test-drb January 2016

test-drb@ccmp.vtda.org

172 participants
198 discussions

by ard＠p850ug1.demon.co.uk

I am not sure this fits in with the current topics of this list on the grounds it involves real old hardware, but anyway.. I am currently trying to restore a VAX11/730. I got this about 20 years ago and dismantled it to get it home. For various reasons I never put it back together, I am doing that -- slowly -- now. It's the version in the half-height rack with an R80 at the bottom, then the 11/730 CPU box, and a TS05 on top. I know I am going to have problems with the storage devices, for the moment I am jsut trying to get the CPU running. I've remounted it in the rack, got all the ribbon cables in place, tested the PSU, etc. Minor PSU problems (leaky transistor) but now fine. Powering up gives the expected ROM> prompt on the terminal. Of course all you can do at that prompt is load the microcode from the TU58, so that is what I am trying to get working. And getting nowhere! Firstly the TU58 controller is not passing the self-test. I am pretty sure the 8155 RAM/IO chip is dead. I have removed this and fitted a DIP socket. The rollers were of course dead. I have made hubs and fitted an O-ring of a suitable size. This may not work correctly, but it does seem to move the tape. I have a couple of tape cartridges, the Console microocode tape, and amazingly the belt seems good in them. The motor does get the tape whizzing past the heads. I tried an 8155 borrowed from another device. The controller then passes the self-test (the LED comes on and stays on) but all I get is DD1: Read Error messages and the tape often runs off the spool (rethreading it is something I've got quite good at!). I tried a RS232 analyser between the TU58 and the VAX. Very odd. Either my RS232 anaylser drops 00 bytes or the TU58 sets short result packets. The meaningful bytes (response code, etc) are there, but things like the sequence number are not. Odd... With the 8155 removed, I can pull port pins (on the socket) high and low to start the motor, select drive, track, direction, etc. I've done that and put a LogicDart on the output of the comparator in the read amplifier. According to the manual, the tape is recorded at 800bpi and runs at 30ips. So I get that a bit should take around 41us. And a bit starts with a rising edge, the position of the falling edge (recorded at 1/4 or 3/4 of the bit time) determines whether it's a 0 or 1. Well, sometimes that's what I see on the LogicDart. Sometimes I see a 1:1 square wave with a period of 40-odd us. Does anyone have any sensible ideas as to what to try next. At the moment I have no idea if it's the tape, heads, roller or what.... -tony

8 years, 5 months

P112 CP/M computer kits still available

by dave＠661.org

FYI, I still have lots of P112 CP/M computer kits for sale. Please buy one or several. See http://661.org/p112/ -- David Griffith dave at 661.org 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?

8 years, 5 months

seeking test program for klh10 and panda display

by dave＠661.org

In order to perfect my new USB-based Panda Display, I'd like to know what to expect on the display. Does anyone here have a pdp-10 program that will put a recognizable pattern on a parallel Panda Display? In particular, I'm looking for whatever is causing the action in this video to happen: https://www.youtube.com/watch?v=g_LcQ5apODg -- David Griffith dave at 661.org 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?

8 years, 5 months

PDP-12 restauration in center Germany (J?rg Hoppe)

by michael.99.thompson＠gmail.com

> > Date: Sun, 10 Jan 2016 17:16:17 +0100 > From: J?rg Hoppe <j_hoppe at t-online.de> > Subject: PDP-12 restauration in center Germany > > Hi, > > in case somebody needs companions for cross-tests or likes to exchange > thoughts: > > A few month ago we bought a PDP-12 and are restoring she since then. > > There is no online-diary about progress (the maching is eating up all > time), but see here: > > http://c-c-g.de/index.php?option=com_content&view=article&id=311:pdp12-geka… > > The 12 is complete with no visible damages and has some undocumented > add-ons (they always have). > Especially a MOS memory extension was plugged off very soon. > > Luckily we could organize an 95% complete 2nd module set. > > After console exchange (we had indeed a 2nd one!) and much trouble with > cpu logic, > we can now execute opcodes with DO and FILL/EXAM the core memory. > > Contact me if you like to visit us, we're sitting near G?ttingen > (between Kassel and Hannover). > > Joerg > Joerg, Take a look at a picture of our PDP-12. It has a PDP-8/I next to it as in your picture. http://www.ricomputermuseum.org/Home/equipment/dec-pdp-12/dec-pdp-12-restor… We also have MAI and Wang systems. -- Michael Thompson

8 years, 5 months

TU58 problems

by blstuart＠bellsouth.net

On Sat, 1/16/16, tony duell <ard at p850ug1.demon.co.uk> wrote: > I tried a RS232 analyser between the TU58 and the VAX. Very odd. Either > my RS232 anaylser drops 00 bytes or the TU58 sets short result packets. The > meaningful bytes (response code, etc) are there, but things like the sequence > number are not. Odd... > > Does anyone have any sensible ideas as to what to try next. At the moment > I have no idea if it's the tape, heads, roller or what.... If it were me, I'd start by setting up some tests to determine what exactly the protocol analyzer is doing. If it really is dropping 0 bytes, then I'd probably hack up a home grown capture using a couple of serial ports. If the controller and the VAX really are speaking the right protocol to each other, then it's time to worry about the correctness of the data. On the other hand, if the controller really is not sending all the bytes it should, I'd check for bit rot in the EPROM. BLS

8 years, 5 months

Oddball floppies for trade - 8", HS (outer edge), weird cutout

by COURYHOUSE＠aol.com

first time I have seen such a thing... Ed# In a message dated 1/16/2016 6:46:54 P.M. US Mountain Standard Time, michael.99.thompson at gmail.com writes: >From: Jay West jwest at classiccmp.org > >I have two "flippy organizers" (that's around 20 floppies each) full of >these oddball floppies. > >Picture at >https://www.flickr.com/photos/131070638 at N02/22020178558/in/dateposted/ > >They are 8", hard sectored, and the sectors are on the outer edge rather >than the hub, and there is an odd cutout on one edge that goes inside the >drive. > >I know I don't have a machine that uses these, so they are available for >trade. > >J Jay, The RICM just received a PDP-11/05 donation with an attached AED 2500 diskette subsystem. The drives are Memorex 651, and use the oddball diskettes you have. We could really use these diskettes. Is there any chance that you still have them? -- Michael Thompson

8 years, 5 months

Oddball floppies for trade - 8", HS (outer edge), weird cutout

by michael.99.thompson＠gmail.com

>From: Jay West jwest at classiccmp.org > >I have two "flippy organizers" (that's around 20 floppies each) full of >these oddball floppies. > >Picture at >https://www.flickr.com/photos/131070638 at N02/22020178558/in/dateposted/ > >They are 8", hard sectored, and the sectors are on the outer edge rather >than the hub, and there is an odd cutout on one edge that goes inside the >drive. > >I know I don't have a machine that uses these, so they are available for >trade. > >J Jay, The RICM just received a PDP-11/05 donation with an attached AED 2500 diskette subsystem. The drives are Memorex 651, and use the oddball diskettes you have. We could really use these diskettes. Is there any chance that you still have them? -- Michael Thompson

8 years, 5 months

ISO: Unibus SCSI disk controller

by derschjo＠gmail.com

(...but then who isn't). I'm looking for a mass-storage device for my PDP-11/44, and I'm having worse and worse luck with my current solution, an Emulex SMD controller -- drives just keep going south on me (the controller works fine, though...) I know how hard these things are to find, but if anyone has a Unibus SCSI controller they're willing to trade for something else, let me know. I have a variety of gear, PDP-11 and otherwise, drop me a line and maybe we can work something out? Thanks as always, Josh

8 years, 5 months

Need cheap source for anti-static chip tubes

by snhirsch＠gmail.com

Title says it. Perhaps I'm being stupid about search terms, but I'm not finding much of anything on eBay. One seller has TSOP tubes, but I need plain, old 300mm DIP tubes. End plugs and pins for them as well. Plenty of companies offering them on the web, but all are oriented for production quantities. I'd be happy with 20-25. --

8 years, 5 months

PDP-11/44 w/ 2 RLxx drives for free pickup in San Antonio, TX

by nf6x＠nf6x.net

I got this comment on my blog today: http://www.nf6x.net/2013/11/my-new-dec-pdp-1144-project/#comment-248370 "I have a 11/44. 2xrl drives. And misc extras. It is going in the dump in 2 weeks? do you know anyone who wants it FREE? schematics and rsx 11 mnuals and a few unix things? helotianmoon at gmail.com must pick up san antonio texas pick up by 12-24-2016" I would pick it up myself if I was local. Somebody grab it, please! -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

8 years, 5 months

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test-drb January 2016