test-drb March 2005

test-drb@ccmp.vtda.org

291 participants
840 discussions

Start a nNew thread

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

19 years, 3 months

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

19 years, 3 months

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

19 years, 3 months

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

19 years, 4 months

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 ]

19 years, 4 months

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 ------------------------------

19 years, 4 months

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 -------------------------

19 years, 4 months

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

19 years, 4 months

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).

19 years, 4 months

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

19 years, 4 months

← Newer
1
...
23
24
25
26
27
28
29
...
84
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 March 2005