test-drb August 2015

test-drb@ccmp.vtda.org

206 participants
257 discussions

Power supply connector pin crimping, and 8-inch FDD power connectors (another chapter in the Quay 900 saga)

by spacewar＠gmail.com

Last week I wanted to test some half-height eight-inch double-sided drives (NEC, Mistubishi, and Qume) on the Quay 900. I cabled a Mitsubishi drive in place of the original CDC/MPI 9406 77618022 drives, and the machine apparently wouldn't reset properly, since I wasn't getting the prompt from my ROM monitor either on power-up or by manually resetting it. I poked around a bit and discovered that the +5V DC supply was at about 0.7V. I disconnected the Mitsubishi, and it still didn't work, and the +5V was still at 0.7V. Uh oh, what did I break? After a lot of pulling of hair, gnashing of teeth, and sacrificing a chicken at midnight, I discovered that +5V pin in the connector that plugs onto the switching power supply was not crimped properly. It was partially crimped, but the wire was just loose. The cable connector is an AMP (now TE) 87025-7 "Ampmodu" 0.156-inch pitch shell which accepts 102103-3 rectangular crimp receptacles. The shell has 20 positions, of which they inserted a keying plug in position 1, and only use contacts in some of the even positions from 2 though 20, because the header on the power supply PCB only has every other pin loaded. TE no longer makes the 87025-7, but they still make the 87025-8, which is apparently the same thing without the part number being stamped on the housing. I don't need another housing though, just a pin, because without the right extraction tool I hadn't been able to get the old pin out without mangling it a fair bit. Mouser and Digikey sell the pins in small quantity for $0.50 each, which seems absurdly high for a crimp pin with only tin plating. (There's another part number for a gold contact, but distributors don't stock it.) Just for the hell of it, I looked up the TE manual (hand) crimping tool designed for this pin, p/n 90274-2. It sells for over $6500. There is a used one on eBay for $75, but I've had bad experience buying used crimping tools. The only crimping tool I have on hand is designed for terminals with a round shell that just have to be crimped flat, vs. for terminals with V-shaped edges that have to be folded back in, as is typical of Molex pins and the like. I decided to order an inexpensive ratcheting crimping tool from an Amazon seller. It's an Iwiss SN-28B, also sold under the Estone and other brands. The Iwiss was $19. I couldn't tell from the photos whether it would be suitable. It turns out that it worked perfectly for the TE pins. It has two pairs of dies stacked with one pair having a larger profile, so it does crimp both the conductor and the insulator at the same time, which I wasn't expecting for a sub-$20 tool. That got the machine working again, and I verified that the CDC/MPI drives are still working, or at least working as well as they were before. I'm still seeing a lot of unreliability when using double-density on the highest-numbered tracks (closest to spindle). Could be the wrong amount of precomp, or the low-quality data separator design. Since one of the two MPI drives gets more errors than the other, there may be some issue with drive alignment or drive electronics adjustment as well. I unplugged the MPI drives and plugged in the Mitsubishi. Once again the machine wouldn't reset properly. It turns out that even though this bizarre variant of the 9406 uses the Shugart pinout for the data connector instead of the MPI pinout, and uses the same DC power connector as the Shugart, instead of the header used in normal MPI 9406 drives, the DC power connector pinout for the MPI does NOT match the Shugart DC pinout, as also used by the various half-height drives I want to try. I'm becoming less and less impressed with these MPI drives as I learn more about them. With the Mitsubishi cabled up to the Quay, but using a separate DC power supply with the correct pinout, I was able to verify that the Mitsubishi drive actually works fine. When used with the Quay FDC, it does need some retries for double-density on the inner tracks, like the MPIs, but it doesn't need as many retries as either of the MPI drives.

9 years

Looking for RL8A controller card

by charlesmorris800＠centurytel.net

I have a PDP-8/A with a flaky RL8A (M8433) controller card. I can't track the fault down. I've spent enough hours on it by now that I'd just as soon buy another one. Anyone have one to sell? Or possibly could repair mine (for compensation)? thanks Charles

9 years

OpenVMS TCP/IP Services 5.3 availability

by RichA＠LivingComputerMuseum.org

We are currently running TCP/IP Services 5.1 under OpenVMS 7.3 on the museum's VAX-11/780-5. The telnet listener has a known issue which is fixed in v5.3, but we have not been able to locate this (we've asked in the right places). Was this on a ConDist platter? Or was it made available in some other way? We have a perpetual license for VMS, and renew our other licenses annually, so PAKs are not an issue. Would someone be willing to loan us the install media? Or otherwise make this available? Thanks, Rich Rich Alderson Sr. Systems Engineer Living Computer Museum 2245 1st Ave S Seattle, WA 98134 Cell: (206) 465-2916 Desk: (206) 342-2239 http://www.LivingComputerMuseum.org/

9 years

More on manuals plus rescue

by kevin_anderson_dbq＠yahoo.com

Wow, I have just looked at the manuals collection at the Internet Archive site. I honestly can say I don't like it, but I will say it is because this is not how my mind works in organizing stuff. I am immediately turned off by the tiling of 'cards" on the screen and the categorizing of collections. I know it more closely matches tablet apps and how they seemed to be designed, but I can also say, although I am the user of a tablet, I am not always happy with that approach. Even switching to the list view within IA didn't help much. I think it is great that Bitsavers material can be saved in more than one location, whether that be identical mirrors on multiple servers or with material copied into another environment. The point being the access to material and minimizing any risk of it all disappearing at once. But I agree that correct attribution of where material comes from is also very important. And multiple interfaces to how to search and find information can be fine to, as we all think differently. I just happen to prefer collapsible trees, textual lists, and drill-down methods more than I do other newer visual methods. My previous experience with Internet Archives has been mainly looking for old videos from the 1940s, 50s, and 60s through primarily the Prelinger archive, plus some texts and books that I found through Google and other search engines, and in using the Wayback machine. Seeing this new interface to the Internet Archives made it clear that I haven't checked IA since they apparently redid this interface, and all I can't say is I don't like it, and clearly if I can't find the item I need from IA through a Google search, then I won't be trying to find it directly from Internet Archives. The interface used at the Internet Archive is not Jason's fault. And certainly not so if the interface changed after Jason had already started his project. But I also feel that this collection at Internet Archive didn't necessarily help in useful ways to archive the older computer stuff, at least not that I can see from this initial review. Or if the collection is still good, the web interface is hindering a proper appreciation of that material and access to it. It also doesn't help that modern implementations of web content is all database driven (which the Internet Archive is one such site), which on the surface ought to be great, but in reality isn't when one no longer has as much control over the levels and depths of web pages in the same way as direct folders on a file server. The more flat and eclectic nature of today's web pages, with the expectation that one will "leap" all over the place within a largely flat structure, possibly employing filters to limit choices, is much less useful in this case for archiving and organizing the material in question than say hierarchical tree structures. At least in my opinion.... Kevin Anderson Dubuque, Iowa

9 years

5.25" floppy disk storage.

by ard＠p850ug1.demon.co.uk

Something non-technical from me for a change. Most of you in the UK will have come across 'Really Useful Boxes' and probably use them for storing cables, screws, etc (I wish they made anti-static ones ;-)). Anyway what I hadn't realised until today is that the 3 litre size is just the right size for storing 5.25" floppy disks (in their cardboard covers), it will take about 80 of them with enough free space to extract them easily. Finding modern boxes for 5.25" disks is not that easy (I have not found the size for 8" disks though :-() Even better, at the moment, Rymans (at least round here) have them on sale at 4 for \pounds 10.00 (normally \pounds 3.99 each). -tony

9 years

MAINDEX-11 CZKMA Diagnostic?

by ben＠bensinclair.com

I'm again trying to debug my PDP-11/23, and I believe I'm having trouble with my M8067-LB/MSV-11 memory. According to the manual, there is a diagnostic program called CZKMA (for my 18-bit system), but I can't seem to find it. I have all of the xxdp images from AK6DN, but this one doesn't appear to be on any of those. Some searching shows references to it and even a (poorly) scanned source listing, but does anyone know if I can get it on a TU58 image or another format? Thanks! -- Ben Sinclair ben at bensinclair.com

9 years

DECdatasystem 534 (11/34) and VT52 for sale at VCF Midwest 10

by julian＠twinax.org

I will be selling my DECdatasystem 534 and VT52 at the show. Cabinet rack, 72x24x26".11/34a, 32kW of core and A/D+D/A cards. System runs fine and drops to a console prompt, and passes all the diags I've been able to throw at it. I've restored all the foam filters and the cabinet was pressure washed a couple of years ago so no funny smells or mold. I have no peripherals for it. The VT52 does not power on. I'm entertaining pre-show offers, so let me know privately if you are interested in either of these items. Julian

9 years

Clearpoint DCME/Q4E configuration

by jnc＠mercury.lcs.mit.edu

> From: Johnny Billquist >> Yes, and if you plug one of their PMI memory boards into a Q/Q >> backplane, it will emit magic smoke, too! :-) > I don't remember if I've ever tried that Don't! :-) As the MSV11-J manual puts it, "NOTE: Insertion of the MSV11-J in a Q-Q backplane may damage other components or the memory itself. The PMI bussing on the MSV11-J's CD connectors is not compatible with the +12V bussing on the Q-Q backplane." > but I can believe that some jumpers would need to be moved around for a > Q-Q slot. ... No jumpers moved. There are no jumpers to configure an MSV11-J for Q/Q slots. (It's only got 4 jumpers total, two of which are factory config; the others are battery backup power.) > By CRC, I guess you mean ECC. Yup, sorry, not completely awake when I typed that, I guess! :-) > And with 37 bits, I think it should have ECC. ECC depends on the CSR > address set correctly. But I could be wrong as well. I think it needs more than 5 bits, for 32. The MSV11-J uses 6 bits, for 16. >> However, when I plugged the other one in - nada. No response at all; >> the boot PROM bitched about 'no memory at 0'. So I'm not sure _what_ >> that configuration is for. > Would sound like it was configured for a non-zero start address maybe? I did wonder that, but why would anyone configure a 4MB card for a non-zero start address? Anyway, I have yet to investigate this jumper configuration more extensively - later. > But if you tried with the switches/jumpers the same as on the board > working then it sounds like it would just be broken. No, that board (mostly, except for the "Memory CSR" error) worked with the jumpers in the _PMI_ configuration. Although I suppose some of the circuitry for use in the non-PMI config could be broken, but I think not. (More below.) >> The boot PROM was complaining about "Memory CSR Error" .. _but_ the >> memory was shown (by the boot PROM 'map' command) as PMI, and my own >> memory-test program showed it was all working OK. > And then the cards also have a CSR register or two, which is used for > various things. And they are expected to be at specific addresses. > ... > If you have a memory starting at address 0, there should be a CSR at a > specific address as well So I did some experiments, with very interesting results. I took the card that got the "Memory CSR Error", plugged it in, and ran a 'find all device registers' program in the system with it in. It showed a single memory CSR, at 172100. I then plugged in the card that _does_ pass the startup test, and it also had a single register, at that same location. So I guess it must be something about the way that register operates, that is different between the two cards. Which is possible; as I mentioned, there are a few programmable chips which are different revs. (And one large custom chip, which _seems_ to be a different rev.) Oddly enough, if I operate that 'broken' card in QBUS mode (after the CPU), not PMI mode (before), it _does_ pass the built-in self-test!!! Which argues that its failure to operate in QBUS mode, with the non-PMI jumper settings, is not because the hardware to operate in QBUS mode is broken. So I have no idea what the other set of jumper settings is for! Blast, I sure wish we had documentation for these things! Noel

9 years

Looking for a VAX 9000

by Sue.Skonetski＠VMSSoftware.com

Dear Group, My name is Sue Skonetski I am a vintage Digital, Compaq and HP person and now with VMS Software. It is not a typo I am really looking for a VAX 9000. Thanks, Sue Sue Skonetski VP of Customer Advocacy Sue.Skonetski at vmssoftware.com Office: +1 (978) 451-0116 Mobile: +1 (603) 494-9886 Mit freundlichen Gr??en ? Avec mes meilleures salutations

9 years

← Newer
1
...
9
10
11
12
13
14
15
...
26
Older →

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb August 2015