test-drb

test-drb@ccmp.vtda.org

101090 discussions

by jnc＠mercury.lcs.mit.edu

> From: Mattis Lind > What about the M9300 board? Do you have an idea what the purpose is of > that card? Yes, that one's well-documented and understood. It's intended for use on the 'B' UNIBUS of the RH11-AB, in deployment configuratons where that UNIBUS is in use, but there's no CPU on it to respond to NPR bus requests. (See: http://www.bitsavers.org/pdf/dec/unibus/RH11_Peripheral_Controller_Course.p… pg. 11 for an example; the 'B' UNIBUS of the -11/45 is used for a separate path into the 45's dual-port FASTBUS memory.) On such a UNIBUS, the M9300 is used at the start of the bus, and is jumpered to allow on-board circuitry to respond to an NPR with an NPG.It also has a SACK timeout capability, documented in: http://www.bitsavers.org/pdf/dec/unibus/RH11-AB_OptionDescr.pdf on pp. 69-70, but I'm not fully familiar with that. Noel

3 years, 12 months

Is The M9312 Boot Module Essential?

by jnc＠mercury.lcs.mit.edu

>> On Feb 19, 2022, at 10:51 AM, Noel Chiappa wrote: >> The -11/34 (not the /34A) has something unusual for grant timeouts, >> but I forget the details. I'll look it up. And here it is... > From: Fritz Mueller > I think you are thinking of the M9302, Noel: a far-side terminator card > with integrated SACK turnaround? No; the M8264 Sack Timeout module. What's an M8264, you say? Well, there's next to nothing in print about them, but I think I've managed to assemble enough distant clues to work out their story. Start with EK-11034-OP-PRE2 (I have a hard-copy of it); it gives a clue as to how it all started. In 3.10.2, "End-of-Bus Terminator", it says: "As a result of this [SACK turnaround] circuitry [on the M9302], the SACK timeout feature found on other processors is not required" So if i) a device requests a grant, and then drops the request at _just_ the right time (so a grant gets sent out when there's no device waiting to grab it), and ii) there's a break in that grant line (maybe a missing grant continuity card) before it gets to the M9302, which can turn it around as a SACK , then ... the KD11-E CPU will hang! The M8264 was apparently the first attempt to deal with this. Like I said, there's next to nothing in print about them. EK-11034-UG-001, in Section 1.2, "System Description", does list "M8264 SACK Timeout module (11/34 only)" in the list of components - but says nothing else _at all_ about it! There is one page of circuit diagram of it, in: http://www.bitsavers.org/pdf/dec/pdp11/1134/MP00082_1134_Vol2_Sep76.pdf on pg. 149. The rest of the prints for it (e.g. the PCB layout) aren't there, but I happen to have one - it's a quad board with only a few components on it. Looking at the circuit diagram, it's mostly just a 9602 retriggerable, resettable one shot. (There's also a synchronous 4-bit up/down counter, but that's just there to count events, and display the count in some LEDs - probably just to make sure it isn't happening too often.) Since I'm not a real hardware type, I'm not absolutely certain just from looking at the circuit diagram exactly what it does, or how, but EK-KD1EA-MM-001 Section 4.7.2.4, "No-SACK Timeout Circuitry", shows a very similar circuit, and says it "asserts BUS SACK ... [if the device] does not assert SACK within 22 usec after a grant line has been enabled." Presumably the M8264 does the same thing. Interestingly, that circuit appears in the KD11-EA prints on pg. K2-10; the KD11-E prints have a blank space on that page where this circuit is in the KD11-EA prints. Since the M9302 appears in EK-11034-OP-PRE2, with SACK turnaround, I deduce that the M8264 was produced _after_ that came out, and post-dates the M9302, to fix the potential CPU hang issue I described - and was later dropped when the -11/34 switched to the KD11-EA, with that circuit built in. I'll do a page on the CHWiki about the M8264, and include an image of one. I figure I might use my M8264 on my -11/04, which also doesn't have SACK timeout (on the BG lines, for sure; it looks like it might have it on the NPG line). The M8264 doesn't tie into the CPU, it just looks at UNIBUS lines, so it can be plugged into any UNIBUS machine (near the start of the bus, since the grant lines it monitors are wired sequentially). Noel

3 years, 12 months

Information about an unknown IC

by clemarjr＠gmail.com

Hi I'm looking for information about Texas Instruments TB-759933 IC. Does anyone have the datasheet or any other information about this IC? Thanks.

4 years

Seeking paper tape punch

by fedorkow＠mit.edu

hi Steve, ? There's lots of raw material out there.? Al Kossow read hundreds of tapes a couple years ago, and posted the images at http://www.bitsavers.org/bits/MIT/whirlwind/X4222.2008_Whirlwind_ptp/ ? Whirlwind and modern readers disagree on what order the bits come in, but other than that, the files are perfectly usable.? We have some of the programs running in simulation, as you've seen. ? The Whirlwind tapes in the archive are all seven-level tapes punched on 7/8" paper. ? Let me know if there's something I can help with /guy Date: Tue, 22 Feb 2022 12:24:18 +1000 From:steven at malikoff.com To: "ben"<bfranchuk at jetnet.ab.ca>, "General Discussion: On-Topic and Off-Topic Posts"<cctalk at classiccmp.org> Subject: Re: Seeking paper tape punch Message-ID: <78ae9afacbca8b3ca7e7a41c677659d0.squirrel at webmail04.register.com> Content-Type: text/plain;charset=utf-8 Ben said > This requires a REAL MACHINE SHOP ... none this 3d printer stuff. I > would recommend a building a 35mm film punch and reader, as film stock > is still easy to find compared to paper tape. Zuse used them for his > computers in Germany on the 40's. Quality Mechanical stuff is lost high > tech. Consumer-grade CNC stencil cutters are fine at cutting plastic sheet and should be ok with film stock. My ptap2dxf (latest version 1.3) will produce output to cut tapes for 8-level ASCII, 5-level Baudot, 2-level Morse (Wheatstone and Cable Code), 7-level Whirlwind, Teletype Chadless and some customising options too. Still some other formats to do such as Colossus etc. Thanks for the notion of making Zuse tape, will look into it. Steve.

4 years

11/83 operating system load update -2

by rodsmallwood52＠btinternet.com

Hi ?? Well I have had a huge response to my request. I am unsure as to if I have defined the problem properly. So a few bullet points. 1. The objective is to copy RX50 disk images (*.dsk format) to genuine DEC RX50 disks. 2. The PC I want to use is a DEC Celeibris FX ie the PC and its W95 software is as supplied by DEC. 3. It has an RX33 5.25 inch floppy drive. 4. The RX33 _*is*_ capable of? reading and writing RX50 disks. 5.? putR was supposed to be able to do this. It does not. 6.? All that is lacking is the right utility. 7. Doing this does not need any disks other than RX50's. 8. Linux in any of its myriad of forms is not the answer. 9. simH is good at what it does but of no use here 10.? Its just a W95 utility program to copy an RX50 disk image to an RX50 disk on an RX33 drive on a DEC PC. 11. So whats it called? Does it work? given the above situation? Rod

4 years

11/83 OS load - problem solved.

by rodsmallwood52＠btinternet.com

Hi ???? Well I now have a full set of DEC orignal MicroRSX RX50 distribution disks. An old friend who I worked with at DEC had kept his install go bag and there they where. Not only that they are good and do boot. Its not over, RT-11 would be a better fit so I'm looking at that. Rod

4 years

DEC VT52 CRT anode connection

by fritzm＠fritzm.org

Hi folks, I?ve begun some work on a VT52, and need to get the power supply board out onto my bench for some work. For those who have been in here before: is there a way to detach the HV anode lead at the board side (does the white ?cap? come off the lead connector?) Or is the only option to unclip at the CRT itself? They don?t make it easy to get to the anode cap in this terminal ? one has to pull the whole tube, with the power supply board in tow. After doing this for an inspection, I find the anode cap looking little brittle and covered with some red, oily ?goop?? I?d rather just leave that alone and detach from the board side if it works that way? cheers, ?FritzM.

4 years

Speaking of tubes in computers.... 1st Honeywell 1000 computer used some surprise tubes!

by couryhouse＠aol.com

Speaking of? tubes in computers.... 1st Honeywell 1000 computer used some surprise tubes!? ??Imagine our surprise back then as? we unpacked our? first? group of? contributed Honeywell 1000 logic and saw....? LOCTAL TUBES!?Although SMECC does not? have? a complete Honeywell system of? this model? (CPU and? PS would? weigh in at 25,000 pounds? we have been told)? We DO possess? a wonderful collection? of documentation, parts? and? misc.? material related? to it, perhaps one of the best. Who else has some? We? used? to? think our 2 inch QUAD? videotape was a monster reel of? tape...BUT? WAIT!The First Honeywell Computer used 3 Inch Wide Tape! It was like mounting a Volkswagen Tire Wheel onto your computer tape drive! Channels or tracks on the tape... 31 Channels ?ALWAYS LOOKING? FOR MORE RELATED TO THIS COMPUTER!? See more info on this computer at: http://www.smecc.org/honeywell_datamatic_1000.htm drop me a note at? couryhouse at aol.com?

4 years

cctalk Digest, Vol 89, Issue 21

by athornton＠gmail.com

The 11/83 question sounds like a job for SCSI2SD to me. Install a system with simh. dd the resulting disk image to your sd card. Hook the SCSI2SD up to your 11/83 and boot from the card. Copy the contents of that drive to your real SCSI drive. Done. SCSI2SD cards are not expensive and are a tremendous value for money.

4 years

'dd' for Windoze (Was: cctalk Digest, Vol 89, Issue 21)

by jnc＠mercury.lcs.mit.edu

> From: Rod Smallwood > dd is a linux command. UNIX, actually. (V5, I think: https://minnie.tuhs.org/cgi-bin/utree.pl?file=V5/usr/source/s1/dd.c There no 'man'page for it in V4. Anyway...) > I only have windows PC's. There are Windoze versions. I've used this one: http://www.chrysocome.net/dd with success (under XP; probably works under others, too). Noel

4 years

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