test-drb July 2015

test-drb@ccmp.vtda.org

176 participants
257 discussions

by michael.99.thompson＠gmail.com

Two transistors on the front panel that turn on PC and MA lights failed. They were painful to replace. Hopefully this won't be a weekly ritual. We ran more of the LINC mode processor diagnostics. All that we could figure out with no documentation worked OK. Hopefully someone has the missing documentation that we need. We worked on the TC12 LINCtape controller problem where it had a "LGP GP=GPC PRESET" fault during diagnostics. We are not exactly sure what this part of the TC12 does, something to do with tape groups, a LINC thing. It looks like the diagnostic turns the GP=GPC flip-flop on, then presets (clears) it, then tests to see that it was preset. Most of the time it works OK, and always works OK when run in single step. We replaced the M216 module that contains the GP=GPC flip-flop, but that didn't change the behavior. One of the M222 modules in the TC12 controller routes the GP=GPC signal to the status register. The IC on the M222 that accepts this signal is a SN7453. We have seen lots of failures of this unusual IC on other restoration projects. We swapped the M222 that routes the GP=GPC signal and the diag behavior changed. Next week we will replace the SN7453 and see if that fixes this issue. It will take quite a bit of work to fix the VR14, so we will try to use an oscilloscope in X-Y mode as a display. It might even work! -- Michael Thompson

9 years

Front Panel Update

by rodsmallwood52＠btinternet.com

Hi Guys Well I'm back from holiday. I'm now sorting out what I'm calling the PDP 8/e B model panel. This has the markings for the latest type of selector switch, vertical lines between lamp groups and the line round the selector switch area. If anybody has not got an order in and wants one please let me know. I'm going through the wish lists to see whats next. Probably 8/f or 8/m One off's for old systems where there are very few examples in existance and need custom one off's please email me to discuss. Rod

9 years

what IBM system is this?

by jnc＠mercury.lcs.mit.edu

> From: Simon Claessen > what IBM system is this. Now _that_ is a mainframe!! :-) :-) Noel

9 years

IBM Mainframe update

by jnc＠mercury.lcs.mit.edu

> From: Guy Sotomayor > my IBM Multiprise 3000 S/390 mainframe. > ... > I moved the MP3000 into a more convenient location in my office Dude! If it doesn't take the whole room, it's not a _real_ mainframe! :-) Noel

9 years

Codex 6000 intelligent network processor ?

by jdr_use＠bluewin.ch

Is this something a classicmp'er should be interested in ? What is it anyhow ( since it seems to predate ethernet ) Jos

9 years

IBM Mainframe update

by ggs＠shiresoft.com

It?s been a while, so I thought I?d update folks on what?s been going on with my IBM Multiprise 3000 S/390 mainframe. I?ve updated the webpage for it at: http://www.shiresoft.com/new-shop/Shiresoft/IBM_Mainframe.html#grid <http://www.shiresoft.com/new-shop/Shiresoft/IBM_Mainframe.html#grid> to indicate it?s current status. I?ve managed to boot it up into the version of z/OS (V1R5) that was installed. I discovered that some of the standard users were still present with their default passwords so I was able to log in and do stuff under TSO. I also figured out that one of the standard users had administrative capabilities, so I?m able to fully manage z/OS and make the changes necessary to have it work in my environment and to be able to perform any administrative tasks that I might need to perform. I?ve configured the OS/2 side of things to be on my home network, so I can at lead use one of the various tn3270 programs to log in rather than having to sit as the OS/2 screen and do things. I also reconfigured my 3174 controller so that it could ?talk? to the MP3000 so I can also use my 3179 terminals to log in (which IMHO are much better than the tn3270 programs). During all of this I acquired 8 more 18GB SSA drives so I have enough for a second 72GB array with some spares. I felt really fortunate to have found these drives as they are in no way standard (524 byte sectors) and you need the special carriers to work properly in the MP3000. Not to mention that they are SSA drives! I have put the drives into the MP3000 but have yet to configure them for use. During the checkout of the drives, I discovered that the drive that had been assigned for the ?hot spare? was dead. One of my next tasks will be to assign one of the new drives as the ?hot spare?. Since I have most things working now, I moved the MP3000 into a more convenient location in my office (see picture on the above link) rather than being in the middle of the traffic area of my shop. I?m still going to be doing some ?tinkering? with z/OS before I really knuckle down to (re)learn the various aspects of MVS and TSO. Then off to write some mainframe programs! TTFN - Guy

9 years

TTY 33 - Finally - UPDATE

by rickb＠bensene.com

Happy Independence Day to USA readers, and good day to all others, I found out what the problem was with the tape reader on the 33ASR Teletype. This morning I had some time to do some diagnostics. It appeared that reader trip contacts that are triggered by the cycle clutch were making contact just fine (thanks for the recommendation to check this first). However, there was no sign that there was any current flowing through the contacts, and there was no sign that the reader solenoid was activating. So, I started backtracking, and found the tape reader power supply circuit board. There's a 1/2 Amp Fast-Blow fuse on the board that I tested right away. It was open. I inspected the fuse under a microscope, and there was no sign that the fuse was blown...the filament looked intact. I then found by jiggling the fuse around, it would intermittently show continuity. There was absolutely no sign that the fuse had blown due to an overcurrent condition -- it was more like the fuse had some kind of mechanical fault. So, I grabbed a 1/2 A SB fuse out of my parts bin and installed it, and powered up the Teletype. Put a tape in it (STARTREK listing from OS/8 BASIC), and started the reader. It immediately started reading the tape and printing out the program listing. Good stuff! I have subscribed to the GreenKeys list, and am waiting for approval, which probably may take a little extra time due to the holiday. I need some ribbons, paper, and a new pad for the printhead hammer, but figure I should easily be able to find pointers to sources for these on the GreenKeys list. Now to see if I can find out how to make a facsimile of the tape reader control gizmo that DEC used to allow the PDP 8 to control the paper tape reader, so I can get this terminal properly interfaced to the 8/e. In the meantime, I'm going to hook it up to the Altair 8800 for a little immediate nostalgia. Thanks to all. -Rick

9 years

out-of-mainstream minis

by johnwallace4＠yahoo.co.uk

For the UNIX/68k box possibly labelled Unisys, and in the absence, so far, of anything more definitive: Have a look at Convergent Technologies Miniframe. A reasonable amount of info around. The pictures at http://niki.hammler.net/wiki/Convergent_Systems_MiniFrame may be helpful - one is of a back panel with multiple serial ports and a couple of others. That website is in German but others are available in other languages, and anyway a picture speaks approximately 1K words. No guarantees, but worth a look by the sound of it. I had the mixed fortune to use one of these briefly in the mid 1980s, primarily to use troff/nroff etc for documentation generation and software testing. Real development work was done in a platform-independent manner on a VMS box before being tested on the UNIX box. The System-V-based (?) Minframe software at the time was so unproductive that most of the document production was also done on the VMS box (a VAX11/725, for goodness sake, more productive than a hip/trendy UNIX box). Write in troff/nroff using EDT on VMS, put through a simplistic translation from troff/nroff to RUNOFF, check the output, repeat till it was about right, with only the final version being generated from troff/nroff on the CT box. My recollection is that the 68K OS we had didn't do demand paging, just swapping, even though if it really did have a 68010, demand paging would have been possible (and preferable). I believe these boxes were rebadged by various other vendors; the one I had was reportedly a prototype prior to being rebadged by Gould. Maybe Unisys were doing the same. It may have been Gould's (not CT's) software. Have a lot of fun john wallace ==================================================================== Re: out-of-mainstream minis Saturday, 4 July, 2015 0:54 From: ? ? "mark at markesystems.com" <mark at markesystems.com> To: ? ? cctalk at classiccmp.org In the late 80?s, I bought from a surplus/junk shop a (by then somewhat obsolete) Unix computer, branded UniSys, I think.? It had 10 serial ports; one was the primary console, one was intended for a printer, and the other 8 were regular user TTYs.? The processor was a 68000 (not 010, 020, or anything else), I don?t remember how much memory, and it had an integral full-height hard drive as well (60 mB, maybe?). When I say Unix, I mean real System-7 Unix ? not Linux or any other *nix.? I thought it was really a pretty neat system ? 8 (or 9) users and a printer, just perfect for a small office ? or my apartment at the time, which had a terminal or two in every room.? I learned how to program in Unix on that machine, since it matched exactly the System 7 manuals I had. Sadly, time moved on, I got married, and got rid of a bunch of ?useless junk?, like that computer. Recently, I?ve been reminiscing and poking around some on the Web to try to find information about it, but it seems to have vanished completely with nary a ripple.? Has anyone else stumbled across this unit, or at least have any knowledge of it?? It was a black case, about the size of a standard IBM-PC, with ten serial ports on the back and not much else.? I?d sure be interested to know where I might locate data about that unit, or (gasp!) possibly even an existing one... ~~ Mark Moulding

9 years

Codex 6000 intelligent network processor ?

by jdr_use＠bluewin.ch

Is this something a classicmp'er should be interested in ? What is it anyhow ( since it seems to predate ethernet ) Jos

9 years

How many use old browsers (e.g. =< Netscape 4 or IE 6) as their ONLY source of web content?

by jhfinedp3k＠compsys.to

>Jerome H. Fine wrote: > >Jerome H. Fine wrote: > >> >Terry Stewart wrote: >> >>> I'm engaged in a Retrochallenge project where I'm recoding my >>> classic-computers.org.nz site to make it suitable for mobile >>> platforms. I >>> want to modernise the code as well, making it as close to HTML5 >>> standard as >>> I can >>> >>> The RetroChallenge blog site is here. >>> http://www.classic-computers.org.nz/blog/2015-06-29-recoding-classic-comput… >> >> I checked this site under WinXP and found no problems. The software >> is very old, but a quick search did not locate the version. > > As I mentioned, I backup up my Win98SE system, then accessed all > of the links under Netscape 7.2 without any problems. Sorry about the SPAM KEY being included in the Subject line. The server which handles my e-mail frequently does that and I forget to remove it from the Subject line when I reply. Jerome Fine

9 years

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test-drb July 2015