test-drb April 2010

test-drb@ccmp.vtda.org

172 participants
242 discussions

chips (was Re: Reading ancient paper digital media (was Re: HamurabiFocal source))

by melamy＠earthlink.net

now that you mention IBM used the word "chips" then the rest of the industry would have to call it something else... They probably even copyrighted the name "chips" and good thing they didn't sue the TV guys when CHiPs was on TV. -----Original Message----- >From: Al Kossow <aek at bitsavers.org> >Sent: Apr 5, 2010 9:49 AM >To: General Discussion at null, On-Topic and Off-Topic Posts <cctalk at classiccmp.org>, null at null >Subject: Re: chips (was Re: Reading ancient paper digital media (was Re: HamurabiFocal source)) > >On 4/5/10 1:07 AM, Rod Smallwood wrote: > >> >> As to punched cards I never heard the rectangular punchings referred to as >> 'chips' on either side of the Atlantic. >> > >I refer you, then, to most IBM punched card documentation on bitsavers. > >http://bitsavers.org/pdf/ibm/cardProc/22-8485-3_operGuide_Sep56.pdf >page 13, for example: > >"Chip Box > Slightly to the right of the machine, as you look at it from the rear, > is a removable box, which is the receptacle for the punching chips as > they are cut out. This box can be easily removed, when necessary, by > lifting a catch that locks it into position. The chip box should be > removed and emptied daily." > >

14 years

Making Hard Sector Floppies

by marvin＠west.net

I just finished a project using stepper motors and a PIC processor to drive the whole thing. Aside from defining the parameters (and debugging my mistakes), it was pretty easy to do. I used a Ramsey Stepper Motor driver kit to drive a 200 step/rev floppy disk drive motor along with a 16F84A PIC processor to control it, and it worked great. Using a sharpie to just mark the hole location sounds like it would be really easy to do. Anyone know the permissible hole tolerances on hard sector floppies? If using a laser, what power would be required to cut the holes and what kind of laser? I currently have a 35W IR laser that could be more than a bit dangerous without proper safety precautions ... I've kind of gotten used to eyesight :)! >> People have been known to make their own 5 1/4" hard-sectored disks. I don't >> > remember the details, but the basic idea was to take a 5 1/4" disk drive to >> > hold the disk, make an index wheel for the holes, add a hole punch, and then >> > just add time. > > One thought I had was to take an old 5.25" floppy frame (say an > SA400), replace the DC motor with a stepper, mount a floppy disc, then > drive the rotation so many steps (you'd have to calculate/measure the > pulley ratio), then punch the media. Simple stepper drivers are > inexpensive to buy ($20, say) or make and easy to drive from a > microcontroller or parallel port (or even 555, if you wanted to do it > "old school"). It'd be even "better" to have a laser make the hole, > but that's a lot of power to be squirting around - punches for mylar > rarely make holes in someone's retina. > > If it's too tricky to mount the punch or die in the floppy frame, one > could pulse the media around as required and dot the spot with a > sharpie, then eject the floppy and punch the holes by hand. > > -ethan

14 years

Executing of RT-11 programs under RSTS/E

by jhfinedp3k＠compsys.to

I thought it would be better to wait until Sunday, April 4th since this request for help would otherwise be seen as an April fools joke. YES! I agree that only hobby users might be interested enough to want these changes, let alone use them. But it keeps me busy and challenged. I have almost finished making changes to MACRO.SAV to fix some bugs and display the year in four digits (1972 -> 2099). Along the way, I found that MACRO.SAV and CREF.SAV assume that each other are on the SY: device and .Chain back and forth when a cross-reference table is added to the listing. Now both MACRO.SAV and CREF.SAV are allowed to be on a device different from SY: and from each other if the user so specifies. All of the code has a simple solution under RT-11 and I presume there may be a simple solution when run under RSTS/E. However, I have not run any code under RSTS/E for 20 years and have no simple way of setting up a system. My preference would be to run RSTS/E under SIMH with: (a) Debug capability if possible (b) No debug capability, but just run the program (c) Have someone else run the program under RSTS/E and test it for me in that order of priority. Has anyone a simple RSTS/E image that I can download and run without modification to allow me to test the programs myself under SIMH? That should keep everything legal for an RSTS/E distribution that is allowed under SIMH. I would also need a few hints on running, but probably very few. Can anyone help? John Dundas has helped by providing a PDF of a manual describing the RT-11 emulation under RSTS/E. This manual provides some details of the RT-11 .Chain EMT request when used under the RT-11 Real Time emulation under RSTS/E, but there are conflicts with the documentation on the RT-11 side of the fence as to the use of the PPN from RSTS/E during an RT-11 .Chain EMT request. In particular, for some of the RT-11 documentation, the 5th word in the Chain Area starting at octal address 500 (i.e. at octal location 510) is the RSTS/E PPN value for the file to be .ChainED to while other definitions place a very different value at octal location 510. Does anyone have an idea as to which documentation is correct? There may be some RSTS/E images at trailing edge. However, I would appreciate something that is ready out of the can, so to speak, as my focus is so narrow. Using RSTS/E is far from my goal. I just want to have the modified MACRO.SAV and CREF.SAV pair work under RSTS/E as well as RT-11, RTEM and TSX-Plus. The manual It may also be useful to test under any other RT-11 emulator. I know of just one, but I can't remember who developed it. Jerome Fine

14 years

PIC900C

by ard＠p850ug1.demon.co.uk

I am looking for a data sheet (or at least a pinout) for an IC numbered PIC900C. Despite the number, this is not a microcontroller, it's some kind of power driver IC -- from the 'house code' on it, I suspect it's little more than a transistor array, here [1] configured as a full-H driver foo a motor. FWIW it's in a 'wide' 18 pin DIL package with a metal top surface to attach to a heatsink. I beleive it was made by Unitrode in the early 1980s. Alas the only Unitrode data book I could find on the web was too early for it. [1] On the 'servo' (notor control) board of an HP9144 tape drive. -tony

14 years

PIC900C

by melamy＠earthlink.net

I will have to do some digging on this. I used a PIC625 from Unitrode in designing a 12 to 5 volt switching regulator. It is a switch mode transistor with a flyback diode in it if I remember correctly. The device is a four pin can (smaller than a TO3 case). Just not sure if the 900 was in the same family. best regards, Steve Thatcher -----Original Message----- >From: Tony Duell <ard at p850ug1.demon.co.uk> >Sent: Apr 3, 2010 12:06 PM >To: cctalk at classiccmp.org >Subject: PIC900C > >I am looking for a data sheet (or at least a pinout) for an IC numbered >PIC900C. Despite the number, this is not a microcontroller, it's some >kind of power driver IC -- from the 'house code' on it, I suspect it's >little more than a transistor array, here [1] configured as a full-H driver >foo a motor. FWIW it's in a 'wide' 18 pin DIL package with a metal top >surface to attach to a heatsink. > >I beleive it was made by Unitrode in the early 1980s. Alas the only >Unitrode data book I could find on the web was too early for it. > >[1] On the 'servo' (notor control) board of an HP9144 tape drive. > >-tony >

14 years

RE: Reading ancient paper digital media (was Re: Hamurabi Focal source)

by dm561＠torfree.net

----------------Original Message: Date: Thu, 01 Apr 2010 08:02:31 -0700 From: "Chuck Guzis" <cclist at sydex.com> Subject: RE: Reading ancient paper digital media (was Re: Hamurabi Focal source) On 1 Apr 2010 at 0:17, Ian King wrote: > Interestingly, the idea of a timing mechanism hosted on the medium > itself never occurred to Herman Hollerith or his successors, which I > guess speaks to their confidence in their engineering. Not necessarily. If you look at Hollerith's card reader, it read the entire card in parallel, using spring-loaded probes that would extend through the card holes and touch a pool of mercury. No need for clocking. Serial card reading came later when the card was not manually read. If you're going to automate card transport, then reading the card serially actually is easier. What was the proportion of readers that read colum-serial versus row- serial? I believe the CDC 415 punch had its read station as 80 brushes, reading the card just punched row-wise. --Chuck --------------------Reply: As a matter of fact reading the card 'sideways' was a basic principle of the electro-mechanical punched card systems that (along with card sales) were IBM's bread and butter until the mid-sixties. With the exception of keypunches, paper tape converters etc. these machines were 'clocked' through the 12 states (12,11,0-9); the (firmly clamped) cards and various gears, relays, punches, type bars, etc. were cycled through these 12 states in synchronized parallel unison, much like most of the manual 'posting machines' with full row and column keyboards that preceded and coexisted with them. Timing diagrams looked much like the diagrams we're familiar with, but they were usually calibrated in degrees of rotation of the master camshaft instead of time. Interesting to compare not only the architectures of then vs. now, but the overall systems; a room full of various machines would be more or less the equivalent of a fairly simple micro, each machine (and operator in some cases) would be a programming algorithm or an IC, the data path would be an actual real well-worn path where cards would be carried from one machine to the next in the processing sequence, patch boards would be EPROMs, etc. etc. The hardware and documentation may be preserved, but I suspect the design of the actual application systems, i.e. 'programs' where procedures are in fact different physical machines, is becoming a lost art.

14 years

Don't Copy That Floppy

by marvin＠west.net

Ah yes, I still have one of their "Don't Copy That Floppy" posters and I *think* the VHS tape that was part of that campaign. Must be worth millions by now :). > The SPA ran their "Don't Copy That Floppy" campaign well into the mid- > to-late 90s. Did anyone ever *really* pay $100K for owning a single > illegal copy of "Where in the World is Carmen Sandiego" as their ads > claimed? > > --Chuck >

14 years

Tons of 'free' TI-99/4A stuff in Helena, Montana

by tosteve＠yahoo.com

Kaye wrote to me: "As well as software and docs, there's TI magazines, monitors, computers, peripheral memory boxes and cards, joysticks, printers, etc.." None of it is terribly valuable - there are no TI-99/4 (non-A) systems. It's all free if picked-up in person - it's too much work to mail. e-mail her at kaye67 at bresnan.net if interested.

14 years

Reading ancient paper digital media (was Re: Hamurabi Focal source)

by roger.holmes＠microspot.co.uk

> From: M H Stein <dm561 at torfree.net> > From: "Chuck Guzis" <cclist at sydex.com> > > As a matter of fact reading the card 'sideways' was a basic principle > of the electro-mechanical punched card systems that (along with > card sales) were IBM's bread and butter until the mid-sixties. > > With the exception of keypunches, paper tape converters etc. these > machines were 'clocked' through the 12 states (12,11,0-9); the (firmly > clamped) cards and various gears, relays, punches, type bars, etc. > were cycled through these 12 states in synchronized parallel unison, > much like most of the manual 'posting machines' with full row and > column keyboards that preceded and coexisted with them. > > Timing diagrams looked much like the diagrams we're familiar with, > but they were usually calibrated in degrees of rotation of the master > camshaft instead of time. The punch of my ICT1301 is an IBM design, originally built under licence by BTM (British Tabulating Machine co), which merged to form ICT. It clocks through the 12 states and a few more while the card is being fed. It mechanically pauses in the middle of each state by means of a Geneva mechanism. It has two camshafts with bakelite cams which operate contacts which controls the punch and signals the CPU when data is ready to be punched and check read. When one card is being punched the previous card is at the check reading station with 80 wire brush contacts. It does indeed have a timing diagram as you describe. The main mechanism sits on a steel casting, and I'm told its the top part of an original Holerith design which had integral cast ball and claw feet. This plate is mounted on rubber bushes to a massive angle iron frame with the widest bit of copper earth braid I've ever seen. It operates at 100 cards per minute and the CPU has to feed it 80 bits of data for each row and reads 80 bits back from the previous card. Yes the interface is 80 bit parallel in each direction plus lots of control and status signals, 200 wires in total (8 cables of 25 cores each). The manual tells programmers to avoid punching more than 60 columns in any row. How any programmer was supposed to avoid punching a card full of zeroes I don't know. I have punched fully laced cards with it no problem, and I have a complete spare mechanism anyway, which I'm thinking of linking to my Mac, though its a big project. I've never been told that the card reader or line printer have any connection with IBM but I suppose it is possible. The reader is 600 cards a minute (80 column first) and the printer is a 600 lines per minute, 120 column drum printer (all the similar characters aligned not staggered) with a sprag mechanism which advances the paper. The card reader has a reject hopper and a main stacker. The main stacker turns the card around a big rubber drum and feeds it into slots in a pair or rollers which then turn and flip it out under the stack of cards already read. Roger Holmes

14 years

AP: MITS Altair pioneer dies age 68

by c.murray.mccullough＠gmail.com

It's my understanding that Ed Roberts was indeed instrumental in bringing the microcomputer to the masses or at that time(mid-70's) to the cognoscenti. His Altair 8800 was covered by technical magazines since 1972 or thereabouts. The Micro-soft empire owes its existence to MITS. Some would say that Mr. Roberts never gained or received the recognition due or deserved. Yet as far as this reader can determine he never sought it and his devotion to medicine and patients in later years speaks volumes in a world obsessed with 15 minutes of fame. Vain-glory seems not to have been part of his character. Murray--

14 years

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test-drb April 2010