test-drb August 2005

test-drb@ccmp.vtda.org

227 participants
528 discussions

by jwest＠classiccmp.org

Just wanted to say thanks for the people who have contributed knowledgebase articles to the classiccmp knowledgebase (www.classiccmp.org/kb) I do know that one person here is working on a really good article, should show up there soon! So, who wants to spearhead putting in a short knowledgebase article about hooking HP-IB devices, given the recent discussion :> Jay West

19 years, 5 months

What is GenRad 2293 central station? (related to DEC?)

by vax9000＠gmail.com

I saw a GenRad 2293 central station today. It looks like a computer. It stands with a digital storageworks frig size frame, but I don't know whether they are related. I looked at the back and found various ports, with one labeled "TK 50". Does anybody know what is inside?

19 years, 5 months

FA: DEC H7140AB power supply (PDP-11/44), Cromemco s-100 boards, PC/104 boards

by rigdonj＠cfl.rr.com

Still sorting out the excess <http://search.ebay.com/_W0QQsassZrigdonj>. I'll be posting some PC/104 boards later today and tomorrow. Joe

19 years, 5 months

TG43 signal and the Nec 765 (Jules Richardson)

by herby1620＠yahoo.com

The TG43 signal has NOTHING to do with pre-compensation. The original IBM specification for single density (128 byte per sector, 26 sector per track, 77 tracks) floppies has an option to change the write current on the drive head for the more densely packed sectors on the interior of the disk. because of the constant angular velocity (360 rpm to be exact) the interior tracks were more dense than the outer ones. To prevent the bits from blasting into each other they (IBM) reduced the write current on the inside (greater than 43, thus TG43) of the disk. This was purely a drive option. Some later drives had more smarts and could count track position on their own, and didn't need the signal. Precompensation was NOT used on single density 8 inch drives. When things changed to double density drives (MFM encoding) precompensation was necessary when too many transitions were next to each other. The floppy formatter chip usually did this internally, and since it had the track register, it could do it "automagically". Some did it differently, but it basically shifted the bits a bit to one side or the other to "compensate" for bit crowding. ____________________________________________________ Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs

19 years, 5 months

need to read 8" floppies on pdp8

by trestivo＠concentric.net

I have a semi-urgent need to read some 8" floppies that I believe were created on a pdp8 system. Does anyone have the hardware available or know what I need to find to accomplish this task? How about the i/o card for the pdp8? I have access to an 8" floppy drive that was used on a pdp11 (rx01/rx02). Thanks, Thom Best Regards, Thom Restivo LEWIS AND CLARK 624 Fishtail Palm Blvd. Melbourne, FL 32901 Phone: (321) 537-2384 Fax: (321) 768-0006 Email: <mailto:trestivo at lewis-clark.com> trestivo at lewis-clark.com Web: http://www.lewis-clark.com <outbind://1-0000000093B4C03865156F4391D62644BDA1760CA4652700/exchweb/bi n/redir.asp?URL=http://www.lewis-clark.com>

19 years, 5 months

QuantumLink

by Richard.Cini＠wachovia.com

Is there a Stratus simulator out there? Maybe this is another project someone can work on for SIMH. Rich -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Vintage Computer Festival Sent: Thursday, July 28, 2005 1:43 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: QuantumLink On Thu, 28 Jul 2005, Jeff Davis wrote: > I have some baubles (qlink keychain, install disks); I don't think anyone kept > backup tapes of the server software, since it ran on Stratus minis, not > exactly something people had in their basements. Plus it was company > confidential, etc. Someone somewhere has to have backup tapes laying about. -- 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, 5 months

"New" RL02 on the way - how to power up?

by GOOI＠oce.nl

Charles, VERY IMPORTANT: get the disk pack out of the drive before shipping. You must lock the heads! If the cover is closed, there are 2 ways to open it. 1) apply power. The FAULT light will go on, but what is more important is that the cover latch is unlocked. 2) without power, open the small "cover" at the right side. Now you have mechanical access to the latch. When you have removed the pack, look at the opening in the middle at the rear end (inside the cartridge space). You will see a small square plate that is held by one screw. Turn the screw some 4-5 times. Now you can rotate the square plate 90 degrees. It will cover the opening from which the heads come out. Tighten the screw. Now the heads are locked, and you are safe to ship the drive. Not sure if it is necessary to lock the spindle ... maybe others can shed a light on this issue? Cleaning becomes an issue when you have the drive :~) See www.pdp-11.nl (peripheral -> disk -> RL01/RL02"). gd luck, - Henk, PA8PDP. -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]On Behalf Of charlesmorris at direcway.com Sent: woensdag 27 juli 2005 17:08 To: cctech at classiccmp.org Subject: "New" RL02 on the way - how to power up? I have just purchased an RL02 and while waiting for it to arrive, I am wondering what to do for cleaning and lubrication before power-up. I don't know how long it's been sitting (indoors). I have downloaded the manual from bitsavers. I know there has been some discussion on this list recently but I think that was on the care and feeding of RK05's... Also, the seller tells me he can't get the pack out: >When I had the disk pack cover off, the release handle on the pack did >not release the disks and I did not want to force it. Does the drive >need to be powered on and is there a way to remove them without powering >it on? He does know about the shipping screws and will install them before Fedexing. So, what should I do first? thanks for any assistance. Charles

19 years, 5 months

Serial Configurations (was Devilish Altair Serial ConfigurationProblem)

by ajp166＠bellatlantic.net

> >Subject: Serial Configurations (was Devilish Altair Serial ConfigurationProblem) > From: "Richard A. Cini" <rcini at optonline.net> > Date: Sun, 31 Jul 2005 12:35:05 -0400 > To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> > >All: > > The problems I'm having have to be related to status bits and >device initialization. The board is an SSM 2p+2s which is based on the >TMS6011 (which has lots of equivalent UARTs such as the COM2502, 2017, >TR1402, AY3-1015). The SSM board is very flexible -- I can change status >bit order and polarity to match almost any configuration need. Right now >I have it strapped to match the Altair Revision 1 SIO board (ports 0/1, >RxStat=bit0, TxStat=bit1, active high polarity). I've also tried TxStat >at bit7. That should work. > > Does someone have sample working code for initialization, input >and output? I have a few datasheets but none of them give sample code >sequences. I'm missing something here and I'd appreciate a push. OH, one more detail.. Most of the MITS software when loaded inits based on the front pannel sense switches (IN FFh). The configuration sets the board in use and bits. T he setting are in the MITS software manuals. Allison

19 years, 5 months

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test-drb August 2005