, even if these are compl

Re: What 6502 macro assembler was used for the AIM-65 Monitor ROM?

On 2019-Mar-22, at 11:14 AM, Chuck Guzis via cctalk wrote: > On 3/22/19 10:28 AM, Glen Slick via cctalk wrote: >> On Fri, Mar 22, 2019 at 9:59 AM Chuck Guzis via cctalk >> wrote: >>> >>> At the expense of being boo-ed for this, could the original Rockwell >>> stuff perhaps have been assembled usi

Re: Only never in Canada - dumb terminals - video tex

On 2019-Mar-24, at 3:14 PM, ben via cctalk wrote: > On 3/24/2019 10:27 AM, Mike Stein via cctalk wrote: >> And I have some in Toronto; Falco, ADM-11 and bits & pieces. > Did anyone out there (In Canada) buy the surplus VideoTex terminals, > I saw Many Many years ago. Like this?: http:/

AGC restoration / was Re: PDP-8 signed overflow detection - Apollo guidace computer

On 2019-Mar-26, at 9:28 AM, Noel Chiappa via cctalk wrote: >> From: Ben Bfranchuk > >> Now they seem to have have found a SCRAPPED Apollo guidance >> computer and am rebuilding the missing pieces. > > Wow. What a great site (and that guy has mad skills, everything from > repairing old Teletypes,

Re: Yes there is a PDP 10 front panel and Kenbak on Ebay

On 2019-Apr-03, at 11:17 PM, Pontus Pihlgren via cctalk wrote: > Could you provide an URL. ebay search works (or not works) in mysterious > ways. https://www.ebay.com/itm/Digital-Equipment-PDP-10-Control-Console/183760017149 https://www.ebay.com/itm/ULTRA-Rare-Vintage-ORIGINAL-KENBAK-1-aka-CTI

AGC DSKY auction / was Re: Control Console, but not PDP-10

On 2019-Apr-11, at 10:04 PM, Paul Birkel via cctalk wrote: > > Now consider a DSKY. Currently at $27,500.00. Auction estimate: $60,000+ > Great provenance! “The DSKY that saved Apollo 14.” > > https://www.rrauction.com/bidtracker_detail.cfm?IN=5222 I looked up this auction too, after Marc me

Re: "arx-149" computer. .. what Is?

On 2019-Apr-15, at 12:16 PM, ED SHARPE via cctalk wrote: > It is in a metal suitcase appears to be military analog computer Ed! > > On 4/14/2019 5:44 PM, Sam O'nella via cctalk wrote: >> Is there a specific reference you have for this? >> >>> On Apr 14, 2019, at 2:16 AM, ED SHARPE via ccta

Re: "arx-149" computer. .. what Is?

On 2019-Apr-15, at 1:29 PM, William Donzelli wrote: >> It doesn't show up here: >> >> https://en.wikipedia.org/wiki/List_of_military_electronics_of_the_United_States > > I think 99.99mumble percent of JETDS systems ("AN/") do not show up on > that list. > > I have a 1972 edition of one of

Re: Plane of core memory

On 2019-Apr-17, at 9:47 PM, Grant Taylor via cctalk wrote: > On 4/17/19 10:30 PM, Andrew Luke Nesbit via cctalk wrote: >> Hello all, > > Hi, > >> I have been wanting to acquire a plane of magnetic core memory as a piece of >> computing history. My partner actually thinks they look very beautifu

Re: Plane of core memory

On 2019-Apr-18, at 8:47 AM, Jon Elson wrote: > On 04/18/2019 04:49 AM, Brent Hilpert via cctalk wrote: >> It's a 4-wire 3D planar array. By topology and construction I would guess it >> date it from the 60s. > Make that EARLY '60s. As soon as somebody figured out t

Re: Plane of core memory

On 2019-Apr-18, at 9:30 AM, Chuck Guzis via cctalk wrote: > On 4/18/19 9:02 AM, Jim Manley via cctalk wrote: >> Jussi Kilpelainen's page cited above ( >> https://www.tindie.com/products/kilpelaj/core-memory-shield-for-arduino/) >> refers to the work of Ben North and Oliver Nash to create another co

that AGC DSKY auction

So it appears it went for 168 K$ at hammer. With buyer's premium, that puts the sale price at 210 K$. https://www.rrauction.com/bidtracker_detail.cfm?IN=5222

Re: M7264 Troubleshooting

On 2019-May-19, at 9:09 PM, Glen Slick via cctalk wrote: > On Sun, May 19, 2019 at 8:05 PM Mister PDP via cctalk > wrote: >> >> After that, I decided to try and find out why the >> Run/Halt light was not coming on when I hit the switch. Looking at the H11 >> schematics, the light relies on the SR

Re: M7264 Troubleshooting

On 2019-May-20, at 12:11 AM, Glen Slick via cctalk wrote: > On Sun, May 19, 2019 at 11:48 PM Brent Hilpert via cctalk > wrote: >> >> Except the SRUN (K8 SRUN L) action is not latched, so it probably appears as >> an >> active-low heartbeat pulse with some period

Re: M7264 Troubleshooting

Didn't this start out with the RUN LED not lighting up? I don't recall it being mentioned that that was repaired. Perhaps pursue fixing that - while it may be a secondary problem that doesn't resolve a 'bigger' problem, it could be that it uncovers a common problem.

Re: Abandoned FACOM system in Italy?

On 2019-May-27, at 5:53 PM, Glen Slick via cctalk wrote: > On Mon, May 27, 2019 at 4:14 PM shad via cctech > wrote: >> >> Hello, >> do you know the people who made the video? >> I think the factory is the Satilai in Saronno. >> >> Andrea > > I believe those guys are based somewhere in the U

Re: Kids these days...

On 2019-Jun-10, at 11:11 AM, Mark J. Blair via cctalk wrote: > I wouldn’t invest in an IoT buzzword company whose web page admits that the > products they are talking about don’t exist yet, headed by a non-engineer, > even without the fishy international money laundering smell. It’s interesting

Re: Margaret Hamilton Guardian interview.

On 2019-Jul-13, at 1:48 PM, Lyndon Nerenberg via cctalk wrote: > Another of the un-acknowledged people in the upcoming July 29 > 'celebrations'. > > https://www.theguardian.com/technology/2019/jul/13/margaret-hamilton-computer-scientist-interview-software-apollo-missions-1969-moon-landing-nasa-wom

Re: Resurrecting integrated circuits by cooking them.

On 2019-Jul-24, at 10:31 AM, Jeffrey S. Worley via cctalk wrote: > Yesterday evening, in the process of refurbishing five very badly > treated Atari 800 computers I had a hunch and subjected a failed Pokey > chip (Atari Part CO12294 Wikki link https://en.wikipedia.org/wiki/POKEY >) to high hea

Re: Ill NLS MS-230

On 2019-Jul-29, at 6:34 PM, Jim Brain via cctalk wrote: > I have an ill NLS MS-230 Miniscope. Is there anyone on list that might be > interested in getting it running for me? I'm willing pay for the privilege. > I'd like to see the unit working, but I have no experience with analog > scopes,

Re: XXDP on PDP-11/03

On 2019-Aug-14, at 1:26 PM, Allison Parent via cctalk wrote: > IPhoned it in! > >> On Aug 14, 2019, at 2:19 PM, Noel Chiappa via cctalk >> wrote: >> >> From: Jonathan (systems_glitch) > >> Yep, fun times on LSI-11/2! > > Heh, this one was _utterly trivial_ compared to the 'must have working m

Re: GW-DEC-1: A New DEC Prototyping Board

On 2019-Aug-16, at 11:56 AM, systems_glitch via cctalk wrote: > On Fri, Aug 16, 2019 at 2:53 PM Paul Koning wrote: >> >>> On Aug 16, 2019, at 2:43 PM, systems_glitch via cctalk < >>> >>> I'm sure DEC wouldn't have bothered with hard gold plating if their >>> connectors were metallurgically incom

Re: Cassette Interface Assistance

On 2017-Feb-28, at 7:55 AM, Jim Brain via cctalk wrote: > Analog, which is my nemesis, curses me again. > > I have a cute idea for a cassette port project for the Tandy line of > computers (the ones with the cassette port). I have a Coco 3 on the bench, > so I scoped the output line while doing

Re: Magtape write rings [Was: Re: Full immersion emulation]

On 2017-Mar-05, at 11:27 AM, Chuck Guzis via cctalk wrote: > On 03/05/2017 10:41 AM, Mark J. Blair via cctalk wrote: >> >> So, was the write enable state latched at some point in the loading >> cycle on those drives? That surprises me, because I would have >> expected the write enable sensor to in

Re: Univac I memory tank

On 2017-Mar-14, at 2:41 PM, Noel Chiappa via cctalk wrote: >> From: Dwight Kelvey >> I need on of those. > > I think it belongs in a museum, actually. Provided they can make it work, of > course! :-) I wonder how many working delay line main memories are left in > the world? Depends on how partic

Re: 8085 RESET

On 2017-Mar-18, at 5:21 PM, Adrian Graham via cctalk wrote: > > 8085-based phone system weirdness continues and I'm beginning to wonder if > the PSU rails are all coming up in time for RESET to go high - given there's > 4116 DRAMs in there isn't there supposed to be a proper power up order? > > W

Re: 8085 RESET

On 2017-Mar-19, at 4:01 PM, Adrian Graham via cctalk wrote: > On 19/03/2017 19:59, bhilpert wrote: >> On 2017-Mar-18, at 5:21 PM, Adrian Graham via cctalk wrote: >>> >>> 8085-based phone system weirdness continues and I'm beginning to wonder if >>> the PSU rails are all coming up in time for RESET

Re: Looking for article: microprogrammed DIY TTL calculator

On 2017-Mar-20, at 6:58 AM, Jacek Greniger via cctalk wrote: > Hi, > > Two years ago I've found scans in PDF with the article (dated 197?, I don't > remember) describing DIY TTL-based calculator. This was microprogrammed > machine (if I remember correctly microproprogram was "stored" in the diode

Re: So what the heck did I just pick up?

On 2019-Aug-30, at 7:24 PM, John Ames via cctalk wrote: > Ran into this at the electronics-surplus store just down the way from > my workplace and grabbed it on the cheap. I don't actually know what > it *is,* but the labels on the switches make it look a *hell* of a lot > like a 16-bit general-pur

Re: Info on testing vintage power supplies

On 2019-Sep-02, at 9:35 AM, Alan Perry via cctech wrote: > Can anyone here provide a pointer to info on testing vintage power supplies? > Search results on the web may eventually lead to the kind of info that I am > looking for, but I have to get through too many pages of modern PC power > suppl

Re: Cleaning an old keyboard

On 2019-Sep-23, at 4:24 PM, Kevin Parker via cctalk wrote: > I resurrected an old keyboard and mouse I like. Not wishing to gross anyone > out but it looks like over time there was a build-up of oil etc from my > hands etc and over time being stored away its turned to a really almost hard > paste l

Re: HP vintage boards being sold as scrap

On 2019-Sep-25, at 3:07 AM, Guy Dunphy via cctalk wrote: > Does anyone else recognise some of the other boards? There is a stack of IO interface boards, including HSTs, for the HP 2100/1000 series there. Lower-right stack in this pic, 7 boards, boards have one red and one grey handle:

Re: fix? Repair? or leave alone? http://rcade.camden.rutgers.edu/2020symposium.html

On 2019-Sep-27, at 6:47 AM, Paul Koning via cctalk wrote: > I make it a habit to assume that every email which contains just a link but > no explanation is a scam with a forged sender address. > > Ed, if this is actually from you and actually real, and you want people to > look at it, you need t

Re: Mystery chip SCM44506L

On 2019-Oct-10, at 5:33 AM, Wouter de Waal via cctech wrote: >> Very likely a semi custom or custom memory device, due to the prefix. > > Armed with that and the fact that pin 1 connects to the leadframe I figured > maybe it's something like the 6830 Mikbug prom -- 0V on 1, 5V on 12, data on > t

Re: Restoring dull BOT markers?

On 2019-Oct-14, at 12:46 PM, Chuck Guzis via cctalk wrote: > On 10/14/19 12:26 PM, Al Kossow via cctalk wrote: >> >> On 10/14/19 9:32 AM, Daniel Seagraves via cctalk wrote: >>> What’s the best way to restore a dull BOT marker >> >> replace it >> >> there were rolls of brady BOT tape on ebay but

Re: Anyone familiar with these vintage touchscreens?

On 2019-Oct-20, at 9:14 AM, Nigel Johnson via cctalk wrote: > On 20/10/2019 06:43, Peter Corlett via cctalk wrote: >> On Sat, Oct 19, 2019 at 02:23:46PM -0400, Nigel Johnson via cctalk wrote: >>> Judging by the year, it was probably a teletext terminal. [...] >> It's not Teletext, unless that word

Re: Cheap minicomputer (Tracor-Northern 1610) on Facebook Markeplace (Allentown, PA) 18 bit?

On 2019-Nov-02, at 2:39 PM, Guy Dunphy via cctalk wrote: > A rack, a Tektronix XY display, > a rack drawer, blanking panels, some neat mysterious instruments, two 8" > floppy drives, > and a probable PDP-something all for $45? For what little it matters, the rack unit immediately below the CRT

Re: Question about modems

On 2019-Nov-13, at 5:22 PM, Electronics Plus via cctalk wrote: > ... I can simply connect 2 modems to each > other via a POTS phone cable, attach each modem via serial cable to a > different laptop, and set one to Listen and the other to Answer via > HyperTerminal. This will work for some modems,

Re: ge first transistors

On 2019-Nov-14, at 10:26 AM, dwight via cctalk wrote: > __ > From: cctalk on behalf of Chuck Guzis via > cctalk > Sent: Thursday, November 14, 2019 8:22 AM > To: dwight via cctalk > Subject: Re: ge first transistors > > On 11/14/19 8:05 AM, dwight via cctalk wrote:

Re: Question about modems

On 2019-Nov-14, at 6:48 PM, Jim Brain via cctalk wrote: > Well, I am off and running on getting my version of the code up to speed: > > https://github.com/go4retro/tcpser > > Man, some of this code is rough. I have learned a lot about writing C code > in the last decade+. > > Anyway, while I w

Re: Question about modems

On 2019-Nov-14, at 9:30 PM, Jim Brain via cctalk wrote: > On 11/14/2019 11:05 PM, Brent Hilpert via cctalk wrote: >> >> (Without having gone through the code presented in full detail, but thinking >> from root premises.) >> >> ASCII A = 0x41 --> 2 bits on &g

Re: Question about modems

On 2019-Nov-14, at 9:59 PM, Brent Hilpert via cctalk wrote: > On 2019-Nov-14, at 9:30 PM, Jim Brain via cctalk wrote: >> On 11/14/2019 11:05 PM, Brent Hilpert via cctalk wrote: >>> >>> (Without having gone through the code presented in full detail, but >

Re: Question about modems

On 2019-Nov-14, at 10:23 PM, Jim Brain via cctalk wrote: > If you look at the values received by an 8N1 connection from a sender using > the different settings, you get: > > AT > at > At > aT > 7E1 > E174 > 41D4 > E1D4 > 4174 > 7O1 > 61F4 >

Re: "First Internet message" and ...

On 2019-Nov-25, at 11:01 AM, Paul Koning via cctalk wrote: >> On Nov 25, 2019, at 1:45 PM, Richard Pope via cctalk >> wrote: >> On 11/25/2019 12:06 PM, Noel Chiappa via cctalk wrote: From: Fred Cisin Is that message about 1) history of internet? (THANK YOU for specifying "internet"

Re: Looking for a Motorola Universal Data Systems 212A/D manual

On 2019-Dec-16, at 10:35 AM, Michael Brutman via cctalk wrote: > I ran across this modem (circa 1982) and saved it, but I have no idea on > how to control it. Bitsavers doesn't seem to have a manual for it. > > It's a big, blue plastic box and it looks wonderful. There is an array of > 8 lights

Re: Sperry SP-425-08 Display - Datasheet?

On 2020-Jan-01, at 2:42 PM, Anders Nelson via cctalk wrote: > I snagged one of these Nixie-like displays (from a calculator I assume) and > I'd like to light it up. Does anyone know where I might find the datasheet > for it? Google hasn't turned up anything. > > https://www.ebay.com/itm/2641106389

OT post delivery / Re: Ordering parts onesie twos

On 2020-Jan-02, at 6:11 PM, Paul Berger via cctalk wrote: > On 2020-01-02 9:58 p.m., Nemo Nusquam via cctalk wrote: >> On 01/02/20 17:22, Ali wrote: >>> >>> >Well, Canada Post stopped delivering to individual >houses years ago. >>> >>> How does that work? >> Community mailboxes that serve a neigh

Re: Sperry SP-425-08 Display - Datasheet?

On 2020-Jan-01, at 6:14 PM, Anders Nelson via cctalk wrote: > I'd love to see examples of driving circuitry if it's not too much trouble. Remarkable that Tom found someone with spec sheets for the same type. Two examples of in-use are here (see the linked PDFs under tech data): http://ma

Re: Info / packs for Amcodyne 7110 "Arapahoe" drive?

On 2020-Jan-10, at 9:08 AM, Al Kossow via cctalk wrote: > On 1/10/20 5:18 AM, Chris Zach via cctalk wrote: >> Right off the bat it looks like a CDC Lark pack. Wonder if the whole thing >> is a re-badged Lark. > > There were three different companies that made 8" drives like that, Amcodyne, > Dat

Re: Interesting device on eBay -- CDC clock generator?

On 2020-Jan-17, at 12:11 AM, William Maddox on CCTalk via cctalk wrote: > The seller thinks this may be a drum memory, but it is clearly not. My > guess is that it is some kind of clock generator. Anyone recognize this? > > https://www.ebay.com/itm/Vintage-Mainframe-Computer-Part-Drum-Memor

Re: Interesting device on eBay -- CDC clock generator?

On 2020-Jan-17, at 4:04 AM, Guy Dunphy wrote: > At 02:22 AM 17/01/2020 -0800, you wrote: >> >> On 2020-Jan-17, at 12:11 AM, William Maddox on CCTalk via cctalk wrote: >> >>> The seller thinks this may be a drum memory, but it is clearly not. My >>> guess is that it is some kind of clock genera

Re: Mystery 1970 core board

On 2020-Mar-03, at 4:18 PM, Jules Richardson via cctalk wrote: > Hopefully collective wisdom can help on this one - does anyone have a clue > what system this core board was from: > http://www.classiccmp.org/acornia/tmp/coresmall.jpg > > The curved edge connectors (presumably to make board inser

Re: soviet resistor identification help and maybe lamps?

On 2020-Mar-07, at 11:10 PM, Adrian Stoness via cctalk wrote: > trying to identify these soviet resistors anyone familiar with how they > marked them i see 620 on these ones for the panel bulbs > https://www.flickr.com/photos/1ajs/49633358106/in/dateposted-public/ > > want to test all the lamps

Re: soviet resistor identification help and maybe lamps?

On 2020-Mar-07, at 11:35 PM, Adrian Stoness wrote: > yea i do but its not giving me anything thats making sens the value jumps all > over the place. on the ones ive tried If the Rs are high value, set the MM to the 2Mohm range and make sure your fingers are not touching the metal circuit elemen

Re: Vaxstation 400/90 power supply

On 2020-Mar-23, at 6:56 AM, emanuel stiebler via cctalk wrote: > I have 4000/90 which behaves funny. It only starts, after switching on > twice. The first time, all LEDs stay on, flipping the switch off/on, it > boots happily. > > Any insight? I've experienced behaviour like this in an Apple-som

Re: VAXmate PSU

On 2020-Apr-05, at 6:05 AM, Rob Jarratt via cctalk wrote: > I found time to follow Mattis’s suggestion today and I got some interesting > results. > > I powered the UC3842 with about 16V from a bench power supply. I lifted R32 > so that the transformer would not supply it. I then used an isolati

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