test-drb March 2018

test-drb@ccmp.vtda.org

158 participants
173 discussions

by jnc＠mercury.lcs.mit.edu

> From: Sytse van Slooten > digging through the documentation of KL-11 and DL-11 I did find > references to generating a break (bit 0 in the XCSR). But not on how it > would be received. ... How did a DL-11 like interface signal the > reception of a break? As JohnW says, framing error. FWIW, the UART chips used back then actually produce a 'framing error' output, which is sent straight into that bit in the RCSR. > And how did the operating systems and software deal with it? Was it > actually used at all? Different systems used it for different things. Unix V6 used 'break' on dial-up lines as the signal to switch speeds when you first connected up - it would try 110, then 150, then 300. (Later this got extended, I expect - too lazy to check.) I see the hacked PWB1 Unix at MIT used it to send an interrupt: if (c & FRERR) { signal(tp->t_pgrp, SIGINT); return; } That's as far as my knowledge extends, others may know of more uses. Noel

6 years, 8 months

CXY08 and DELQA compatible with 2.11bsd?

by bob＠jfcl.com

Does anyone know offhand if the CXY08 (M3119) and DELQA (M7516) work with 2.11bsd? I think the CXY08 has the same programmer interface as the DHV11, and I'm hoping it works with the 2.11bsd dh driver. Ditto for the DELQA and the qe driver. If somebody knows for sure, though, I'd appreciate it if you can save me the trouble of installing it all just to find out it doesn't work. Thanks, Bob

6 years, 8 months

RL02 Question

by aaron＠aaronsplace.co.uk

Sorry to keep bothering you all with RL02 questions. I think I am nearly there. It seems my head cleaning in a warm bath of isopropyl alcohol was a success. I bought a tested RL02 pack and loaded it - no bad sounds, I can extend the heads all the way. So that's good. I have supposedly a working RL02K pack, and seemingly good heads. After I load a pack however, it goes into fault mode. Checking through the test points on my scope, there is no survo burst data until I push the heads 3-5mm further forward. So it seems to me that the heads are not loading far enough into the pack. I loosened the head alignment screws to move the heads all the way forward, tightened them back up, and tried loading the pack again. It stopped again, 3-5mm short of track 0. So moving the heads forward didn't seem to make any difference. I have tried a different control board, and read/write amplifier board, with no success. Has anyone else experienced this? Is there some sensor which I am not seeing? Thanks, Aaron. -- Aaron Jackson PhD Student, Computer Vision Laboratory, Uni of Nottingham http://aaronsplace.co.uk

6 years, 8 months

RT-11 V4 MU-BASIC help

by fritzm＠fritzm.org

Hello all, I would like to try and get MU-BASIC working on my PDP-11/45, under RT-11 V4. The best bits I've been able to find to work with so far are the RK05 image here: http://bitsavers.trailing-edge.com/bits/DEC/pdp11/discimages/rk05/rt11v4-mu… ...but I've not had much success getting this to work under simh. Using the 1USER.CNF configuration file in this image, no matter how I configure the machine, I get either traps, halts, or stack violations when issuing the first command in basic. Trying to rebuild MU-BASIC using the indirect files in the image results in a linker barf on some undefined symbols. Has anybody else here had much luck getting MU-BASIC up and running under RT-11 V4? Is there an alternate image or distribution kit somewhere that I could try to work with? thanks much, --FritzM.

6 years, 8 months

TRS-80 Siting

by bill.gunshannon＠hotmail.com

I hate to suggest that people actually watch the garbage, but a recent Safe Auto Insurance commercial features a girl typing on a TRS-80 Model 4 with the badges removed. It's the one that starts out with a Disco skit.? The TRS-80 shows up in the very last part. bill Don't shoot me, I'm only the messenger. :-)

6 years, 8 months

break on pdp11 serial ports

by cclist＠sytse.net

Hello all, I've been playing around with some ideas for designing some hardware to connect peripherals to an fpga for my vhdl pdp-11. One of the things that should definitely be on there, next to sd cards and leds... are some serial ports for console terminals etc. I've spent some time to create a prototype usb to serial thing that handles more than one port. Works kind of neat. While doing that, I stumbled on the concept of break. Up to now in all of the pdp2011 history I have ignored it, the serial port that sits at the pdp-11 side of things is about the most minimum that does the job. And that is good enough for a lot of things, actually - I didn't really miss a break signal so far. Anyway, digging through the documentation of KL-11 and DL-11 I did find references to generating a break (bit 0 in the XCSR). But not on how it would be received. That's where the questions start. How did a DL-11 like interface signal the reception of a break? And how did the operating systems and software deal with it? Was it actually used at all? I think to remember several occasions of impatiently banging the break key back in the day, but it is a bit fuzzy why (and if it had any result). anyway, I'm trying to judge whether it makes any sense to put effort into making the break thing work on my serial converter thing... any kind of input is greatly appreciated! cheers Sytse

6 years, 8 months

RAID? Was: PATA hard disks, anyone?

by cctalk＠ibm51xx.net

-------- Original message -------- From: Chuck Guzis via cctalk <cctalk at classiccmp.org> Date: 3/28/18 10:02 AM (GMT-08:00) To: Paul Koning via cctalk <cctalk at classiccmp.org> Subject: Re: RAID? Was: PATA hard disks, anyone? >I know of no RAID setup that can save me >from stupid. Chuck, As we say in my day job "there is no curing stupid" ;) -Ali

6 years, 8 months

DEC 3000 (alpha) faultfinding

by cruff＠ruffspot.net

On the AXPpci33 board, the SROM is also an 8 bit device. What happens is that the CPU reads in a bit stream into cache at power up reset, where the specific bit stream is selected by the jumper position on the board. In effect the SROM can contain up to 8 bit streams. Some of them will make use of the SROM console port.

6 years, 8 months

RAID? Was: PATA hard disks, anyone?

by cctalk＠ibm51xx.net

-------- Original message -------- From: Fred Cisin via cctalk <cctalk at classiccmp.org> Date: 3/27/18 5:51 PM (GMT-08:00) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: RAID?  Was: PATA hard disks, anyone? How many drives would you need, to be able to set up a RAID, or hot swappable RAUD (Redundant Array of Unreliable Drives), that could give decent reliability with such drives? 10 - Two sets of 5 drive? RAID 6 volumes in a RAID 1 array. You would then need to lose 5 drives before data failure is imminent. The 6th one will do you in. If you haven't fixed 50 percent failure then you deserve to lose your data.? Disclaimer: this is my totally unscientific unprofessional and biased estimate. My daily activities of life have nothing to do with the IT industry. Proceed at your own peril. Etc. Etc. -Ali

6 years, 8 months

SGI SN-921 dial box (978-0804) (was Re: IBM 6094-010 "Dials" protocol?)

by ethan.dicks＠gmail.com

On Sun, Mar 25, 2018 at 6:09 PM, Ethan Dicks <ethan.dicks at gmail.com> wrote: >> SN-921 (2.1mm barrel jack for +5V) >> https://upload.wikimedia.org/wikipedia/commons/7/74/Sgi_dialbox_sn-921_fron… > > http://yehar.com/blog/?p=3471 > > The (Seiko?) SN-921 can apparently be powered via DE9 or the 2.1mm > jack next to it... > > 1. GND > 2. SERIAL OUTPUT (?9 V) > 3. SERIAL INPUT > 4. POWER IN +5 V > 5. POWER IN +5 V > 6. NC > 7. NC > 8. GND > 9. NC Now that I've poked around in the innards, I can say that this pinout has a slight mistake in it. It should be: 1. GND 2. SERIAL OUTPUT (?9 V) 3. SERIAL INPUT 4. POWER IN +5 V 5. POWER IN +5 V 6. NC 7. GND 8. NC 9. NC There are mentions here and there about how to hook up this dial box using the +5V power jack and DE9 pins 2, 3, and 7. I can confirm from direct examination that pin 7 is a ground and 8 is NC on the PCB (and that 4 and 5 are connected directly to the center pin of the 2.1mm power jack). -ethan

6 years, 8 months

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test-drb March 2018