test-drb

test-drb@ccmp.vtda.org

101090 discussions

by bygg＠cafax.se

> Did the original KA10 have XCT too? XCT is present in all PDP-10 processors. From the KI10 and onwards it includes PXCT, since these have the concept of a previous context... Given a pager for the KA10 PXCT would make sense there. > Noel --Johnny

8 years, 4 months

PDP-6s at MIT

by jnc＠mercury.lcs.mit.edu

> From: Lars Brinkhoff > Does anyone know more about this PDP-6? Did it ever run ITS, like its > PDP-10 successor? I don't know about the software run on the two PDP-6's - by the time I arrived at MIT, they were both powered off and never, as far as I know, ever ran again. I would _assume_ that it ran ITS. I don't recall if the physical remains stayed until the KA's were de-commissioned, or of they were removed prior to that - I suspect they stayed, since they were mixed in with the KA's - in the case of AI at least, wired in together - but don't remember exactly. I don't recall if the I/O bus was shared between the two CPUs on the DM machines, the way it was on the AI KA and PDP-6. The DM PDP-6 was part of the DM KA 'assembly' - DM was in two rows (front and back) to the right of the right-hand door from the lobby into the machine room. IIRC, the PDP-6 was in the front row, to the right? of the KA CPU. (The back row contained memory boxes - a mix of different DEC memories. I don't recall where the tape and disk controllers were - or the disk drives. I seem to vaguely recall a few boxes to the left of the KA CPU? Maybe there are some pictures of the MAC machine room that will show it.) Noel

8 years, 4 months

by witchy＠binarydinosaurs.co.uk

Hi folks, I have an 8085-based viewdata telephone system on the bench that's proving to be a labour of love in trying to get it running with zero documentation - there are only 6 known examples that I've come across and all but 2 of them are in museums, none known to work. If any of you fancy searching it's an STC Executel 3910 and at least two of the hits you'll get will be my machine before I bought it. http://www.binarydinosaurs.co.uk/stcexecutel01.jpg I've been in contact with all museums who have one, no luck on docs though the Museum of Computing which is local to me MAY have some (Jason the owner has 2 3910s himself), I just need to get down there and search for it :) Kind-of-fortunately the viewdata side of things seems standard - all 74LS TTL with an MC3242AP running 16x 4116-2 DRAMs, 27128 EEPROMs etc. The viewdata side of things is powered by a Plessey MR9735-002 teletext processor supported by a pair of 2112 RAM chips and an SAA5070 "LUCY". http://txlib.mb21.co.uk/main.php?g2_view=core.DownloadItem&g2_itemId=2034 ROM selection is done by a PAL but my EEPROM reader has verified that's OK and I have a dump of it as well as all the ROMs. Unfortunately it's suffered battery leakage and it was seemingly stored on its back in a very damp environment so some of the capacitors at the rear of the board have rotted and bits of the analogue board for the 5" TV had rusted to nothing, though I've replaced those. What I originally thought was an analogue board issue that I posted about here has turned into a total lack of timing issue so I've been tracing out all the circuits and building a schematic of the board. All was well until I came to the two chips you can see in the centre of this pic that have no markings (9B and 10B on the board): http://www.binarydinosaurs.co.uk/stcexecuteltimingcircuits.jpg They aren't 'standard' 14-pin DIPs in that they don't follow the GND-on-pin-7-Vcc-on-pin-14 layout. Pins 6 and 7 on both are wired together (not to GND) and form the RESET signal for the 8085 via the 7414 at 10A, source for this signal is unknown currently. Pin 5 on both appears to be Vcc and pin 10 is GND or at least are pulled high and low respectively. The XTAL you can see with its supporting resistors is connected to the 7404 at 12B, pin 12 of which goes to pin 1 of 10B (one of the mystery chips) and pin 1 (X1) of the 8085. Any clues? I'm going to search for reference 8085 boards (and I guess 8086?) layouts to see if there are any similarities in timing circuits but for now I'm stumped. Cheers! -- Adrian/Witchy Binary Dinosaurs creator/curator Www.binarydinosaurs.co.uk - the UK's biggest private home computer collection?

8 years, 4 months

Motorola MC14081B

by witchy＠binarydinosaurs.co.uk

Evening folks, (it's evening here) Typically for troubleshooting around $FESTIVAL I find a more-than-likely dead MC14081B (CMOS quad dual-input AND gates) just as UK postage ends for the next few days so getting a replacement won't happen until next week. Question is, aside from having to make up an adapter board to change the pins around and making sure Vcc is +5V is there any reason I can't use something like a 74LS08 for testing? One of the outputs is RESET for an 8085A so nothing too demanding. (I might have a CD4081B somewhere too, which is pin compatible according to the datasheet) Cheers, -- Adrian/Witchy Binary Dinosaurs creator/curator Www.binarydinosaurs.co.uk - the UK's biggest private home computer collection?

8 years, 4 months

Late 90s Macintosh systems available to So Cal

by tosteve＠yahoo.com

I have a small pile of late 90s Macintosh systems available for someone to pick-up in 92656. Performa 6400/100 tower Some PowerBooks - 3400, 5300, 7630 Also boxes of cables and software. LaserWriter 4/600P Makes a great Christmas present! Thanks- Steve.

8 years, 4 months

Wanted Dead or Alive: Tadpole N40

by ian.finder＠gmail.com

Been having a baaaad month for hardware longevity. Lots of systems have died in 2016... A miserable year. Just took my only two Tadpole N40s out of cold storage and both are having some serious issues, stopping at 260 post code, no video, no status LCD, etc. If I had one more system, I'm sure I could get one running. If you have an N40 for sale, or that you'd consider selling, please ping me. I'd love to pay you for it :) Thanks, - Ian -- Ian Finder (206) 395-MIPS ian.finder at gmail.com

8 years, 4 months

Altair 680 Expansion Boards?

by spereira1952＠comcast.net

Hello folks, I was (finally) lucky enough to acquire an Altair 680 back in November, and I have been able to get it back up and running, too. Now that I have a fully working stock Altair 680, I am interested in acquiring expansion boards for it. If anyone has any Altair 680 expansion boards, especially a memory expansion board, that they are willing to part with, please let me know. Thanks for listening. smp -- Stephen M. Pereira Bedford, NH 03110 KB1SXE

8 years, 4 months

Bounty: Motorola Tango

by cctalk＠snarc.net

Anyone have a Motorola Tango? It's a two-way pager from 1995. If you have one, then contact me privately. Can't discuss this on the list.

8 years, 4 months

Felton, CA: Free kit - compact macs, //e, //c, etc

by salgernon＠me.com

So, I need to debulk my collection. A few years ago I took about 1/3 this much to the Foothill (now DeAnza, I guess) fleamarket and came away with $2k, which almost covered the cost of the storage locker it had been in! What you do with it would be up to you. I've got about 15? 2x2x3 ish plastic totes full of cables, floppies, development tools (pascal, tmon) and there's an apple //e, several //c, se/30, classic, hard drives. LocalTalk connectors. All fairly clean and non-smoking. I think there's a mac rom emulator, an Apple // CFFA card, probably a puppy or two. Must take it all! It's probably two pickups worth or one uhaul. My place is in downtown Felton, should be easy to park and load up although I'm physically limited in what I can do to help. Shipping is not an option unless you arrange a crating / hauling company. Please reply off list for best results. Cheers, --sma

8 years, 4 months

PDP-6s at MIT

by jnc＠mercury.lcs.mit.edu

> I suppose it's likely they both used the same master/slave > configuration. However, there's one thing I found that may indicate > that the DM machine went in an other direction. I think the latter may be true, I have this vague sense that the two DM machines were never interonnected the way the AI pair were. For one, the DM people didn't have a bunch of oddball hardware connected to their main machine, the way the AI people did. (There was a special Evans+ Sutherland display processor, but that's about it. The ITS sources will probably have a complete list, until the DM configuration section.) They also didn't have as deep a bench of hardware people. Also, I remember reading somewhere (it was decades ago, sorry, don't remember the source) that AI's paging box was subtly different from the one on DM; the AI one could IIRC, address 4 'moby's (a full PDP-10 address spare), and two (I think? I'm pretty sure all the KA's had two moby's of main memory) were used for the Fabritek 2-moby memory, one was for the PDP-6 (so the KA could see into it) and one was for the PDP-11's. (AI had a number of PDP-11's attached to it - one to drive the Xerox Graphic Printer, one to drive the Knight TV system, and I think maybe one more, the so-called I/O -11 - or was that on MC, which had two -11's - the standard KL front console -11, and I think one more? I'm can't quite remember, although I'm pretty sure neither DM or ML had any -11's. Anyway, on AI, the KA could see into the memory of its PDP-11's. If you look at the ITS sources this probably is all laid out there.) So probably the DM -6 and -10 were two separate machines. > MX kl10 (expand ML group to high performance) Actually, this machine was named MC when it first arrived, and kept that name until its 'replacement', a KS, arrived, _many_ years later. (They didn't want to give the new machine a new name, since there were a ton of mailing lists on 'MC', and it was easier to swap the machine names.) It was renamed 'MX' at that point. It was called 'MC' since it was bought for the Macsyma Consortium (part of LCS, not sure if it was part of the ML group, it might have been). Noel

8 years, 4 months

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