-----Urspr?ngliche Nachricht----- Von: cctalk [mailto:cctalk-bounces at classiccmp.org] Im Auftrag von cctalk- request at classiccmp.org Gesendet: Mittwoch, 7. Dezember 2016 19:00 An: cctalk at classiccmp.org Betreff: cctalk Digest, Vol 30, Issue 7 Send cctalk mailing list submissions to cctalk at classiccmp.org To subscribe or unsubscribe via the World Wide Web, visit http://www.classiccmp.org/mailman/listinfo/cctalk or, via email, send a message with subject or body 'help' to cctalk-request at classiccmp.org You can reach the person managing the list at cctalk-owner at classiccmp.org When replying, please edit your Subject line so it is more specific than "Re: Contents of cctalk digest..." Today's Topics: 1. Re: Double Buffer RK11-C (Fritz Mueller) 2. Re: UNIBUS/QBUS interface chips Was: Re: MEM11 update (allison) 3. Re: Intel C1101A (allison) 4. Re: Double Buffer RK11-C (Paul Koning) 5. Could somebody please help me identify this board? (Chris Pye) 6. Re: Could somebody please help me identify this board? (Jon Elson) 7. Re: Could somebody please help me identify this board? (Chris Pye) 8. Miniscribe 6053 HD PCB needed (Mike Stein) 9. Re: Could somebody please help me identify this board? (Mike van Bokhoven) 10. Re: Could somebody please help me identify this board? (Eric Smith) 11. Have lunch with Lee Felsenstein (Evan Koblentz) 12. Wanted: Terminator for an RL02 (Tom Moss) ---------------------------------------------------------------------- Message: 1 Date: Tue, 6 Dec 2016 11:56:38 -0800 From: Fritz Mueller <fritzm at fritzm.org> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Double Buffer RK11-C Message-ID: <DF227289-9352-4646-8339-72E2640AF202 at fritzm.org> Content-Type: text/plain; charset=utf-8 > On Dec 6, 2016, at 7:51 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu>

> > [data fetch] can't be off-loaded onto a separate interface unit, as it

access to Yeah, it?s pretty interesting! My guess would be that it was a separate register/command oriented interface, sitting on the Unibus, and didn?t

interface directly with the 11/20 CPU? Such an interface could limit the instructions ?fed? to the FPU to those accessing its internal registers,

who knows? :-) I?ve gotten quite deep into the design of the FP11-B and associated KB11-A interfacing during my debug (which is how I noticed all the 11/20 refs in

docs, circuitry, and microcode), but I?m pretty ignorant of the 11/20

never worked on one. > I wouldn't be surprised if there's some microcode in the KB11 to support

memory operations. Yes, there certainly is ? quite a bit of it actually. The are F/CLASS

three of the A, B, and C forks. ?FritzM. ------------------------------ Message: 2 Date: Tue, 06 Dec 2016 14:24:21 -0500 From: allison <ajp166 at verizon.net> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: UNIBUS/QBUS interface chips Was: Re: MEM11 update Message-ID: <8d451f35-e495-5feb-86b4-e0b0992ed2d7 at verizon.net> Content-Type: text/plain; charset=utf-8; format=flowed On 12/6/16 10:05 AM, Toby Thain wrote: > On 2016-12-06 1:34 AM, Eric Smith wrote: >> On Mon, Dec 5, 2016 at 6:53 PM, allison <ajp166 at verizon.net> wrote: >> >>> A bunch of us old digits (former dec engineers) got together and were >>> talking >>> about old systems and the thing that stood out is a general dislike

>>> having >>> to use the limited set of bus interface chips when there were newer >>> parts. It >>> was a internal mandate not something that was better than could be

I'm not a noob. I'm an engineer from the the realm of DEC engineering. I also forget the 74LS14 hex inverter with hysteresis which has a threshold about 1.5V depending on whos datasheet you believe. Bottom line is the older parts has a low Vih and a high Vil with a resulting narrow noise immunity. Increasing the Vih helps this and the driver/bus combo can support it. The yabut is if the drivers have leakage then attaining Vih on the bus is problematic as the leakage was a undesired pull down. The 8xxx parts used were screened for low leakage with output is in the high state (open as they are open collector). The bus loads assert the Voltage high state and that is above 2.3V so the only limiting factor then is excessive capacitive loading which smears pulsed by RC time constant. The other issue with slow edges is where the edge really is and that adds uncertainty to timing. All of those things were allowed for in the design of the bus. The voltage your hung up about was tested to insure it was never lower than that or the noise immunity was terrible. Its companion was was that the saturated device in the package could also achieve the limit or less or a low voltage at the rated current, at that time (late 60s early 70s) this was a hard parameter to control. The bottom lime is the better the logic high voltage and logic low voltages achieved the greater noise immunity. Adding hysteresis insure that a hig is high and a low is low and not some random analog voltage inbetween (or oscillation!). As to any slew rate testing the issue was that devices that could sink the needed current were also slow as sludge and had to be tested to insure they were fast enough not that they would have a slow propagation time and switching speed as that was also a undesired in systems where fast is important. Bottom line is the datasheet and purchase spec was to insure the part worked to or better than expected rather than implying magical properties. Allison > I'm referring to this part of October's thread: > http://www.classiccmp.org/pipermail/cctalk/2016-October/028871.html > > > --Toby > > >> important for large systems with multiple bus segments. That was >> particularly important for large Unibus systems, but even Qbus with

>> two bus segments can get finicky when heavily loaded. >> >> DEC could easily have made custom interface ICs if they had needed

------------------------------ Message: 3 Date: Tue, 06 Dec 2016 14:27:22 -0500 From: allison <ajp166 at verizon.net> To: "General Discussion: On-Topic Posts" <cctech at classiccmp.org> Subject: Re: Intel C1101A Message-ID: <33d486b9-62b2-a536-82d5-c9b61c41c71e at verizon.net> Content-Type: text/plain; charset=utf-8; format=flowed On 12/6/16 11:46 AM, Brad H wrote: > I kind of thought that might be a possibility. I might just let things

while.. I was concerned about stock disappearing, didn't think about price tripling. Not sure I want to spend $1400 for 1K of RAM on a clone. :) Cohen <cctalk at classiccmp.org> > Subject: Re: Intel C1101A > > I do notice these "schlock" IC sellers actually raise the price the more

they get on an item. So your shopping around will actually make the price

and my even cause your earlier vendors to raise their price when you

place an order. > > corey cohen > u??o? ???o? > >> On Dec 4, 2016, at 9:00 PM, jim stephens <jwsmail at jwsss.com> wrote: >> >> >> >>> On 12/4/2016 3:29 PM, Brad H wrote: >>> The supplier (a different one from the one I first used) that quoted >>> me on C1101A for the second round sent me a picture.. exact same 'lot'

'job' >>> number as the ones I have. So perhaps even that may not be

>>> What are the odds I'd hit the exact same dates from two different

>>> >>> I'm thinking it's*fairly* safe to assume white ceramic is pre-76, at >>> least.. but yeah.. might be impossible to ever really know. I'm just >>> wondering why the price jumped to $40+ each all of a sudden! >> Brad, >> a very large number of schlock IC sellers all communicate with each

They all have a continuous stream of wants or needs that they exchange.

they make their own prices. The probability is that you may have hit the

stocking guy with your first query. Querying any others will result in

looking at the wants that others shared, or buys, and he saw someone else

it and quoted you the same info. >> >> I know this happens as I know two guys who trade in all manner of stock

the time like this and have for 35 to 40 years. Considering the first 1101s I ever bought in the early 70s were around 12-14$ each in small volumes (24-48). By the mid 1975s they had dropped to a buck or so as there were faster and denser parts. But then the first 2102s cost me about 14$ in early 74 so that was the way it was. Allison ------------------------------ Message: 4 Date: Tue, 6 Dec 2016 16:13:43 -0500 From: Paul Koning <paulkoning at comcast.net> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Double Buffer RK11-C Message-ID: <E3C0D8A7-1B50-4877-97E1-7E930FDD07A7 at comcast.net> Content-Type: text/plain; charset=utf-8 > On Dec 6, 2016, at 2:56 PM, Fritz Mueller <fritzm at fritzm.org> wrote: > > >> On Dec 6, 2016, at 7:51 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu>

>> >> [data fetch] can't be off-loaded onto a separate interface unit, as it

access to register/command oriented interface, sitting on the Unibus, and didn?t

interface directly with the 11/20 CPU? Such an interface could limit the instructions ?fed? to the FPU to those accessing its internal registers,

who knows? :-) I don't know anything of a DEC product along those lines, but a college classmate of mine (Bill Black, Lawrence Univ. class of 1975) built a

coprocessor for our PDP11/20 that was a Unibus peripheral. I helped with

software interface. The device had 4 registers, two for source and two

second source and result. They appeared at several different bus

you'd select the operation to perform based on which address you used.

device would start when the 4 source words had been loaded, then a read

of the result register would simply be held off until the operation was

(since it would complete well within the SSYNC timeout). The implementation took, if I remember right, one hex-sized wire wrap

paul ------------------------------ Message: 5 Date: Wed, 7 Dec 2016 10:57:03 +1000 From: Chris Pye <pye at mactec.com.au> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Could somebody please help me identify this board? Message-ID: <BE8ACBED-16AE-4C35-B519-33E5DF0FFEF7 at mactec.com.au> Content-Type: text/plain; charset=utf-8 I?m moving my collection and found this board amongst some others. https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM <https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM> Cheers, Chris ------------------------------ Message: 6 Date: Tue, 06 Dec 2016 20:32:10 -0600 From: Jon Elson <jonelson126 at gmail.com> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Subject: Re: Could somebody please help me identify this board? Message-ID: <584774AA.2050400 at pico-systems.com> Content-Type: text/plain; charset=utf-8; format=flowed On 12/06/2016 06:57 PM, Chris Pye wrote: <https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM> It appears to be an extended-length Multibus II board with 2 8-bit DACs on it. Output for an XY scope? Jon ------------------------------ Message: 7 Date: Wed, 7 Dec 2016 12:40:49 +1000 From: Chris Pye <pye at mactec.com.au> To: elson at pico-systems.com, "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Could somebody please help me identify this board? Message-ID: <00BE5D7E-6202-4D62-851D-FAA884636B7A at mactec.com.au> Content-Type: text/plain; charset=utf-8 <https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM> >> >> Cheers, >> Chris > It appears to be an extended-length Multibus II board with 2 8-bit DACs

Output for an XY scope? Thanks Jon If anybody wants it, they can have it for cost of postage. I am in

Australia, so it?s probably going to be costly outside AU.. ------------------------------ Message: 8 Date: Tue, 6 Dec 2016 21:58:24 -0500 From: "Mike Stein" <mhs.stein at gmail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Miniscribe 6053 HD PCB needed Message-ID: <074CFFA13AFF454581BCC3E1EEEC5306 at 310e2> Content-Type: text/plain; charset="iso-8859-1" Hi all, I accidentally dropped something on a Miniscribe 6053 44MB HD and cracked the board; looks pretty dense and tricky to repair so I'm hoping that

kind soul out there somewhere who happens to have a 6053 doorstop and can spare the circuit board for a good cause? Removing the board shouldn't impair the door-stopping capability in any

Mike (in Toronto) ------------------------------ Message: 9 Date: Wed, 7 Dec 2016 18:18:36 +1300 From: Mike van Bokhoven <mike at fenz.net> To: cctalk at classiccmp.org Subject: Re: Could somebody please help me identify this board? Message-ID: <ed5f1e6c-2028-d7dc-88ea-5090430b2e8b at fenz.net> Content-Type: text/plain; charset=utf-8; format=flowed On 7/12/2016 1:57 p.m., Chris Pye wrote: <https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM> It's a Compugraphics board of some sort, I think. Couple of AD or DAs, etc. I know nothing about these, just recognised the logo. Cheers - Mike ------------------------------ Message: 10 Date: Tue, 6 Dec 2016 22:57:08 -0700 From: Eric Smith <spacewar at gmail.com> To: elson at pico-systems.com, "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Could somebody please help me identify this board? Message-ID: <CAFrGgTTLic5hnQRwpDjAc- syKRd13cpTtbU0ZC3d41dAFaw=hQ at mail.gmail.com> Content-Type: text/plain; charset=UTF-8 On Tue, Dec 6, 2016 at 7:32 PM, Jon Elson <jonelson126 at gmail.com> wrote: > It appears to be an extended-length Multibus II board with 2 8-bit DACs

Extended-length Multibus. Definitely not Multibus II, which uses Eurocard 6Ux220 form factor with two 96-pin DIN 41612 connectors. ------------------------------ Message: 11 Date: Wed, 7 Dec 2016 02:34:26 -0500 From: Evan Koblentz <cctalk at snarc.net> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Have lunch with Lee Felsenstein Message-ID: <42f12b6a-d3ab-8739-2d83-0f7f420145eb at snarc.net> Content-Type: text/plain; charset=utf-8; format=flowed Only 12 hours left to bid on lunch with legendary computer engineer Lee Felsenstein! This benefits Vintage Computer Federation, a 501(c)3 non-profit devoted to enabling collectors, growing the hobby, and spreading awareness of computer history. Please see https://www.charitybuzz.com/catalog_items/lunch-for-3-with-personal- computing-social-media-icon-1198500. ------------------------------ Message: 12 Date: Wed, 7 Dec 2016 16:10:16 +0000 From: Tom Moss <tomjmoss at googlemail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Wanted: Terminator for an RL02 Message-ID: <CAN69K+bG2C4xg5i7N_Vyc7gvGVYd7otHJwwqg2Rp4CytokhqfA at mail. gmail.com> Content-Type: text/plain; charset=UTF-8 Hi All, Does anyone have a spare RL02 terminator for sale? Regards, -Tom End of cctalk Digest, Vol 30, Issue 7 *************************************