test-drb March 2007

test-drb@ccmp.vtda.org

239 participants
488 discussions

Creating an 8-inch floppy from 3.5-inch Teledisk image

by g-wright＠att.net

-------------- Original message from "Glen Slick" <glen.slick at gmail.com>: -------------- > On 3/23/07, Richard Lynch wrote: > > > > I ran into this file a few years back and wasn't able to do much with it. I > > later created my own Altos floppy images using both Teledisk and Imagedisk. > > I'll send them to you offlist for you to try out. > > Richard Lynch > > > > I have an ACS8000-7 dual floppy and an ASC8000-10 floppy / hard drive. > > On both of them I get the monitor prompt to insert a floppy for > autoboot (the -10 fails the hard drive boot first). I tried creating > floppies from ACSBTMD1.IMD and DIAG26K.IMD and I don't get any > indication that anything is happening on either system with either > floppy. No additional output on the terminal and it doesn't appear > that the floppy is seeking at all. > > I don't know for certain that the floppy drives are actually working > on either system other than the motors running. I got them as-is a > couple of years ago with no boot floppies and no way to create boot > floppies at the time. > > I suppose I could pull the drives and attach them to the PC I used to > write the floppies and see if I can read the floppies back ok. That > sounds too much work like work instead of fun for this evening. > > -Glen Glen I have both of theses and you should hear the drives load and unload the heads. . One of the problems I have is the head (nut and screw) assembly stick and the head never gets back to track 0. I have also had to replace the floppy disk controller chip in my 8000/2 in the past These use different boot disks. I have both if you need another sorce. No too sure what is in the ZIP file. - Jerry

18 years, 1 month

IBM PS/2 Models 25 and 30

by ddsnyder＠zoominternet.net

To all who replied, good point, when offering a machine, state the processor manufacturer, number and speed. I'll eventually develope a system... Model 30 is an Intel (AMD) 80286 at 10Mhz Model 25 is an Intel (NEC) 8086 at 8MHz Dan @ Butler, PA

18 years, 1 month

Byte magazine back issues

by jwstephens＠msm.umr.edu

are the byte magazines available online anywhere, including scans of advertisements? I am interested in some ACP ads, but don't know when they were placed. anyone with a collection I would appreciate finding the full page rear cover inside or outside ads, and getting a high res scan. thanks Jim

18 years, 1 month

John Backus passes away...

by roger.holmes＠microspot.co.uk

>>> 100 FORMAT( HX)=(1+BX ) >>> >>> Recall, that prior to FORTRAN 90, FORTRAN had no reserved words. >> >> Yes that does look weird at first sight. > > The bigger problem is that it's absolutely ambiguous in the light of > CDC FTN syntax. It can legitimately mean either a FORMAT statement > with the Hollerith constant ")=)1+B" or an assignment to the HX-th > element of an array called FORMAT of the value obtained by evaluating > 1+BX. The PTR ended up on the "deferred" list for quite a long time > as no one could think of an adequately airtight fix. Lots of work- > arounds were proposed, such as "well, if the statement number is > referenced in an I/O statement, then it's a FORMAT" or "if there's an > array called FORMAT, then it's an assignment". Unfortunately, > FORTRAN doesn't demand that FORMAT statements be referenced by an I/O > statement--"orphans" are perfectly legal. It was a real puzzle. Thanks for that, I had completely missed what you were saying, though I still don't know what a PTR is, except for a Paper Tape Reader or an abbreviation for PoinTeR. A bug report? If a FORMAT statement is not referenced by a READ or WRITE statement, does it matter if it is compiled incorrectly? Anyway, if they wanted an assign 1+BX, why put it in parentheses? Still an interesting example though. > Smart*ss customers! > > The usual way for FORTRAN compilers to work back then was to look at > the first word of a statement and attempt to parse it accordingly. > If that failed, then the statement was deemed to be an expression and > re-parsed. I presume that's why some Basics needed LET before an assignment. > This is only one case where a vendor's language extension got it into > trouble. Early on, most language standard specifications called out > the minimum subset of the language that had to be implemented and > remained silent on vendor extensions. Hence, you got scads of > differing dialects all claiming to be "FORTRAN IV". To my knowledge, > this persists in BASIC more than in any other language, ANSI X3.113 > nothwithstanding. Human languages are far worse of course. Roger.

18 years, 1 month

Long Paper Tape (renamed)

by roger.holmes＠microspot.co.uk

> From: woodelf <bfranchuk at jetnet.ab.ca> > >> Later on we moved the compiler onto a GEC 4080 to cross compile >> for the >> 920. The 920 program grew and I had to modify the compiler so it >> could >> produce the binary output in chunks as it exceeded a 1000 foot >> roll of >> tape, and anyway I was the only person in the office capable of >> rolling >> up a full 1000 foot roll without damaging it. > > I am guessing you get 8 characters per inch of tape. > That is a 93.75 K of data per tape. Ten characters per inch, so 120KB. Useful content though was one 18 bit word per three characters, so 40K words. The 920ATC had 128K words of program/data storage plus another 128K for data only. So if every instruction was used, that's 3 full reels of tape and possibly more if there were any pre-loaded tables in the data only section. The reason it was difficult to wind up was our paper tape winders only had a 6 of 7 inch back plate, so beyond that I had to use two fingers to guide both sides of the tape, and got hard skin on both fingers. It became such a problem the company bought Penny & Giles 1/4 inch cassette tape machines. They worked fine for a while then the baud rate started drifting as it was derived from an RC network! Eventually our engineers modified them to use a proper oscillator circuit. In the mean time I had hooked up a direct serial link between the 4080 and the 920ATC running at 9600 baud. My first comms program (well, sort of). Roger.

18 years, 1 month

Hmm -

by sdc695＠yahoo.com

On Thu, 22 Mar 2007 19:20:51 -0700, "Chuck Guzis" <cclist at sydex.com> wrote: > On 22 Mar 2007 at 14:59, Steve Wilson wrote: > > > >4900796 (Somebody will understand this reference) > > > > Someone is trying to boot Fortran off of the Disk on an IBM 1620 me thinks... > > Isn't 00796 where all-well-behaved programs went to die? I.e. reload > Monitor (sort of a CALL EXIT)? > > --Chuck We have a winner. Just to add to the trivia, to boot the disk you needed a few more characters: 3400032007013600032007024902402111963611300102 Which if you were on a model 2, you needed to make sure that indirect addressing was turned on (nothing worked right if you didn't!). After doing that a few times, you remembered it pretty well. OB Fortran reference: There were several "load & go" Fortrans available for the 1620. The one I liked the best was Witran. It fit into a 20k machine, but was interpreted. Still not too bad for a Fortran. The best was the Monitor II Fortran II. It generated automatic floating point instructions, and used index registers (only for the compiler I think). Pretty speedy. The hardware floating point on a 1620-II was faster than the software on the (next generation) IBM 1130 (I used that too). The 1620's bonus was that standard precision (in floating point) was 8 significant digits. If you really felt ambitious, you could go MUCH higher (28 digits with Fortran-II). Few machines today can match that in hardware! -- Tom Watson tsw at johana.com ____________________________________________________________________________________ Get your own web address. Have a HUGE year through Yahoo! Small Business. http://smallbusiness.yahoo.com/domains/?p=BESTDEAL

18 years, 1 month

John Backus passes away...

by Billy.Pettit＠wdc.com

* Al Kossow wrote: > I wonder which machine would take the prize for the > most done with so little? In the 60's, probably the LINC 1 or 2k 12 bit words, LINCtape, typewriter, CRT, and Lab I/O http://www.mit.edu:8001/people/ijs/epl/LINC.html Billy: It touched me as a little ironic that the photo attached said: JPEG image, 20k Linc could so much with 1 or 2K, and today we need 20K just for a simple photo of it. Billy

18 years, 1 month

John Backus passes away...

by ken＠seefried.com

From: Sridhar Ayengar <ploopster at gmail.com> >Jules Richardson wrote: >> > I wonder which machine would take the prize for the >> > most done with so little? > >I would have guessed something with plugboards for programming. >Possibly drum-memory. > Bletchley Bomb and/or Colossus? Certainly the results to resources ratio was pretty amazingly high.

18 years, 1 month

One last comment on Burroughs and crossbar switches

by aek＠bitsavers.org

A little more digging, and the crossbar in the B 5000 series idea came from the D 825 SAGE backup system AN/GSA-51 ref. Burroughs B 5000 conference Sep 85, archived by CBI (page 18) other references can be found on line to the D 825 being the first multiprocessor, and to the memory/processor switch http://www.cs.uiowa.edu/~jones/arch/notes/35cross.html http://www.fas.org/nuke/guide/usa/airdef/buic.htm http://www.cc.gatech.edu/gvu/people/randy.carpenter/folklore/v3n1.html

18 years, 1 month

Can the MicroVAX II or KDJ11-A boot off of a SCSI CD-ROM?

by dbetz＠xlisper.com

It seems all of my removable media devices are broken (TK50 and RX50). That leaves me wondering if I can boot a MicroVAX II or a KDJ11-A off of a CD-ROM. I have a SCSI controller that should work with either machine and I have a SCSI CD-ROM drive. Can either of these machines boot from a SCSI CD-ROM? Thanks, David

18 years, 1 month

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test-drb March 2007