test-drb January 2008

test-drb@ccmp.vtda.org

221 participants
430 discussions

stuff needs rescue in Pasadena California

by dgriffi＠cs.csubak.edu

20 or so years worth of stuff needs to be gotten rid of NOW in Pasadena California. I can't take this one due to time and space issues. Email me at the below address or my ACM address (my first and last name followed by acm.org). Here are the highlights: * A mostly full set of Byte Magazine. * First and second year of PC Magazine. * An Altair with a homebrewed front panel. * Several PCjr keyboards still in boxes. * An external 8-inch floppy drive. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

17 years, 3 months

OT: science debate

by evan＠snarc.net

http://www.sciencedebate2008.com/www/index.php This is a petition to urge all of the US presidential candidates to have a debate about scientific policy. (Just fyi, since cctalk is NO place for political talk.)

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by ajp166＠bellatlantic.net

> >Subject: Creating new CP/M disks - Progress on IMSAI > From: M H Stein <dm561 at torfree.net> > Date: Sat, 12 Jan 2008 09:14:09 -0500 > To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> > >-----------Original Message: >Date: Fri, 11 Jan 2008 23:50:27 -0500 >From: "Richard A. Cini" <rcini at optonline.net> >Subject: Creating new CP/M disks - Progress on IMSAI > >All: > > I?ve been busy lately rebuilding the floppy system on my IMSAI. I >scrapped the Frugal Floppy 8? in favor of a CompuPro Disk 1 using 5.25? >disks to emulate 8?. This has been a long running project, but with the >assistance from someone on comp.os.cpm who went through the exact same >process with nearly the same hardware, I?ve been able to create a brand new >CP/M 2.2 master disk. Yeah! > > Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb >high-density; no schematic) drives I?m using is that the motor runs all of >the time (just like an 8? drive) but these late-model Teac drives don?t have >head relays, so the heads are engaged all of the time. > > I?m looking for some advice/whatever on engaging the motor when needed. >The Disk 1 is based on an 8272 controller chip and it has a HDL (head_load) >signal which, through jumpers can be made to appear on the *MOTOR signal pin >of the standard IBM floppy disk interface. I tested the HDL signal and it >activates at the right time, so its following the 8? sequence, but the pulse >width leads me to believe that it?s too short to let the motor spin-up and >go ?ready?. Cannot use that as the HLT parameter is soo short for adaquate spinup time. You might get away with it though as the FD55GFRs do spinup fast. The Disk1 Didn't have a direct motor control port like the 1A but it did allow for using the latch used for serial output to be used as a general motor on. Find MotorENA on the schematic. > There is a way to control this with software...and I may go that route >anyway...but has anyone done this sort of thing < used a 5.25? HD drive to >simulate an 8? drive and if so, which drives did you use? The DISK1 serial port if not used as boot console is a 1 bit port that can be controlled with software. It's in the manual, switch S1-3. The manual covers all the things for 5.25" floppies. To do a read or write you set motor enable, wait 1sec then read or write and reset motor enable. To minimize starts and stops a timer of 10seconds or more is desireable. Its the way I'd do it using the DISK1 and have done it with the DISK1A. The disk1A has a differnt specific port for that which is part fo the 1 to 1A differences. Allison > > Any input appreciated. Thanks. > > >Rich > >---------------Reply: >There are several different OEM versions of the FD-55GFR with >various jumper options. > >If yours has one, put a jumper on the ML position and isolate the >/MOTOR ON signal somehow (tape over pin 16). > >You will also have to change the DC jumper to RY in order to get >a proper /READY signal. > >Whether it will ultimately actually work will depend on the controller; >there are more issues with 1.2HD drives than one would expect. > >mike >

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by dm561＠torfree.net

Date: Sat, 12 Jan 2008 09:22:38 -0300 From: "Alexandre Souza" <alexandre-listas at e-secure.com.br> Subject: Re: Creating new CP/M disks - Progress on IMSAI >> I?m looking for some advice/whatever on engaging the motor when needed. > How is DS0 line activated? As far as I know the sequence should be: > - Activate DS0, motor starts to run > - Activate "head load" so the heads can do their job > - Read/write > Since your motor is always on, seems that you have DS0 activated >permanently. Isn't something wired wrong? --------- As a matter of fact, the motor did run constantly on many 8" drives (remember that many had 110V AC motors). m

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by ajp166＠bellatlantic.net

> >Subject: Re: Creating new CP/M disks - Progress on IMSAI > From: "Alexandre Souza" <alexandre-listas at e-secure.com.br> > Date: Sat, 12 Jan 2008 09:22:38 -0300 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >> I?m looking for some advice/whatever on engaging the motor when needed. Forst if you running motor only when needed you need a delay in software for the motor to come up to speed (1 sec does it). > How is DS0 line activated? As far as I know the sequence should be: > > - Activate DS0, motor starts to run > - Activate "head load" so the heads can do their job > - Read/write > > Since your motor is always on, seems that you have DS0 activated >permanently. Isn't something wired wrong? It's possible the connector is upside down. The other is the drive in use has a jumper for motor always on. Also DS0 (thats a zero right?) needs to be selected to read or write to the the zeroth drive. Allison

17 years, 3 months

Creating new CP/M disks - Progress on IMSAI

by dm561＠torfree.net

-----------Original Message: Date: Fri, 11 Jan 2008 23:50:27 -0500 From: "Richard A. Cini" <rcini at optonline.net> Subject: Creating new CP/M disks - Progress on IMSAI All: I?ve been busy lately rebuilding the floppy system on my IMSAI. I scrapped the Frugal Floppy 8? in favor of a CompuPro Disk 1 using 5.25? disks to emulate 8?. This has been a long running project, but with the assistance from someone on comp.os.cpm who went through the exact same process with nearly the same hardware, I?ve been able to create a brand new CP/M 2.2 master disk. Yeah! Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb high-density; no schematic) drives I?m using is that the motor runs all of the time (just like an 8? drive) but these late-model Teac drives don?t have head relays, so the heads are engaged all of the time. I?m looking for some advice/whatever on engaging the motor when needed. The Disk 1 is based on an 8272 controller chip and it has a HDL (head_load) signal which, through jumpers can be made to appear on the *MOTOR signal pin of the standard IBM floppy disk interface. I tested the HDL signal and it activates at the right time, so its following the 8? sequence, but the pulse width leads me to believe that it?s too short to let the motor spin-up and go ?ready?. There is a way to control this with software...and I may go that route anyway...but has anyone done this sort of thing < used a 5.25? HD drive to simulate an 8? drive and if so, which drives did you use? Any input appreciated. Thanks. Rich ---------------Reply: There are several different OEM versions of the FD-55GFR with various jumper options. If yours has one, put a jumper on the ML position and isolate the /MOTOR ON signal somehow (tape over pin 16). You will also have to change the DC jumper to RY in order to get a proper /READY signal. Whether it will ultimately actually work will depend on the controller; there are more issues with 1.2HD drives than one would expect. mike

17 years, 3 months

ST412 controller cables

by peter.hicks＠poggs.co.uk

Hello! In an attempt to resurrect an old Mitsubishi MR535R (RLL) drive, I managed to pick up an ST11M controller by accident - it was advertised on eBay as "MFM or RLL". Two things: 1) Does anyone have a spare set of control and data cables? I'm willing to pay for 'em, or visit Maplin for components to make up a set, since they're probably easy to make with IDC connectors and ribbon cable. 2) Does anyone happen to have a suitable RLL controller they're looking to get rid of, or could let me have access to one for a few hours? The 60Mb drive possibly contains some very old RM Net 3.1 software which I'd like to archive off, as there doesn't seem to be anyone at all - even at RM - who has any software left. I'd be happy to travel (within reason, I'm in London, UK) and exchange use of a controller card for beer/alcohol :) Cheers Peter -- Peter Hicks | e: my.name at poggs.co.uk | g: 0xE7C839F4 | w: www.poggs.com A: Because it destroys the flow of the conversation Q: Why is top-posting bad?

17 years, 3 months

Converting monochrome video signal to VGA monitor?

by markk＠clara.co.uk

Hi, I recently received a Commodore A2024 monitor. This is a 15" monochrome/ grey-scale monitor which has a special converter board inside, that converts the 15kHz video output by an Amiga computer to 31kHz. It also supports a "tiled" mode, whereby Amiga video frames are combined to produce a 1024x800 or 1024x1024 pixel image. Unfortunately the monitor was damaged in transit and the tube is cracked. However the converter board should be usable. I want to make an adaptor to connect the converter board to a standard VGA/multi-sync monitor. Has anyone on the list connected an old workstation (or maybe an Atari ST?) with monochrome output to a modern monitor? Those should be similar. There should be no problem with the horizontal and vertical scan rates. I need to look at the board circuitry, but I'm pretty sure the horizontal and vertical sync signals will be at TTL levels, which is fine for connection to a VGA monitor. The monochrome video signal is output on a phono/RCA socket. Inside the monitor, a coaxial cable goes from that to the PCB at the end of the tube. I need to determine the video signal level. Apparently VGA uses 0.7V p-p, so I might need to add a resistor in-line to reduce the voltage if it's any higher. Unfortunately I don't have access to an oscilloscope. Could I just arrange for a full-screen white image to be shown, measure the voltage using a normal DC multimeter, and multiply up the value shown to account for the proportion of each scanline corresponding to sync/flyback? Once that issue is solved, I should be able to connect the video signal to the green signal pin of a VGA monitor and get a green picture. In order to get a grey-scale picture, can I simply connect the video signal via resistors to each of the R, G and B pins on the monitor connector? If so, what resistor values would be needed? If not, I guess I could use or build a 1-to-3 splitter/amplifier circuit, then connect the 3 outputs of that to the R, G and B lines. -- M

17 years, 3 months

Looking for old issues of Datamation, late 60's with Fairchild/SEL Advertisement

by ragooman＠comcast.net

I'm hoping somebody might have some old issues of Datamation from the late 60's. Somewhere around '68 there was an Ad by Fairchild semiconductor showing a SEL minicomputer. Hopefully I could get the original, or perhaps a scanned copy. I'm trying to locate this for some old friends, we all worked there, they were there from the very beginning. I/we would be grateful for any help. thanks, =Dan

17 years, 3 months

(Someone's idea of) Worst Keyboards

by silent700＠gmail.com

On Jan 11, 2008 10:00 PM, Zane H. Healy <healyzh at aracnet.com> wrote: > same reasons the author gave, ergonomics. But then in the 80's this > kind of thing was normal and none of us gave it a second thought. Yeah, maybe that's the problem I had with it. And I have to give him credit for mentioning the holy Model M as one of the best :)

17 years, 3 months

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test-drb January 2008