test-drb

test-drb@ccmp.vtda.org

101090 discussions

by shawn-gordon＠cox.net

This was a screen driver I'd written to do pseudo windowing on green screen terminals. I thought it would have made more sense and been cleaner in C, but it wasn't. On 2/17/2015 9:27 PM, Mouse wrote: >> I've rewritten cobol into C a few times when I was a big enthusiast >> of C and the C code was longer and harder to maintain. >> > That is no surprise to me. If you were to take code written in C and > translate it into COBOL, I'd generally expect the COBOL code to be > longer and harder to maintain, too. > > Indeed, I'd expect that for pretty much any pair of languages; > translating code out of the idiom it was written for generally makes it > larger and harder to understand. > > /~\ The ASCII Mouse > \ / Ribbon Campaign > X Against HTML mouse at rodents-montreal.org > / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B > >

11 years, 5 months

PDP 11/40 AC LO and M7235 (Status K5 Module)

by billdeg＠buzz1.com

Working on PDP 11/40, issues with DC LO and AC LO The front panel confirms a DC LO issue, CONS and RUN lights are off, BUS and PROC lights are on. The panel is unresponsive. With the cable removed from the h742a connector, P9 says DC LO and AC LO are 3.53v, which is lower than the expected +4.8v. This tells me there is a fault in the h742a. I hate to remove the 742a power control board but I finally have the machine in my basement so I can work on it for an extended period. Voltages of the other regulators are OK. I think it's conclusive that the h742a has a fault to be repaired. Next, I re-connected the cable to P9. The DC LO and AC LO wires lead to J18, which feeds DC LO and AC LO to the backplane on my system. Reading >from J18 the DC LO value remains at 3.53v, but the AC LO drops further to 1.72v. I get similar readings from the backplane pins themselves. When I remove the Status Module card (M7235) from the backplane the AC LO on J18 jumps up to 3.53v - i.e. AC LO jumps back to origination levels. Question - Is there is *also* a potential fault in the M7235 circuit related to AC LO, -OR- is it normal for the M7235 to detect and pull down AC LO further forcing the system to halt? I am working to understand the circuits from page 120 of the KD11-A Maint manual http://bitsavers.trailing-edge.com/pdf/dec/pdp11/1140/KD11-A_Maint.pdf My plan is to repair the h742a first and see how it goes, but I'd like a 2nd opinion if anyone has one, regarding the M7235....thanks! photos http://vintagecomputer.net/browse_thread_record.cfm?id=178&tid=8 Bill

11 years, 5 months

GNT-4601 punch cable help

by mloewen＠cpumagic.scol.pa.us

I have a box of old HP paper tapes to read, and am having an awful time trying to build the right serial cable to connect a GNT-4601 reader/punch to a Linux PC. Does anyone have a known good cable diagram and stty settings that will work? Thank. Mike Loewen mloewen at cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/

11 years, 5 months

PDP-11 with ATX power supply

by jnc＠mercury.lcs.mit.edu

> From: Earl Evans > I have a BA11-N mounting box with Q18 9-slot quad-height backplane. > The power supply is toast. Toast, how? Physically mangled, or just not working? If the latter, it might be possible to fix it. (Even if you're not up to that, don't pitch it - someone else might be interested in it as a repair item.) The other thing you could do is install a BA11-S power supply (H7861); some are available on eBay. They are compatible (physically/electrical interface), the H7861 just has a few more amps of +5V. Noel

11 years, 5 months

DEC Legacy 2015, Windermere UK, April 11/12th is just around the corner!

by mark＠wickensonline.co.uk

Sincere Greetings This is a quick email to remind you that DEC Legacy 2015 <http://wickensonline.co.uk/declegacy/> is just around the corner! I've recently updated the web page with some exciting presentations and demonstrations <http://wickensonline.co.uk/declegacy/presentations>including the following topics: *VAX MP - Simulating a SMP VAX* *Mark Wickens, DEC Legacy Organiser* *Unearthing an important historical computer at the computer sheds museum* *Jim Austin, The Jim Austin Computer Collection* *Video Presentation* *Bernd 'vaxman' Ulmann* *An Update from the Living Computer Museum* *Rich Alderson, Senior System Engineer* *The MCPRINT Utility, 30 years in the making* *Malcolm Blunden, retired VMS Systems Manager* *The Future of VMS * *Sue Skonetski, VP of Customer Engagement, VMS Software* *Getting the DEC experience on modern hardware* *Peter Allan, ex VAX system manager and VMS programmer* *HECnet - A worldwide DECnet network* *Mark Wickens, DEC Legacy Organiser* ... and there will be more yet to come. We also now have quite an impressive list of exhibits <http://wickensonline.co.uk/declegacy/hardware> which I expect to continue to grow throughout the next month. Whatever your favourite era of DEC kit you are sure to find something of interest. The registration page <http://wickensonline.co.uk/declegacy/register> allows registration for a single day or the whole weekend. Please come, join in and experience the best computing equipment from the best manufacturer! Kind regards, Mark Wickens *Event Organiser* p.s. please forward this email to anyone else you think might be interested in attending!

11 years, 5 months

2 big anniversaries are looming

by lproven＠gmail.com

Both for the Atari ST... http://mrchimps.lyfordrome.com/AtariStuff/Atari.html http://www.stuff.tv/features/hall-fame-atari-st-computer-kickstarted-home-r… ... and its greatest rival: http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=39821&forum=25 http://fo.hn/amiga30/ -- Liam Proven ? Profile: http://lproven.livejournal.com/profile Email: lproven at cix.co.uk ? GMail/G+/Twitter/Flickr/Facebook: lproven MSN: lproven at hotmail.com ? Skype/AIM/Yahoo/LinkedIn: liamproven Cell/Mobiles: +44 7939-087884 (UK) ? +420 702 829 053 (?R)

11 years, 5 months

Teleray Micricon 82306-3 on ebay

by Arno_1983＠gmx.de

Glen Slick <glen.slick at gmail.com> wrote: > What is an HP 82306C GPIO Interface? Is that the same as thing as an 82306A? > > http://www.hpmuseum.net/display_item.php?hw=1111 > http://www.ebay.com/itm/281557879632 Probably close but not identical. The datasheet (catalog page actually, http://www.premerec.com/pdf/hp11835a.pdf, English version on second page) for the 11835A Data Buffer I have explicitely calls for the C suffix card - but maybe just because it was the current variety at that time. I got the device from a surplus outfit figuring it might come in handy one day, say for demonstrating or debugging bit-serial circuitry, as it can spew out bits at an arbitrary rate between zero and about 4 MHz. It has two banks of 1024 Mbits data memory each that are alternately loaded from the computer and read for driving the serial output, plus some additional memory for configuring an internal state machine and driving auxiliary signals, originally intended for a frequency hopping synthesizer. Intended application for the device was mobile phone and related equipment development; my example came out of a Nokia R&D facility of in Oulu, Finland according to its inventory tag. Sean Caron <scaron at umich.edu> wrote: > Interesting... appears to be some kind of temperature controller... I found > a NASA technical report that mentions it and discusses some of the specs; > apparently it's based on the Signetics 2650A at 1.25 MHz and according to > the spec sheet, it's designed to use standard 4-20 mA interface to > instruments, etc. > > Maybe worth it if someone's looking to hunt down some 2650A CPUs and maybe > some support chips for a vintage SBC project. > > http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870004136.pdf Thanks for the hints. File however doesn't load for me (from Germany). Might not even take ripping the device apart and rebuilding it into an SBC - I find the case, display and keyboard quite nice and would be looking to preserve as much as possible of that. The provided keyboard and display (that look as if they're seven-segment, but might even be alpha-numeric "star" type) could be be quite sufficient for many an application - mostly depending on how much RAM and ROM and which sorts of I/O there are in, can be crammed into or hung off that box - to realize a hex monitor or whatever floats your boat. So Long, Arno

11 years, 5 months

VCF East shirt preview

by evan＠snarc.net

This year we decided to pay homage to the PDP-8 and Spock. :) http://snarc.net/vcfexshirtpreview.gif

11 years, 5 months

General Electric TermiNet 340 printer doc?

by henk.gooijen＠hotmail.com

I picked up a really heavy line printer last week. It is a General Electric TermiNet 340. My searches for doc were not very successful. It seems to be a line printer that prints 340 lines of 132 characters per minute! At the rear side near to the floor is a large rectangular connector. Lucky me, the previous owner had a connection cable. It is a ribbon cable. At one side is the mating rectangular plug, at the other side is an IDC header. Is it possible that this printer is also sold by others using a different name? So far I have not been able to find any documentation. I'd love to get this beast operational! Thanks for pointers, - Henk

11 years, 5 months

Patching vs. new code (was Re: Pascal not considered harmful)

by isking＠uw.edu

On Fri, Feb 20, 2015 at 7:22 AM, Shiresoft <ggs at shiresoft.com> wrote: > > > > On Feb 19, 2015, at 11:35 PM, Chuck Guzis <cclist at sydex.com> wrote: > > > >> On 02/19/2015 08:23 PM, Guy Sotomayor wrote: > >> > >> Nope. It was (and still is) how I write code (sit down and compose at > >> the keyboard). One of my old bosses at IBM once said "Yea, Guy just > >> waves his hands over the keyboard and programs come out". > > > > That would have been impossible in my case, unless I had the most > prodigious eidetic memory in history. > > > > Writing code almost always involved using an on-disk or -tape source > code library. Even if it was new code, there were significant advantages > to creating a library then modifying it as one progressed. > > > > One would typically work with a bound listing or listings and work out > the control system directives to update the existing code base. Remember, > this was in the day of batch processing with almost no access to > terminals. Everything happened on the keypunch. > > > > So for one to remember all of the correction set IDs and sequence > numbers for a group of programs or system programs would be more than > impressive--it'd probably merit a vivisection. > > ;-) > > I never said that I didn't / don't use references while I write code. > It's just that I don't write my code down first. Of course most of what I > do is new (from scratch) rather than modifying existing code. > > When I first started at IBM because build time for our software was about > a week, we'd fix bugs and such with patches. Folks in the lab would stop > looking up the instruction encodings and would just ask me...I could do the > assembly in my head...I'm sorely out of practice now. :-/ > > > My first (paid) programming job was in 6800 assembler, using the Motorola EXORCISER system. It took hours (as in a major part of a day, longer than the work day) to reassemble the entire code base, so we would patch the program in the PROM programmer. We would, of course, back port the changes in symbolic assembler to the source, and every few days just take the downtime hit to rebuild the code base. Keep in mind that this was natively hosted on a 6800 system. Another interesting tidbit: its simple filesystem did not segment files and reuse blocks, so you had to purge old versions of files, preferably before a dozen or so files were lined up after it. In that case, it would tie up the system for way too long while an old file was purged and all the new files were packed into the recovered space, block by block. It was barely a step above magtape. One other note: there was a bug in certain mask sets that required a NOP before you could set the interrupt mask. Since the ENTIRE memory/IO space was 64k bytes, every byte was sacred, every byte was great, and if a byte was wasted?. -- Ian S. King, MSIS, MSCS Ph.D. Candidate The Information School University of Washington There is an old Vulcan saying: "Only Nixon could go to China."

11 years, 5 months

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test-drb