test-drb

test-drb@ccmp.vtda.org

101090 discussions

by jnc＠mercury.lcs.mit.edu

> From: Charles Dickman > So if the I/O page is completely (all processor modes) unmapped is > there any way to recover besides a power cycle? Does the RESET > instruction disable the MMU? Interesting questions! The CPU manuals don't say, about the RE$ET; I just tried it on the /23 I happen to have next to my desktop, and yes, the RESET instruction does clear bit 0 of SSR0. Noel

8 years, 5 months

VCF East keynotes -- holy moly!

by cctalk＠snarc.net

There will be three awesome keynotes for VCF East this spring. - Friday: our own Bill Dromgoole who'll talk about restoring the VCFed UNIVAC mainframe. - Saturday: Don Eyles (NASA contractor who hacked the Apollo Guidance Computer to save the Apollo 14 mission) - Sunday: Dave Walden, who programmed the IMP at BBN for the ARPANET

8 years, 5 months

PDP11 I/O page memory map

by dj.taylor4＠comcast.net

Is there a document that describes the bank 7 memory page and what addresses are reserved for what?? I think I've seen this before but can't seem to put my hands on it. Another question, bootstrap is reserved for 173000, how many words are allowed there for this?? How do the more complicated bootstraps, e.g. microPDP11-53, accommodate this limitation? Doug

8 years, 5 months

OT: Any tech apprenticeship opportunities in Brisbane, QLD?

by sellam.ismail＠gmail.com

Hello Folks. Forgive me for the intrusion. I know a good soul in Brisbane area in Queensland, Australia who is looking for some sort of apprenticeship in electronics or communications/networking. I thought I would ask here in case this message reaches some of you blokes down there that might be able to point him in a useful direction. He's in his 30s, very sharp and capable, gainfully employed in an entirely unrelated field and looking for a change in his life. Offline responses welcomed. Thanks! Sellam

8 years, 5 months

Vtserver 32MB limit

by bob＠theadamsons.co.uk

>From Dennis Boone > Jonathan Engdahl's homepage shows his email > address. His changes are explained at the page you linked. Yes indeed - as I (meant to have) said, no reply to his email listed there. > The 32MB limit arises due to the use of 16 bit block number fields in > the protocol. I understand the issue but alas I'm a mere hardware guy with minimal software skills so I was looking for a giant to carry me ;). > if it's useful, you can find it here: > http://yagi.h-net.msu.edu/vtserver.drb.tar Perfect - minor mod for my raspberry pi and it works just fine thanks. Bob

8 years, 5 months

PDP11 I/O page memory map

by jnc＠mercury.lcs.mit.edu

> From: Douglas Taylor > Is there a document that describes the bank 7 memory page and what > addresses are reserved for what? Here's one I collated from a large number of DEC manuals: http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/UNIBUS_Registers.txt (Ignore the name, it applies to QBUS machines too.) > bootstrap is reserved for 173000, how many words are allowed there for > this? Well, the space from 773000-773776 (UNIBUS and Q18 - add '17' to the front for Q22) is used for ROMs, and is the most common; 173000 is of course the location QBUS processors can be configured to jump to on power on. 765000-776 in also used for some (e.g. M9301's). > How do the more complicated bootstraps, e.g. microPDP11-53, accommodate > this limitation? Bank switching; e.g. the BDV11, KDF11-B have a 'page control register' at 777520 which says which block of ROM is mapped into the 773000 block. Interestingly, the DEC standard ROMs for the BDV11 and KDF11-B _don't_ copy all the contents down to real memory, and run from there - the code is divided into 'pages', only one of which is mapped in at a time, and it's executed from the ROM. Noel

8 years, 5 months

PDP11 I/O page memory map

by jnc＠mercury.lcs.mit.edu

> On many of the PDP-11s that page is signified by asserting BBS7 QBUS machines only; the UNIBUS has no equivalent signal. > FYI the microPDP-11/53 is the 11/23+ cpu card Err, no; according to the "MicroPDP11/53 System Supplement Manual" (AZ-GPTAA-MC), pg. 3-1, the CPU card in the /53 is the KDJ11-D. The /23+ uses the KDF11-B CPU card. Noel

8 years, 5 months

Suggestions for 16 mm movies to digital conversion

by jfoust＠threedee.com

At 01:09 PM 2/24/2018, Pete Lancashire via cctalk wrote: >I have a small, 5-20 stack of 16 mm's of movies dealing with computers >The one in front of me is >"Once Upon a Punched Card" >I am looking for a place in the USA with a reasonable price to have them >digitized and I will place them on both my Google drive and a Youtube >So far I have only been able to find places I can not afford. I use https://gomemorable.com/ . I've used them for both 8mm and 16mm. They have sales now and then that'll drop 40% off the price. They're running one now until March 3. They scan digitally with LED illumination, frame by frame. It'll brighten your old film in ways you can't imagine. They'll scan to HD (1920x1080) resolution. I send them a hard drive and they return the files as Quicktime ProRes movie files. These days, send 'em a bare SATA SSD to save on shipping. If you didn't want to edit yourself, they can send you a DVD or far better yet a Blu-ray. As I look at their web site now, I don't see a link that gets me to these services I describe, that I've used as recently as a month or two ago. I'll write them a note to see where the straight-forward per-foot pricing and hard drive options went. For 8mm, many old cameras would actually expose more of the width of the film than you'd ever see on your projector, so I have them scan the full frame. Here's an example of a color home movie from the 1940s that I had converted to VHS in the early 90s via telecine, compared to a modern digital scan: https://www.youtube.com/watch?v=f08K0Co3l5s - John

8 years, 5 months

More pictures of the 360/50 front panel

by pete＠petelancashire.com

https://photos.app.goo.gl/36CxlZQJDssj5uLh1 I will be pulling it out later this week and have more including the back and the hinged frame -pete

8 years, 5 months

Vtserver 32MB limit

by bob＠theadamsons.co.uk

I've been using vtserver to transfer an OS to a minimal pdp11 (only a HD and console port so far). Works fine but it has a well-documented 32MB file limit. This website http://home.windstream.net/engdahl/vtserver.htm mentions some hacks but I've been unable to contact the author. Anyone have details of either the code or author? Thanks Bob Sent from my iPad

8 years, 5 months

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