- test-drb@ccmp.vtda.org - classiccmp.org

archiving data, was RE: Media Longitevity/Care

by msokolov＠ivan.Harhan.ORG

willisjo at zianet.com wrote: > However, I am a tad concerned about what will happen > to our prized hobby when such items as 9-track tapes, > TK50s, and TU58 DECtape-IIs truly become absolute > unobtainium. As I have stated many times before, I believe the solution is for us to open our own factories to make them. MS

21 years, 2 months

11
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Unexpected floppy behavior...

by melamy＠earthlink.net

termination is 150 ohms (for 5.25" floppy drives) to +5vdc... one of the reasons that one drive only can be terminated otherwise the output drives can't handle the current and if there is no termination then there is not a valid logic high level. best regards, Steve Thatcher -----Original Message----- From: Bill Sudbrink <wh.sudbrink at verizon.net> Ah, yes, in each of my tests, the unpowered drive was set for DS2 (drive B) and TM (termination) and was at the end of the cable. But, I thought that the termination was to ground?

21 years, 2 months

2
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Unexpected floppy behavior...

by pete＠dunnington.u-net.com

On Mar 20 2005, 19:20, Bill Sudbrink wrote: > After a good bit of > trying to figure out what was wrong, I discovered that the > +5 volt pin in the power connector I was using for the #2 (B) > drive had pushed out of the nylon plug so that the drive was > unpowered. Having either of the drives unpowered on the cable > caused the other drive to screw up. The two drives cooperate > just fine when both have power. I don't remember ever seeing > this kind of problem before... I seem to remember having unpowered > drives hanging off of cables with no ill effects. I guess that > some of the signals (write gate for instance) must be getting > pulled low by the unpowered unit. Is this normal floppy > behavior and I'm just remembering wrong? Usually that's OK. Is perhaps the one without power also the one with the terminators, or do neither have terminators? -- Pete Peter Turnbull Network Manager University of York

21 years, 2 months

2
1
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TU56/TC11 restoration - Power supply question

by dvcorbin＠optonline.net

> Is the H720 the correct power supply for the TC11/TU56 > combo, as is indicated in some document I've looked at? > I'm at work and don't have my notes. Are there other > compatible DEC power supplies that will work with the > TC11/TU56? > On a related note...any special concerns on an initial powerup of a TU-56 that has not been turned on for possibly 5+ years....??

21 years, 2 months

17
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Low-Level PC Formatting Using Debug Commands

by marvin＠rain.org

I just ran across this and thought it might be of interest for anyone doing a low level format on a PC (not AT) type controllers. It was taken >from a February 13, 1989 issue of Tech Times that appears to be a ComputerLand Confidential publication (this is a copy.) My usual procedure was to unassemble C800:5 or C800:6 and G=????:? the address that was a jmp instruction. I've never used the :800 or tried to format a Xebec controller. ******************* Company Debug Command Adaptec -G=C800:CCC DTC -G=C800:5 Omti -G=C800:6 Western Digital -G=C800:5 or -G=c800:800 Xebec Series of commands -l322 -l321 -o322 0 -l321 -o320 04 -0320 00 -o320 00 -0320 00 -0320 05 -0320 07 (use 17 if embedded servo dr) At this point, the LED on the drive should come on to indicate that the drive is formatting. When the light goes off, coninue: -l321 -l320 The last entry should get 00 status back, indicating a successful format.

21 years, 2 months

4
3
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Star Trek update

by pete＠dunnington.u-net.com

If anyone's interested, I've recently updated my Star Trek page somewhat. More BASIC versions, a little more blurb, and Java and Z-code versions at http://www.dunnington.u-net.com/public/startrek/ As always, corrections, additions, and comments are welcome. Anyone got a FORTH or APL version? -- Pete Peter Turnbull Network Manager University of York

21 years, 2 months

4
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$2000 Black Apple (?) - scam ?

by pete＠dunnington.u-net.com

On Mar 20 2005, 16:39, Dave Dunfield wrote: > Couple of weeks ago, I was contacted by a guy who said he had seen my site, > and has an "Black Apple" (Bell and Howell edition of Apple II for schools) > I responded by asking him for a price - he said $150 > He's left me on his mailing list, and since than has reported that he had > an offer for $500, then $1000, and this morning he says he has an offer for > $2000. I corresponded with him again and he says: > >ok right now got offer for 2000 from people in uk. have 2 different people > >in uk that want it for good money. There's one on eBay right now, in good condition, with working drives, at $355 Canadian with 19 hours to go. I've seen them go a little higher. I can't imagine why anyone would pay very much more than that, and I suspect he's not had any offer near $2000. If he had, and you'd already told him you weren't interested at $150, why would he bother to contact you again? Anyway, don't forget you'd pay VAT and possibly import duty if you bought one from the States. -- Pete Peter Turnbull Network Manager University of York

21 years, 2 months

1
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Catweasel (MK3) floppy controller question..

by pat＠computer-refuge.org

I figure this might be a decent place to ask.. Does anyone know of a program I can use (preferably under Linux, but DOS would probably work as well) to read a flux-transition level image off a disk using a catweasel card? I'm trying to read some 2.4MB (5.25") floppies from an IBM 3174 controller (using an 2.4MB floppy drive), and am able to read in 1.2MB floppies using cw2dmk just fine, but it doesn't do so well at processing the (aparently) mixed-density floppy I've been screwing with since yesterday. Using the "testhist" program included with cw2dmk, I can get information about the "unreadable" tracks, but cw2dmk won't process them. I'm trying to make a backup image of a disk so that I'm not screwed when the disk stops being readable... For those interested, it appears that "2.4MB" floppy drives are 96 TPI just like 5.25" DS/HD drives, but they support a higher bit rate. Here's what testhist tells me for a "normal" HD track: mii-300:/usr/src/cw2dmk-3.4# ./testhist 0 0 0 1 2 Reading track 0, side 1... 0: 000000 000000 000000 000000 000000 000000 000000 000000 8: 000000 000000 000000 000000 000000 000000 000003 000001 16: 000008 000005 000002 000005 000012 000006 000010 000479 24: 003590 012073 083091 150788 000112 000013 000004 000004 <snip> peak 0: mean 26.52101, sd 0.67534 peak 1: mean 41.56100, sd 1.04145 peak 2: mean 55.25931, sd 0.90741 drive speed approx 360.943152 RPM MFM data clock approx 510.486128 kHz And for a higher density "2.4MB" track: mii-300:/usr/src/cw2dmk-3.4# ./testhist 0 0 1 1 2 Reading track 1, side 1... 0: 000000 000000 000000 000000 000000 000000 000000 000000 8: 000000 000000 000000 000000 000000 000000 000324 000605 16: 000579 000472 006881 107754 120911 001047 000736 000639 24: 000743 000819 000079 000019 000003 000005 000000 000006 <snip> peak 0: mean 19.51057, sd 0.82054 peak 1: mean 33.65562, sd 1.27275 peak 2: mean 48.29739, sd 0.48487 drive speed approx 374.227723 RPM MFM data clock approx 653.668108 kHz I don't care so much about being able to interpret the data that's there as much as just being able to make a duplicate of the disk which is acceptable to the 3174 controller when this disk bites the dust. Pat -- Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

21 years, 2 months

1
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$2000 Black Apple (?) - scam ?

by cb＠mythtech.net

>He's left me on his mailing list, and since than has reported that he had >an offer for $500, then $1000, and this morning he says he has an offer for >$2000. I corresponded with him again and he says: >>ok right now got offer for 2000 from people in uk. have 2 different people >>in uk that want it for good money. > >This seems completely ludicrous to me --- I know B&H Apples are considered >desirable by some, but $2000 (and shipping from US->UK)!!! There is on on eBay right now, known working, although not with black drives (but with a working Apple II drive, there are two black B&H drives also available for $20 each in another auction). $355 with 15 bids and 20 hours remaining. The pics aren't loading for me, but the description says it is near mint condition. I could see it getting up to $500 before it closes, but $2000... I'd be surprised. The $150 price he asked was probably a good price (I'd have likely taken him up on that price). But whether he really has $2000 offers vs he is just claiming that to make you feel bad for passing on $150 deal (and possibly hoping you are an ignorant collector who will suddenly think the thing is worth thousands and offer him $2500 for it). But who knows, there has been some insane prices on things recently. -chris <http://www.mythtech.net>

21 years, 2 months

1
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Sun 2/120 keyboard and mouse?

by julesrichardsonuk＠yahoo.co.uk

Unearthed a Sun 2/120 yesterday (CPU cabinet plus disk cabinet plus mono screen) but unfortunately no sign of a keyboard or mouse. Anyone know if a later Sun keyboard and mouse can be wired via an adapter to work? We've got a couple of Sun 3 keyboards & mice kicking around which would be enough to test the machine out at least. Both the keyboard and mouse connectors on the Sun 2 are 6-pin RJ45-style connectors (they're probably not called RJ45 in this case as they're smaller, but you get the idea). Actually, I have a feeling that the mouse on our Sun 3/50 uses the same connector (where it plus into the back of the keyboard) so that might be the exact right part. The keyboard on the 3/50's a DB15 though... cheers Jules

21 years, 2 months

4
5
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MS Word 2.0 GE edition manual

by birs23＠zeelandnet.nl

Anyone interested in a user guide for Microsoft Word 2.0 specially made for GE (General Electric) ? Its basically a normal manual with 848 pages but with a GE cover and the text "GE Business Use Only" on it. Stefan. ------------------------------------------------------- http://www.oldcomputercollection.com

21 years, 2 months

1
0
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Difference between M8728 & M8750

by edward＠groenenberg.net

Hi All, Anybody able to tell me the difference between the M8728 (11/70 MOS memory board) and the M8750 (11/750 MOS Memory board) or why DEC decided to assign 2 numbers to it (the M8750 has this number stamped on the handle, but the board bears the number M8728!) Thanks, Ed -- edward at groenenberg.net | Collector of PDP-11's. http://www.groenenberg.net Unix Lives! M$ Windows is crap. '05 GSX-R1000

21 years, 2 months

2
1
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Looking for NeXT system software

by shirsch＠adelphia.net

I have just come into possession of a NextStation, unfortunately sans media. Can anyone point me to where I can get iso images or CDs for this beast? It's got NextStep 3.3 installed, but it would be nice to have a means for recovery. Also looking for the development environment and/or docs. Thanks for any tips! Steve

21 years, 2 months

3
3
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RRD40 troubleshooting

by waisun.chia＠gmail.com

Awhile back I was looking for a caddy for my RRD40, but the ones I found and received (thanks Joe) weren't for the RRD40 but for RRD42. RRD40 takes a weird plastic-only caddy that looks like a pair of pincers, precariously pinching a CD at the edges...(anybody who'd like a pic can email me offlist). Anyway, my RRD40 I discovered unfortunately was nonfunctional *sigh* :-{ The caddy with VMS7.1 was jammed inside and I had to strip the drive down to the internal unit to extricate the caddy and CD. There doesn't seem to be an EJECT button for the RRD40???? So after I've extricated the caddy/CD by raising the motor/spindle clamp manual, I discovered I cannot insert/load the caddy/CD with raising the spindle clamp. Of course I could only do that with a topless unit... I could only conclude that the load/eject mechanism is kaput.... Any clues anybody? Or time to look for another RRD40.... /wai-sun p.s. I had hopes for the RRD40 to be a boot device for my u/VAXen...

21 years, 2 months

2
2
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HP9915B with PSU problems

by vp＠cs.drexel.edu

Yipppeeee! The 9915B now works. My remaining worry is that I do not know why! After removing things to allow me to check them in isolation and then putting them back, I started providing power to the different parts of the PSU. First the +12V supply worked, then the -5V and -12V supplies worked, then the +6V, and finally the +5V. Every time I expected the fuse to blow, but it didn't. So now the whole thing works fine. The 9915A still does not work, but I have found that C45 (the thin tall 390uF capacitor connected to pin 4 of transformer T2 via diode CR12) is shorted. That removes power to the V+ supply taking out the +6V and the +5V supplies. Now all I need is a replacement for C45 and I am in business. Many many thanks Tony. BTW the first time I looked at the 9915 motherboard I freaked out, because the PSU is all over the place. In some cases analog components are located right next to the digital logic. But with Tony's help and his schematics, I managed to map my way around the board. Now when I look at some part on the underside, I know which components are on the other side. Like an adventure game that you have played many times and have the layout in your mind. Real fun. **vp

21 years, 2 months

3
2
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Light pens?

by trixter＠oldskool.org

I have two IBM Model 5150s (one original rev, and a rev b). I think I've explored every single inch of the hardware except for light pens -- I would really like to experiment with one and write some software that interfaces with one. Does anyone know: 1. What light pens were available and for which PCs? (I also own Tandy 1000s, and they have "light pen" ports too) 2. Does anyone have any light pens for sale or trade? I've already tried googling and searching usenet -- the only references I can find are companies selling light pens for modern machines, and tech info that states the obvious (ie. "The IBM PC supported a light pen"... yeah, thanks :-) -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Want to help an ambitious games project? http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/

21 years, 2 months

18
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Macintosh System 7 recreation

by vcf＠siconic.com

Done completely in Flash. Pretty damn amazing: http://myoldmac.net/webse-e.htm -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

21 years, 2 months

1
0
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USB Universal Floppy Disk controller

by dwight.elvey＠amd.com

>From: "woodelf" <bfranchuk at jetnet.ab.ca> > >Dwight K. Elvey wrote: > >>Hi >> I've always been looking at using a DSP chip for this job. >>I did expect to read parts of a track at a time and then >>reassemble them as condensed data. Chips like the Analog >>Devices 2181 have some 80Kbytes of onboard RAM. Although, >>it can't all be used for storage at the same time and >>some is needed for program space. These chips can be >>implemented with a real minimum of outside circuits. >>they even have a serial SPI that can be used to read >>disk data at higher speeds. These processor run at 30 MIPs >>plus. They can run some operations, such as data moving >>to arrays in single cycles, including updating of pointers. >>They can do as many as 5 operations in a single cycle. >> The can bootstrap from simple slowspeed EPROM of FLASH. >>One could easily connect one of these to that USB chip >>that someone pointer to earlier. >>Dwight >> >> >> >Look what you are doing is building a generic floppy disk controler. >The only high speed device what you use to sync the data/clock pulses >to the system cpu clock. The rest is software. I'd sooner use a CPLD >designed for generic bit sampling but a PIC would also work with >a digital data/clock seperator. Now would getting the people who do >cat-weasel create a USB version be a better goal? >Ben alias woodelf >PS. What about hard-sectored floppy disks, that too may need reading >too? Hi I think you are missing what I am saying. The SPI is just a shift register that takes an external clock. It can be programmed to automatically DMA transfer into memory. It is the perfect zero additional logic circuit to use. You don't need to build a data/clock separator or anything. Just sample the data. One could even make the output SPI provide write data. These chips are designed to load their programs from a single flash or EPROM so the entire hardware requirement is almost nothing. I see others on comp.os.cpm talk about using a 50MHz variant of a Z80. I think most miss the point. These DSP's are 30 MIPS+ not just 50 MHz clocks. They have enormous capabilities in a relatively small package. It was like they were designed for this project. You don't need to create a CPLD since the hardware part is already done for you. Dwight

21 years, 2 months

14
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Friden 130 cover removal

by william.layer＠comcast.net

Maybe a little OT, but.. I just laid hands on a Friden EC-130 calculator, and I'll be darned if I can figure out how to take the top cover off of it. The cover *seems* to come off by sliding forward, but there are a pair of pins in the rear that keep it in place. I've tried to flex the cover enough to clear the pins, but the resistance encountered is more than I am comfortable with. How does this thing come off? -- --------------------------------------------- -. William W. Layer .- -. St. Paul, MN USA .- --------------------------------------------------- -. Cheif bottlewasher, Atma-Sphere Music Systems .- -. http://www.atma-sphere.com .- --------------------------------

21 years, 2 months

2
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PDP 11/45 partial success.

by jim＠g1jbg.co.uk

Hi All, after a few days frustration, I have got a little further with my 11/45. The power supplies checked out OK with respect to ripple and output, but a couple have them have the odd VERY fast spike on them - is this normal? (I'm using a 100MHz 'scope - I suspect they may not be visible on a slower one). After reducing the machine to its basics, I found I could load an address >from the front panel, but not write or examine any location successfully. The address and data lines became active, but the processor then goes into a pause state. I found that the MSYN line was not being asserted, and it appears that one ic on the Unibus controller (M8106) is not providing the correct ouput - grounding the scope probe will force the line, and the processor completes its bus cycle (Yes the inputs to the ic are correct!). I have found a spare serviceable UBC, so I'll try that when I next get chance, and if that fixexs the fault, I'll repair mine. Jim. Please see our website the " Vintage Communication Pages" at WWW.G1JBG.CO.UK

21 years, 2 months

10
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Sun 2/120 keyboard and mouse?

by pete＠dunnington.u-net.com

On Mar 19 2005, 23:43, Jules Richardson wrote: > We couldn't get it to work with any transceiver we tried (SQE test was > off, FWIW), whether hooked up to a hub or not - it still gave a > complaint about heartbeat at startup and then subsequent "no carrier" > errors (and the "Ethernet jammed" errors). The complaint about "heartbeat" is because the interface is expecting to see the SQE test appear a few bit times after the end of the frame. "Ethernet jammed" might mean it's seeing a continuous jam signal, or at least sees a jam signal when it listens to the wire to see if it can transmit. A jam signal is what a repeater puts on the wire when it detects a collision (and it would see the SQE test signal as a collision). It's an alternating set of 1s and 0s that lasts 96 bit times, as I recall (an ordinary station can also generate a jam signal but not such a long one), and the object of that is to force everything to see a collision and back off. Now it so happens that 96 bit times is also the interframe gap length, so if you have a repeater with a transceiver set to do SQE tests, it sends an SQE test starting a few bit times into the IFG, then generates a jam which will still be there slightly after the end of the IFG, just when the station might be checking for carrier again. Have you got another repeater somewhere with a transceiver on it? Or are you missing a terminator so that the voltage is out of spec and might look like a collision? > As said in a private mail just now though, we'd had this problem with > our PDP 11/84 - on the advice of an ex-DEC chap, it'd only talk to one > of these DEC units rather than any kind of AUI-equipped hub (or a > transceiver). On a whim we tried the same with the Sun, and it seems to > have improved matters. I've had various DEC machines, like my 11/83, attached to both thickwire and thinwire with non-DEC transceivers and never had a problem. I do check the SQE test, though :-) -- Pete Peter Turnbull Network Manager University of York

21 years, 2 months

1
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Light pens?

by ard＠p850ug1.demon.co.uk

> > > > 2. Does anyone have any light pens for sale or trade? > > > > No, but it's not hard to make one if you don't require high resolution. > > There was at least one design in 80-micro for the Tandy 1000. There were > > plenty of designs for the Beeb (most of them use the Honeywell 'Sweet > > Spot' devices). Thoese were not as good as the Torch one I mentioned, but > > they do work. > > There are a couple on ePay at the moment, too. It may be worth mentioning that microcomputer light pens tend to be somewhat interchabeable. They need either +5V, +12V, or both as power, The actual light pen signal is a pulse that occurs when the light pen detects light from the CRT screen, it's almost always TTL level, and the only possible problem here is that it's the wrong polarity, which can be trivially fixed with a 74x04 inverter. If there's a pushbutton switch on the light pen, most likely it just grounds the appropraite wire when pressed. DEC lightpens (at least the one on my GT40) are different. They're just the phototransistor, the amplifier, etc, is inside the display. Microcomputer lightpens tend to put the electronics in the pen or its interface box. -tony

21 years, 2 months

1
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Sun 2/120 keyboard and mouse?

by pete＠dunnington.u-net.com

On Mar 19 2005, 21:32, Jules Richardson wrote: > The Ethernet card may be a source of trouble. It seems to want something > that provides an external heartbeat - we hooked up a DEC hub to get > around that problem, which stopped the "no carrier" messages on the > console. However, it's still throwing up "Ethernet jammed" messages - > and ideas what that's about? Have you got the "SQE Test" turned on on your transceiver? You have to turn it off if you have the transceiver connected to a repeater (which is probably what your DEC hub is). What the SQE test does is send a test signal after every frame, to test the collision detect circuitry, but the repeater will see this as a real collision and will send a jam signal. -- Pete Peter Turnbull Network Manager University of York

21 years, 2 months

2
1
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IBM Filing Assistant ???

by gehrich＠tampabay.rr.com

A friend has a large number of 3-1/2" HD diskettes with IBM Filing Assistant files on them. Does anyone know of a way to open and read those files so that they can be brought in to a current database program or spreadsheet?

21 years, 2 months

2
1
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TU56/TC11 restoration - Power supply question

by GOOI＠oce.nl

Jay wrote: > Yeah, I'll give you a primer on the capacitors on the TU56.... to get > replacements is about $70 each! For the four motor run caps anyways. > > I'll get to refurbing my TU56 "Someday". I hope to bring my TU56 back to life this year too ...! One note on the ### motor capacitors. AFAIK there is a difference between motor *start* caps and *run* caps. If I am wrong I would like to know, else what is the difference? - Henk, PA8PDP.

21 years, 2 months

4
3
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IBM Selectric elements on eBay

by jpl15＠panix.com

$4.99 buy-it-now: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=41816&item=7501668925 6 of 'em... Cheers John

21 years, 2 months

2
2
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Light pens?

by pete＠dunnington.u-net.com

On Mar 19 2005, 11:19, GManuel $GMC$ wrote: > It must be able to somehow. I have used a light pen on a Commodore 64 with a > Graphics Program called Picasso's Revenge and have drawn on the screen with > it even on a completely black background. Not sure how it does it though. It's just a question of sensitivity. The black portions of the screen are rarely quite black, because the electron beam is not quite turned off. Thus a suficciently sensitive lightpen can still detect the spot as it scans past the pen's location. -- Pete Peter Turnbull Network Manager University of York

21 years, 2 months

2
1
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VMEbus help

by rmeenaks＠olf.com

Hi, I finally got a VME Bus for me to start experimenting. I want to connect this to my Ultrasparc 2 using my Performance Tech Sbus-to-VME controller. Unfortunately, I am a total newbie when it comes to VME. I got a VERO-BICC Vme chassis that apparently once held a Force CPU. There are a bunch of connectors on the VME backplane itself. Also, how does one even set up these guys? The chassis has 5 VME slots. I want to use the Performance Tech as the master controlling the VME Bus? and connect 2 (or more) transtech/inmos VME boards.... Thanks, Ram

21 years, 2 months

1
0
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PerSci Docs list

by doc＠mdrconsult.com

Here's a list of the docs that came with the INFO 2000 disk setup, aka PerSci 277 double drive and 1070 disk controller. I know most of this is already available online, but I can scan any of it on request. PERSCI 1070 INTELLIGENT FLOPPY DISK CONTROLLER 12 pg. glossy by Robert A. Stevens Reprint of an article from Sept 1977 /Interface Magazine/ AN ADVANCED DISC-BASED SYSTEM 4 pg. glossy by Michael Busch and Dan Gaines From same magazine issue INFO 2000 DISK SYSTEM 8 pg. sales brochure for Heathkit H8 Digital Group All S-100 Computers PerSci Mass Storage Systems - Specifications 2 pg. glossy PerSci Model 70 Diskette Drive - Specifications " PerSci Model 277 Dual Diskette Drive - Specifications " USERS MANUAL Intelligent Diskette Controller Model 1070 ~40 pg. April, 1978 PRODUCT SPECIFICATIONS Intelligent Diskette Controller Model 1070 22 pg. June, 1977 WESTERN DIGITAL MOS/LSI FD1771 APPLICATION NOTE FLOPPY DISK FORMATTER/CONTROLLER 20 pg. March, 1978 Installation and Maintenance Manual Duak Diskette Drive Model 277 44 pg. July 1977 Logic & Schematic Diagram Diskette Drive Models 270/272/277 31 pg. January, 1978 Product Specification Diskette Drive Model 277 24 pg. January, 1978 Installation and Maintenance Manual Duak Diskette Drive Model 70 Series 39 pg. October 1976 Product Specification Diskette Drive Model 70 24 pg. January 1977 Product Specification Diskette Drive Model 299B 36 pg. not dated USERS MANUAL Dual Density Controller Model 1170 62 pg. March 1980 Doc PerSci, Inc. Product Price List 1 pg. November 18, 1977

21 years, 2 months

1
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KJ Instruments Model 506 Disk Drive Analyzer

by vcf＠siconic.com

I picked up a KJ Instruments Model 506 Disk Drive Analyzer. It's a tester for MFM drives. On the front are the data and power connectors for a standard MFM drive, plus knobs, switches, LED displays, etc. On the back are two DB-25 connectors. Has anyone got a manual by some remote chance? Has anyone ever used one of these? -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

21 years, 2 months

2
1
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a "field guide" for older TI memory boards

by billdeg＠degnanco.com

Ethan, I wrote the post about the TI 9900 processor cards. What are the dimensions of the cards, and how many pins? I have two ram boards that may be similar to yours, perhaps a little older based on the RAM chip numbers you list below (assuming smaller number means older). I have the details of my TI 9900-related stuff on http://vintagecomputer.net/ti/TI-990-101/readme.txt. Here is a URL of pdf links to TI-related hardware http://computer-refuge.org/bitsavers/ti/ and try http://www.mainbyte.com/ti99/ in the event that you have a card originally from an expansion unit for a 99 4/a. If you can read Japanese, this page appears to have some info as well http://www.orchid.co.jp/computer/hardware/parts/tms9900.html Bill >I was going through the basement at my old place today and ran across >some boards that I bought at Dayton a large number of years ago. They >all seem to be RAM boards of one type or another, one marked "24K", >the other "8K w/ECC", loaded with different amounts of TI4060 RAM >chips (approx the same package dimensions as, say, 5101 SRAMs). I >don't have a net connection there at the moment, and I didn't have my >camera with me, or I'd have taken pictures to post, but I thought I'd >start by asking if anyone knows of a repository of TI board pictures >like some of the Qbus field guides that are out there. I could then >do a little browsing to figure out what these are from. >One guess is that these look like what I've been reading about on the >list recently about the TI990(?). They look newer than the boards in >my TI980, and a little larger than those. >I also found what look to be like TI laptop parts - a couple of >daughter cards that seem to be some kind of video controller, and more >of a main board, but without a CPU. >I have no particular use for them except as a source of parts. If >these sound interesting to anyone here, I can do a little more digging >and/or take down part numbers and take pictures. >No CPU or I/O cards, sorry. >-ethan ------------------------------

21 years, 2 months

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itsy bitsy Unix

by spectre＠floodgap.com

Does anyone know a true (not a homebrew hack) multitasking environment that will run in 16K or less, preferably with available source? I was looking at Mini-UNIX for the PDP-11 and that's something similar to what I'm looking for, but I wondered what other alternatives there were. Any architecture will do, but I'm particularly interested in minicomputer architectures for this project (DG, DEC, IBM, etc., would all be appropriate). Thanks for humouring my odd request ^^ -- ---------------------------------- personal: http://www.armory.com/~spectre/ -- Cameron Kaiser, Floodgap Systems Ltd * So. Calif., USA * ckaiser at floodgap.com -- The steady state of disks is full. -- Ken Thompson -------------------------

21 years, 2 months

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Is there a "field guide" for older TI memory boards?

by ethan.dicks＠gmail.com

I was going through the basement at my old place today and ran across some boards that I bought at Dayton a large number of years ago. They all seem to be RAM boards of one type or another, one marked "24K", the other "8K w/ECC", loaded with different amounts of TI4060 RAM chips (approx the same package dimensions as, say, 5101 SRAMs). I don't have a net connection there at the moment, and I didn't have my camera with me, or I'd have taken pictures to post, but I thought I'd start by asking if anyone knows of a repository of TI board pictures like some of the Qbus field guides that are out there. I could then do a little browsing to figure out what these are from. One guess is that these look like what I've been reading about on the list recently about the TI990(?). They look newer than the boards in my TI980, and a little larger than those. I also found what look to be like TI laptop parts - a couple of daughter cards that seem to be some kind of video controller, and more of a main board, but without a CPU. I have no particular use for them except as a source of parts. If these sound interesting to anyone here, I can do a little more digging and/or take down part numbers and take pictures. No CPU or I/O cards, sorry. -ethan

21 years, 2 months

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HP9915B with PSU problems

by vp＠cs.drexel.edu

Thanks Tony for the advice: > Fuse still blows? Remove the diode between pin 6 of T2 and the -12V line > and the diode between pin 4 of T2 and the V+ line (RH side of sheet 1 of > my CPU board schematic). With those lifted, the supply is reduced to a > simple 12V one driving no load. I did so and the fuse held. I meassured the +12V line and it gave me close to 12V (+11.98V). I also reconnected CR13 (the one at pin 6 of T2) and got the -12V and -5V supplies as well. Unfortunately, when connecting the other diode (CR12, pin 4 of T2), the fuse blows. > I'd supsect (a) a short in one of the output regulators _and_ (b) a > problem with the current sense circuit (round U31, LM311). Any ideas on how to debug this? Thanks **vp BTW I have another question related to another 9915 with PSU probs. What would cause the -12V supply to produce only around -5V (i.e. the volatages on either side of the 332 Ohm resistor are around -5V (not equal, but close).

21 years, 2 months

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TU56/TC11 restoration - VARIAC question

by pete＠dunnington.u-net.com

On Mar 18 2005, 10:07, Dwight K. Elvey wrote: > >From: "vrs" <vrs at msn.com> > >There, "run" caps are generally oil, and "start" caps are > >generally electrolytic. The exception being the occasional "start/run" cap, > >whatever that is. > > I believe that refers to how it is used. During the start, > it is connected to a high current coil but during run, is > is connected to a high resistant one to create phase shift. > > >The original caps in the TU56 are high capacitance, and clearly > >electrolytic. But they appear to be wired for continuous phase shifting > >duty. Hence some of the people on the list insisting that they are "run" > >caps, and that the beefier, more expensive "run" cap should be used. > > Most likely to make the motor run smoother, as though there > were more phases to the AC. Simplified explanation: In "capacitor-start, capacitor-run" motors, which run from single-phase AC, there are two sets of coils. The coils need to be fed with AC out of phase with each other to cause the motor to rotate. The AC supply is fed directly to one set of coils, and through the capacitors to produce the phase shift for the second set of coils. To start the motor, you need lots of current and a big phase shift, so the "start" capacitor in parallel with the "run" capacitor is a high value. A centrifugal switch in the motor disconnects that once it gets to some fraction of its nominal speed, and then only the "run" capacitor is left in series with the second set of coils. Capacitors passing AC have an impedance, analagous to resistance but frequency dependant, so they dissipate energy proportional to their impedance and the square of the current. The "start" capacitor is only in circuit for a short time, so it doesn't need to be as robust as the "run" capacitor, which will be dissipating energy all the time the motor is running. Of course if the load on the motor is low, so is the current, so the capacitors may not need to handle too much energy once it's running normally. -- Pete Peter Turnbull Network Manager University of York

21 years, 2 months

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itsy bitsy Unix

by dwight.elvey＠amd.com

>From: "Huw Davies" <huw.davies at kerberos.davies.net.au> ---snip--- > >Are the risks in preemptive scheduling just ones of complexity? I guess >that it is much harder to "prove" that this type of scheduler is going >to to the right thing at the right time. I know that, >for example, the scheduler for VMS has gone from a couple of pages of >assembler >to something like 75 pages of BLISS! >> Hi Huw I think it is more about predictability. Large preemptive systems can lock up in unpredictable ways. They are hard to confirm as operating correctly under all conditions since the number of permutations of conditions is so large. This makes them dangerous for critical systems. Most non-preemptive system are easier to find bugs because they tend to fail right away if there is such a flaw. Also, preemptive taskers often have to save greater amounts of information since they may break a task at in opportune points. For a general purpose OS, preemptive makes sense. For RTOS is really doesn't. As an example of simplicity, for an embedded machine, I used a non-preemptive tasker to run 50 pid controls, a keypad, paper printer log and a LCD display. This was all easily handled with a single 2MHz Z80. Dwight

21 years, 2 months

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TU56/TC11 restoration - VARIAC question

by dwight.elvey＠amd.com

>From: "vrs" <vrs at msn.com> ---snip--- > >What you are saying is consistent with what I see on most sites selling >these things. There, "run" caps are generally oil, and "start" caps are >generally electrolytic. The exception being the occasional "start/run" cap, >whatever that is. I believe that refers to how it is used. During the start, it is connected to a high current coil but during run, is is connected to a high resistant one to create phase shift. > >The original caps in the TU56 are high capacitance, and clearly >electrolytic. But they appear to be wired for continuous phase shifting >duty. Hence some of the people on the list insisting that they are "run" >caps, and that the beefier, more expensive "run" cap should be used. Most likely to make the motor run smoother, as though there were more phases to the AC. ---snip--- Dwight

21 years, 2 months

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RS/6000 drive questions

by Saquinn624＠aol.com

Does anyone have a discription of how drives are mounted in a 7012/7030 RS/6k with the 2 front accessible 5-1/4 bays? (not the case with the card-edge connector for narrow SCSI) I think I need some type of sled or cage, but I don't know how it attaches or the IBM lingo for it (so Google doesn't work). - Scott Quinn

21 years, 2 months

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Xerox 820 documentation.

by dwight.elvey＠amd.com

>From: "Giuseppe Sarno" <gsarno at nortel.com> > >Hi I own an Old Xerox 820 machine, >Can anyone help to find documentation for it ? >Also is there a way to download programs onto it using the serial/parallel >port ? > >I have seen some info at >http://www.classiccmp.org/pipermail/cctech/2002-September/002642.html ><http://www.classiccmp.org/pipermail/cctech/2002-September/002642.html> but >I couldn't find more. > >Thanks. > Hi You didn't mention if you have a disk that boots and has PIP under CP/M on it. If you do, you can transfer information as ASCII like a BASIC source program or even transfer .COM files by first converting them to .HEX files and then using DDT on the 820 to move them to .COM files. If you are attempting to bootstrap with no disk, you'll have to check with others. One may be able to do it if it has a built in debug monitor. Of course, on can always write some of ones own code and replace one of the internal EPROMs. It is not as impossible as it sounds. You just have to explore a little. Dwight

21 years, 2 months

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looking for R3010

by Saquinn624＠aol.com

Does anyone on the list have a spare R3010 FPU that they would be willing to sell or swap for? please contact off-list -Scott Quinn

21 years, 2 months

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itsy bitsy Unix

by dwight.elvey＠amd.com

>From: "Eric Smith" <eric at brouhaha.com> > >Paul wrote: >> all too often, priorities >> are used to hide the fact that the builder didn't analyze the job >> sufficiently, and simply hacked the priorities until things seemed to >> work in test. > >True. You wouldn't believe how many times I've seen other engineers >trying to set the priority of their task higher than those of other >tasks just because they have some vague idea that their task is >"important", rather than any understanding of actual relationships between >the tasks. > >A good rule of thumb is that in the absence of a rational basis for >one task having a higher priority than another, all tasks should have >the same priority. Far too often a person's intuitive idea of what >the relative task priorities should be is wrong. > >Eric > > Hi If it is important enough to need immediate attention, it should be interrupt driven and not a general task. Many confuse interrupts with tasks. I suspect this is mostly because most preemptive systems use the interrupts to switch task( not very efficient in a RTOS ). Even in a non-preemptive, one can have some priority. Management of the task queue can give similar effects. Dwight

21 years, 2 months

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VMS/RSX tape backup problem

by trash3＠splab.cas.neu.edu

Hi everyone, Well, I am finally getting around to trying to recover some 26 9-track tapes I have been holding on to for at least 10 years. Some are closer to 25 years. I found out six of them had no data, and a bunch more I have been able to read and decode, including some RT-11 tapes and some VAX SIG tapes. Sorry this monologue won't make much sense to you non-DEC folks, but you might have ideas on converting from 800 to 1600 BPI anyway. Here is my dilemna. I have 6 tapes that look like they are 800 BPI, and were most likely written on an RSX-11 system. I have no 800 BPI setup, and if I did, it would be on a VAX, which may not be able to restore the savesets anyway. That is because I have a few more tapes that I can read (or at least dump) but I cannot unpack the savesets. It would appear that the tapes were written in the early days of VMS when the backup and restore utilities were really RSX-11 BCK/RST derivitives, and the current BACKUP program does not recognize the container file as a valid saveset. The label on the front of several tapes date them early 80's and talks about BCK format. The dump sort of looks like BCK stuff. The blocksize is 2064. I've had a couple of offers to try to recover the data, but I was checking to see if anybody was set up to easily read and recover the data, without a lot of reconfiguration or hassle. I'm open to suggestions. I suspect if I knew the layout of a BCK container/saveset I could unpack them myself (except for the 800 BPI stuff). Any ideas?? I also have an XXDP tape, labeled MSDP, which makes me think it is bootable. It would be nice to duplicate it, as it is not easily read to disk. The first block is 14 bytes, and the rest look like 512 bytes. And finally, I have a tape that is readable, is mountable under VMS and I can copy nearly everything off of. That is, the 400+ files up to the file that is marked HECK.BCK. That file is 2064 byte blocks, which makes me think it is also a BCK/RST format. Can't figure how I got it on the end of the tape and haven't figured out how to get it back. Cheers, Joe Heck

21 years, 2 months

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Pornscope. (fwd)

by tomj＠wps.com

It's not-quite-on-topic but it's a well-developed evolutionary dead-end; a platypus display. It *could* be done on old gear... >From Tim Pozar: Vector drawings on an o'scope using a sound card on a computer.... http://www.sensi.org/~svo/pr0nscope/

21 years, 2 months

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Byte sizes (was Re: 2.8M 3.5' floppy (was: three and a quarter loppy?)

by bqt＠Update.UU.SE

On Mon, 14 Mar 2005 Bj?rn <bv at norbionics.com> wrote: > On Sun, 13 Mar 2005 20:36:58 +0100, Eric Smith <eric at brouhaha.com> wrote: > >> Ethan writes about bytes on the PDP-10: >>> On the -10, >>> one stores 6 6-bit characters in a machine word, and one speaks of >>> bytes that are 6 bits. >> >> Not necessarily. On the PDP-10, the byte size could be anywhere from >> zero (really!) to 36 bits. Seven bits was the most commonly used for >> general ASCII text, with one leftover bit per word. In fact, this >> was so common that the KS10 CPU has special dedicated hardware to make >> the 7-bit byte case more efficient than the other supported byte sizes. > ... > > A byte is the smallest INDIVIDUALLY addressable unit of data on a system. Nonsense! Where did you get that? The PDP-10 is an excellent example of when this isn't true. The smallest addressable unit is a word, which is 36 bits. A byte is, as noted, anything between 0 and 36 bits. Bytes are stored in a word, as many as can be fitted. To access bytes on a PDP-10, you have a byte pointer, which consist of a word address, and a bit pointer, and byte size. So it points to the correct word, and then you have a bitfield in that word that a nice instruction can extract, and also move the bitfield pointer ahead the correct amount and move on the the next word, if the next byte would not fit in this word. A byte is simply a convenient number of bits enough to store a character. No explicit definition of how many "convenient" is, nor what character set we're talking about with "character". A byte is just that. A convenient size typ for character data. The fact that people today seem to believe that byte addressable is the only possible thing, along with a byte being 8 bits, is plain and simply because they haven't seen any other. > It was usual to speak of a character when a part of a whole word was > extracted. I do not remember any details of the Univac 1107 (I only > programmed in FORTRAN and Simula on it), but I think the normal character > was six bits. I am fairly certain that was not a byte, it was extracted > from an 18-bit halfword or a 36-bit word. A byte is something you can load > and store to an individual address, and the hardware takes care of the > rest. A character needs some software or firmware mapping in order to read > or write just one of them. Bah. A sixbit character can very well be a byte, it's just a question of if you choose to call it that. Byte addressable is not usable as a definition of a byte. Johnny Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at update.uu.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

21 years, 2 months

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Pornscope. (fwd)

by James＠jdfogg.com

> It's not-quite-on-topic but it's a well-developed > evolutionary dead-end; a platypus display. It *could* be done > on old gear... > > >From Tim Pozar: > > Vector drawings on an o'scope using a sound card on a computer.... > > http://www.sensi.org/~svo/pr0nscope/ WAY too much time on their hands :-)

21 years, 2 months

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LK401

by stimpy.u.idiot＠gmail.com

Quoth Paul Koning (i think), regarding LK401 some weeks back: >Then again, if it's a stuck key or something like that, the keyboard >is beyond repair. LK201 keyboards are cheesy low quality membrane >switches that cannot be disassembled or cleaned or repaired. If >moisture ever gets in them, your only option is to scrap the board. I >found this out the hard way. Does the same apply to LK401 keyboards? I have one with a non-functioning key (try resetting passwords on VMS when you can't get a 'Z'....), and the melted-post construction seems the same. Am I best just looking for a replacement and if so, anyone in the UK got a spare I can make an offer for? Be nice to the moderators and contact me off-list :) Cheers, Pete -- Pete Edwards "Prediction is very difficult, especially if it's about the future" - Niels Bohr

21 years, 2 months

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Media Longitevity/Care

by dwight.elvey＠amd.com

>From: Saquinn624 at aol.com > >Coming in on this a little bit late, but if you haven't checked out the >Library of Congress you should. >www.loc.gov/preserv gives you a basic run down of ways to care for archived >materials, and the NIST/CLIR puts out Special Publication 500-252 "Care and >Handling of CDs and DVDs - A Guide for Librarians and Archivists" (e-version >available). Other tips- gold disks, AZO dye are reputed to last longer. >The phenomenon of failure from the outside in has interesting possibilities- >have software write a known pattern in the outermost section of the disc and >pop up a warning when it starts to deteriorate. Hopefully this would give >enough time to move data to another disk. > >- Scott Quinn > Hi This does require regular reading of the archived disk. This is not necessarily an easy thing to do. Dwight

21 years, 2 months

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FPGAs was USB Universal Floppy Disk controller

by swtpc6800＠comcast.net

Eric wrote: > However, I don't *really* think you want to spend the rest of your > life writing your own FPGA development software. It's a hard problem > and there are hundreds of thousands of man-years of development effort > in the Xilinx software. By the time you got your own software working > for one family, that family would have long since been discontinued. Scott wrote: > I would suspect that while there might be hundreds of thousands of man > hours, that there just can't possible be hundreds of thousands of man > *years* involved. Xilinx is putting in hundreds of man years this year alone. They have been at it for over 20 years so their development software amounts to 1000s of man years of work. (I was in the PLD/FPGA software development business >from 1982 to 1997.) >From the Xilinx Web page http://www.xilinx.com/company/press/grounder.htm Headquartered in San Jose, California, Xilinx is a publicly traded company (NASDAQ: XLNX) with approximately 2,600 employees, with nearly half of its engineers dedicated to software development. Michael Holley (Sorry about the last blank message)

21 years, 2 months

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D.G. Nova/4 on ePay

by tomj＠wps.com

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5173766870& It's quite overpriced, probably times 5 or times 10. I kindly and tactfully wrote to the seller explaining this, but of course I'll lack credibility with them. The seller ("gold-snipper") is a recycler in Portland OR, maybe someone could contact them and go visit? If they're bothering to list on eBay, that's a good sign. They know it might have some value other than by-weight. Who knows what else they have up there. There's a tape and an SMD interface, alarm/clock, and a lot of memory. I'd be interested in a memory card, maybe a basic IO, on the faint chance someone visits them, and gets a bargain on the whole box, and wants to part it out. Clearly it was chopped from some ssytem, there appears to be no cables etc. While it's missing peripherals, if someone could scrounge up a disk or floppy system it would be a decent 1970's-era mini. There's no shortage of software for it.

21 years, 2 months

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Virtual TU56 restoration project?

by wacarder＠usit.net

Is anyone interested in helping me do the TU56/TC11 restoration as a "virtual restoration project"? I know you California guys can get together in person and meet and work on your PDP-1 restoration. I'm stuck here in South Carolina and don't have a face-to-face group to interact with. I'm going to add a projects page to my site, and add the TU56 project under that. I've taken some pictures of it the way it is today, which is pretty much how it arrived, except that I've located a couple cards that were missing. I don't know if anyone has ever done anything like this remotely in a "virtual mode" before, but the idea of a team project sounds interesting to me. David in New York could restore his TU56 in parallel. In my current job I work daily with a team in India. We never see one another face-to-face except when an occasional developer comes to the U.S. to spend some time learning our procedures and processes. We are able to accomplish our goals with teams working on opposite sides of the globe. Several folks have already privately been in correspondence with me and have already been a big help. You know who you are. If anyone's interested, let me know. The project would have a plan that folks could help me put together, to do things in a reasonable and logical order. Things like clean the backplanes, check the flip-chips, re-form the capacitors, etc. I don't know what would be in it for everyone else, other than to know that you helped when it finally spins up a DECtape and can read and write to it as the unit is connected to one of my PDP-11s. Call me crazy if you wish. I suppose I've been involved in too many group projects over the past 20 years and this seems like a fun opportunity to try out the group/team concept in a different way. Ashley

21 years, 2 months

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