test-drb June 2007

test-drb@ccmp.vtda.org

224 participants
486 discussions

NorthStar Horizon Case Cover Replacements

by RodSmallwood＠mail.ediconsulting.co.uk

Hi Even though my main collection is DEC I'd love a Horizon with or with out its wooden case. I wrote a lot of code on one in CBASIC back in the 70's They are somewhat rare in the UK to say the least. In fact, the case is less of a problem than finding a system in the UK. I have a retired friend with fully equipped wood working shop. Consulting my 1979 copies of Practical Computing (a UK magazine). They were widely available in the UK. They must be out there somewhere. Rod Smallwood -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Allison Sent: 19 June 2007 12:37 To: cctech at classiccmp.org Subject: Re: NorthStar Horizon Case Cover Replacements > >Subject: NorthStar Horizon Case Cover Replacements > From: "Andrew Lynch" <lynchaj at yahoo.com> > Date: Mon, 18 Jun 2007 17:35:13 -0400 > To: <cctech at classiccmp.org> > >Hi, > > > >I noticed in another cctech mailing list thread about the NorthStar >Horizon case cover replacements. Recently, I procured a NorthStar >Horizon which is missing its original wooden case cover and I was >looking to either buy an original replacement or make a new one. > >I did not get a lot of responses to my queries on other forums for a >replacement wooden case cover so I am considering fabricating my own. >Apparently, it is common for Horizons to have lost their wooden covers >over time for many reasons and others have done what I am considering. > >Has anyone built replacement NorthStar Horizon case covers before and >would be willing to build more? They do not look terribly >sophisticated to build provided you have access to a table saw and the >proper bits. I was planning on just copying the dimensions from >another Horizon wooden case cover I already have. > >If anyone has a spare NorthStar Horizon wooden case cover, has built >new ones, or knows how to build a replacement, I would certainly like >to hear from you. Please email me or post here. > >Thank you in advance. > First it's a simple 3 sided thing. with a groove routed (or kerf cut) to overlap the cover. The corners are mitered, grooved for biscuts and glued. I added two 1/2" cleats to the corners of mine when I reglued it. There are 4 recessed hole for screws to secure it. Nominal material is 3/4 oak ply though current dimension materials would work as well. There is nothing special about it or difficulty in making it. The metal cover is simple but without a bending brake it's not easy to do. Allison

17 years, 6 months

FW: Open VMS Hobbyists Disc

by RodSmallwood＠mail.ediconsulting.co.uk

________________________________ From: Rod Smallwood Sent: 20 June 2007 01:55 To: 'cctech-bounces at classiccmp.org' Subject: Open VMS Hobbyists Disc Hi The above disk having arrived (new version 7.3) I managed to install VMS on both VAXes with out any problem. In order to install the other items first the disk has to be mounted. Again no difficulties. I can list the directories and see their contents. @SYS$UPDATE:VMSINSTAL invokes the installer, again normal. It then asks I'm satisified withthe backup of the system disk (Default [YES]) Next it wants the location of the distribution so I say DKA100:[TCPIP_VAX051] Finally it needs the product code. So TCPIP051 to that (they specify the format) It then says it cant find the product. Answers please! Rod Smallwood The DECCollector

17 years, 6 months

DEC M220 as a board-level bit-slice device (was Re: Inside old games machines)

by ethan.dicks＠gmail.com

On 6/19/07, Brent Hilpert <hilpert at cs.ubc.ca> wrote: > Before bit-slice chips, the HP 2116 was constructed in 'bit-slice form' from > SSI: 4 boards plugged into the backplane are identical, each board containing > 4 bits of the 16-bit ALU and main registers. I expect other SSI-era minis were > done this way. The PDP-8/L and PDP-8/i used this technique - six identical M220 "major registers" boards provided 2 bits each of the AC, PC, MA, and MB registers and the adders. http://www.bitsavers.org/pdf/dec/modules/mSeries/M220.pdf >From a glance at the schematics, it's about 30-some-odd inputs (various enables and adder/shift signals) and almost as many outputs on a dual-height card (72 pins total, including 2 Vcc and 4 GND). Looking at how the logic breaks down, perhaps it might be reimplementable with a pair of 22V10s for the lower part of the flow (combining enables and register bits into the adders), then perhaps a pair of 16V8s for the middle part (shifts and adds), then piped out to, perhaps, one 22V10 and then, if required for fanout, a quad buffer of some type to take the place of the two 7440s - six more modern parts to replace a stack of 7474s, 7483s, 7460s and 7440s and a 7482, of which, I think, only the 7474s are easy to find anymore. I only bring up the M220 at this level because I have a few dead M220s and will need to resort to component level repair or board-level replacement to keep my -8/i and -8/Ls running. From my existing experience, though, I'd start by ensuring my 7474s and 7440s are working as expected - I've replaced several in other boards over the years. They seem to be the two most common ICs to fail in my PDP-8/L. -ethan

17 years, 6 months

Anyone got a working DEC10 (or a running emulator?)

by gtoal＠gtoal.com

A friend at Edinburgh recovered some binaries, a bit of source code, and a fair bit of documentation for the Imp language running on the Dec 10. We're holding a reunion and historical conference in Edinburgh in a couple of weeks - it occurred to me it might be fun if I could show the folks back home that the old code was running again... Does anyone have a working Dec10, whether a physical or a virtual one? Our recovered code is here: http://history.dcs.ed.ac.uk/archive/dec10/imp/ (also if you pop up a directory there's some more stuff, but not of as immediate interest as getting the compiler to run again!) If you could download any of these binaries and give them a try I'ld be very interested to see the results. I think this ran under tops10/tops20 and the precise version of CPU shouldn't be critical I don't think. A trivial "hello world" imp program might be: %begin print string("Hello world!") newline %end %of %program If anyone can get it running, I'll announce it and credit you at the conference :-) Graham

17 years, 6 months

OT: demagnetization

by dgriffi＠cs.csubak.edu

Can someone point me to schematics for a decent homebrewed demagnetizer? I've accidentally magnetized a bunch of little parts that really shouldn't have been. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

17 years, 6 months

Wanted: Apple ADB keyboard

by zmerch-cctalk＠30below.com

Rumor has it that Richard may have mentioned these words: >In article <9e2403920706171739y297fe37dj6cbe2a1db48b675b at mail.gmail.com>, > "Josef Chessor" <josefcub at gmail.com> writes: > > > On 6/17/07, Richard <legalize at xmission.com> wrote: > > > Based on this, I believe I have a ROM 01 motherboard. It has a memory > > > expansion card in it that appears fully populated. Does it display > > > the amount of memory visible on startup? > > > > Unfortunately, no. You've got to have an Apple ADB keyboard to see > > that (enter the NVRAM setup screens by hitting Ctrl-OpenApple-Escape, > > and select the 'RAM Disk' to do so). > >Anyone got an Apple ADB keyboard laying around they'd like to offload? I believe I do - I'd have to check the attic, tho, to be sure. Dunno if it comes with a cable - would an S-Video cable work? Let me know if you want me to dig it out. Just pay shipping. Laterz, Roger "Merch" Merchberger -- Roger "Merch" Merchberger -- SysAdmin, Iceberg Computers zmerch at 30below.com Hi! I am a .signature virus. Copy me into your .signature to join in!

17 years, 6 months

Atari 800XL and 1050 disk drive in Delray Beach, FL

by darin.lory＠gmail.com

NNNNNOOOO!!!! UGH!!! My heart!! SHE THREW AWAY AN ATARI COMPUTER!! Dang! I would have gave her cash money for that!! That's almost as bad as when I came home from college and my Dad THREW out all my COMPUTE! magazines that I had saved up and were in MINT condition. -Darin He hoped and prayed that there wasn't an afterlife. Then he realized there was a contradiction involved here and merely hoped that there wasn't an afterlife. - Douglas Adams

17 years, 6 months

Finally fixed it! (was: Re: Complete success, OS/8 is up and running :) not so fast...)

by charlesmorris＠hughes.net

After intensive head scratching and hair pulling (accompanied by appropriate curses and a bit of scope and logic analyzer work ;) I finally found the problem with my 8/A this afternoon. First, of course, it was necessary for me to learn exactly how an M8315 CPU card works! The 7483 adder I suspected was not at fault since the logic analyzer always showed the correct outputs vs. inputs. I finally figured out that if the AC incremented properly, which it did, and was not data pattern sensitive, which it was not, that that ruled out almost all of the register circuitry except for a few gates unique to the MA (address) lines. For the curious, it was a bad 74367 (8097) hex buffer chip at E104 - actually only one section was bad, pins 14 -> 13 (which drives the ADD IN 4 line). Although both output enables were sitting low, every output matched its respective input except one... Even though the bit 4 line was a logic 1 (0 volts on that internal bus), the output was stuck at +5V (logic 0), explaining why on the next CPMA load that bit would always clear itself. Eureka... There was no hard short found, and connecting that line through a milliammeter to ground confirmed that only 5 ma would bring it to below .1 volts, so that current was mostly due to the 1K pullup resistor. The inevitable conclusion was that the output of that 74367 section was not able to pull low at all. I managed to change the chip without destroying the board too much and now all addresses increment properly again. Simple TTY print and keyboard echo programs work too :) Incidentally, I have pretty much given up trying to make a workable image with more than one 2 Mb partition on my RL02 drive. Every attempt to build one and boot it either hangs SIMH entirely, or worse yet, causes it to halt simulation with an error message, for some reason that's beyond my understanding. What the heck, 2 Mb is more than enough just to play around with OS/8 and run text adventure games anyway. If anyone can figure this out, I can email you a copy of my (currently working) image for reBUILDing. Of course the system now still won't boot (I can hear the drive head move, and then the RL02 FAULT light comes on) but it's likely the OS/8 image got clobbered when the chip failed and the CPU started writing to odd places. You can't write-protect the pack either, since OS/8 swaps in and out frequently to maintain such a tiny "footprint" in core. Anyhow I'm leaving tonight for three weeks of vacation in sunny Crete so it can just wait until I get home! -Charles >Naturally, I jinxed it by bragging about my success :( > >The next day, the system wouldn't boot and I could see the FAULT >light flicker as the system halted at address 10107. I initially >thought disk drive problems again, or the pack got clobbered >during swap-out for some reason. > >However, a little investigating quickly showed that even the most >basic ten-word TTY check program would not deposit or run. In >fact, when depositing or examining sequential locations I found >the address display would increment from 0200 to 0001. 0577 would >increment to 0400, etc. So something is wrong with address bit 4. >I pulled all the boards from the backplane except the CPU set and >it still does it. Now I've got to fix the hardware! Sigh. > >Meanwhile I have been SIMH-building a new OS/8 image from scratch >for two drives. After much struggle I have the RL20 handler >installed (which has logical drives R20A,B,C,D; the RL21 handler >with R21A-D, and I had to omit the last 20% (the "E" drives on >RL2E) because OS/8 can only allow fifteen handlers and space is >needed for (at least) the R2SY system handler, TTY, SYS and DSK >also... reminds me of Gates' "640K should be enough for anyone". > >-Charles

17 years, 6 months

Trouble with HP 59309A Digital Clock

by PWalsh＠energysolutions.com

Do you know where I can get a manual for this clock? Just started using one and need the technical data and operating instructions. I can scan into a PDF if need be. Thanks Pat

17 years, 6 months

Trouble with HP 59309A Digital Clock

by PWalsh＠energysolutions.com

Joe, Do you know where I can get a manual for this clock? I can scan one into PDF if need be. Just got one of these for a desk clock and need to know how to set the calendar addressed setting. Many thanks, Pat

17 years, 6 months

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test-drb June 2007