Questions tagged [ibm]
For questions regarding the products of IBM, International Business Machines.
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Why did IBM decide to use 8 bits for EBCDIC?
Why did IBM decide to use 8 bits for EBCDIC?
7 bits per character seems reasonable, since 2^7 = 128 symbols which is enough for all English letters and special symbols.
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IBM vs DEC and business partners
A Quora question Why did Digital Equipment Corporation (DEC) fail? has gathered some really interesting answers, including from former DEC people.
There is one such answer I do not quite understand:
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Record definitions with IBM COBOL and IMS
A common technology stack for line of business applications in the sixties and seventies was IBM COBOL with the IMS database. I'm curious about how the combination handled record definitions.
COBOL ...
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1answer
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Can I restore an S/38 program to a current IBM i?
The IBM System/38 or just S/38 was an IBM mini-computer launched in 1978. I don't know when IBM stopped marketing it but their AS/400 was released in 1988 and it was very easy to switch from the S/38 ...
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Were any IBM mainframes ever run multiuser?
Now of course there is a sense in which they were – some mainframe installations supported thousands of users! But there is a distinction.
Consider the familiar fixture in so many 80s computer science ...
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How was it possible to run IBM mainframe software in emulation on HP?
... At least, without getting sued into the ground?
According to one of the answers to What was the most critical supporting software for COBOL on IBM mainframes?
We installed a new HP replacing an ...
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What was the most critical supporting software for COBOL on IBM mainframes?
Over the past half-century, one of the largest trends in the computer industry has been the replacement of mainframes by microcomputers. Not total by any means – there are still many mainframes in ...
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1answer
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What is the function of this strange IBM apparatus?
Does anyone know what kind of device this is? I found it in my late dad's stuff, probably from the 1970s.
It has no number, type, model, serial number or anything else on it that could be used for ...
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154 views
How plausible is this data corruption on an IBM 9-track tape?
Preamble
For a while, I had a copy of a BESM-6 Pascal compiler which worked only on very simple programs, like "Hello, world", and would throw a division by 0 exception on anything more ...
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What specific factor(s) made Thomas Watson, Jr. (of IBM) so enthusiastic about early electronics?
One of my favourite computer history books is Stan Augarten's "Bit by Bit", which has an author-approved scanned copy at http://ds-wordpress.haverford.edu/bitbybit/
In it, the author makes ...
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6answers
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How much data could be stored on a single punched card?
I was looking at this IBM webpage on the history of floppy disks and it says the original 8-inch floppy disk from 1971 could store 80 KB of data, equivalent to that of 3000 punched cards.
So, based on ...
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1answer
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What is the purpose of the “difference of absolute values” instruction?
The IBM NORC computer, among others, had an arithmetic instruction computing the difference of the absolute values of its operands (|x|-|y|, see NORC Programming Manual, page 11, opcode 28), which ...
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How can I boot or extract files from an IBM PS/1 with a DoubleSpace-compressed hard drive?
I’m trying to boot an old IBM PS/1, mostly with the intention to read out its hard disk. I realized quickly that the original floppy disk drive was broken, so I replaced it with a Gotek floppy ...
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2answers
533 views
What year was my old, long-lost IBM PC born? And which form factor/model was it?
I've spent a ridiculous amount of time and effort over the years just trying to figure out what exact IBM product I grew up with. At last, I've finally established for 100% certain that it was a:
IBM ...
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0answers
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Why was the IBM 7070 unsuccessful?
In a talk on the IBM 360 and the computers it replaced the speaker at 39:35 describes the 7070 as 'a dog', and elsewhere contrasts it unfavorably with the 1401 (which considerably exceeded ...
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Were round punchcard holes mechanically stiffer?
The most common punch card format was the IBM 80 column by 12 row, with narrow rectangular holes. However, there were other possibilities, such as a later IBM format that used round holes. That one ...
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What did code on punch cards do with the other six bits per column?
In the fifties and sixties, program source code was typically stored on punch cards, one card per line.
The most common card format was the IBM 80 column by 12 row. For source code, this was commonly ...
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1answer
203 views
Best way to swap IBM PC case badge?
A while back, I purchased an original IBM PC (5150). The seller had an improper top case or badge on it, as the badge actually said it was an XT (5160) instead. After confirming that it is indeed a ...
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Was this FORTRAN “extension” originated by IBM?
This question has been prompted by a recent question about the assigned GOTO operator.
It appears that some early FORTRAN implementations supported a non-obvious construct: using an indexed variable ...
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When did IBM start to use ASCII?
I’m trying to figure out when IBM switched to ASCII and when ASCII became a worldwide standard.
Moreover, did IBM make ASCII standard worldwide?
What I have found:
According to Wikipedia, IBM System /...
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3answers
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Why did IBM System 360 have byte addressable RAM
According to wiki IBM System 360 had byte addressable RAM.
Previously IBM had machine with word addressable memory.
Did they make a switch for comparability between different machines?
Or it was just ...
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Why did IBM System /360 have byte addressable RAM, but didn't have 8 bits registers
According to wiki IBM System /360 had only 32 and 64-bits registers for data.
I'm wondering if they used 8-bits symbol it means that they stored it in a 32-bits register.
Did they have any performance ...
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2answers
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Why was the maximum byte size of 8 bits on IBM 7030?
As far as I know, IBM 7030 used term byte. But this byte was just an imaginary term to make easier for our brain to work with bits. So it had nothing in common with a physical realization of the CPU.
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2answers
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Why did IBM 7030 or IBM 360 use byte and word addressing simultaneously
In 1950s machines had a 36 bit words. And in this word we could pack symbols using 6 bits. And to fetch this symbols from the word programmer should do it using bit manipulations.
In 1961 IBM released ...
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1answer
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Was the IBM S/360 Responsible for Popularizating the 'A'-to-'F' Notation in Hexadecimal Numbers?
In the early history of computing before the mid-1960s, there wasn't an universal, de-facto standard for the written representation of a hexadecimal number, different computer systems used their own ...
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1answer
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Is the “IBM standard character set manual” around?
From Wikipedia's code page article:
Originally, the code page numbers referred to the page numbers in the IBM standard character set manual
Is any version of this publication available? I'd be ...
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1answer
364 views
Why did IBM develop 5250 block mode terminals when 3270 already existed?
IBM introduced the 3270 family of block mode terminals in 1971, for use with IBM mainframes (System/370 and successors). Then, in 1977, IBM introduced the 5250 family of block mode terminals for use ...
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2answers
901 views
When was DEFUN added to Lisp?
I don't see DEFUN in a ~1966 copy of PDP-6 LISP. I do see it in a 1972 Maclisp.
AI memo 116A from 1967 doesn't have DEFUN. (It does have MACRO.)
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Thinkpad 380E keeps shutting down randomly [closed]
Recently, I got a 380E from ebay. Seller says that it has boot error and not working, but the error was typical 161/163. I've replaced nee BIOS battery, and error was gone.
After that, I formatted ...
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0answers
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When and with which system or software was IBM's system of tape headers (VOLx, HDRx, …) introduced?
Background:
IBM compatible tape structure (*1) consists of a series of label blocks describing the volume and each file (Data Set). Essential the structure looks like this:
VOL1..9 Volume header
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2answers
344 views
Using generic SMPS adaptor on old IBM Thinkpad makes strange symptoms
I found abandoned IBM Thinkpad 560X inside of company's cabinet. So, I got curious and get generic AC-DC SMPS adapter for 10$. It was rated 16V 3.75A, diameter for plug is just right, and polarity was ...
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Are there statements from IBM insiders revealing why OS/2 was dropped?
In the early to mid-90s I was an OS/2 user and supporter. The operating system was originally jointly developed by both Microsoft and IBM. Both companies claimed it was the future, including public ...
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IBM PS/2 Model 56 486 SLC2 Faceplate replacement
I'm trying to track down a replacement faceplate for an IBM PS/2 Model 56. Mine was broken during shipping. Anybody have any ideas where I could find one?
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Why were index register contents on IBM 7090 subtracted in forming the effective address?
On IBM 709/7090/7094 mainframes, the effective address of an instruction could be modified by the contents of an index register specified in the instruction encoding.
That much is a fairly standard ...
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Did any 360-compatible machine implement registers in core?
In the early days of transistors, when they cost on the order of a dollar each, it was possible to implement CPU registers with magnetic cores (the technology used for main memory at the time) instead ...
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How did IBM's “Mag Card” drive and magnetic media work?
In the 1970's IBM popularized an early word processing solution using their popular Selectric typewriter line and something called "Mag Card". This video demonstrates the system in operation.
The ...
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Was there a clearly identifiable “first computer” to use or demonstrate the use of virtual memory?
The NPR.org news article and podcast How The World Has Changed! Science During The 40 Years Of 'Morning Edition' includes the photo below with the caption
Before the introduction of the personal ...
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1answer
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Power switch color on IBM PS/2 red vs white?
Why do some IBM PS/2's have a red switch, while others have a white switch?
Does the red or white power switch on the power supply signify something about the model number, CPU, or options that the ...
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1answer
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Looking for an IBM multimedia demo from the 80s about “Ulysses”
I am trying to identify / find an online copy of a multimedia technology demonstration video. Timeframe: late 1980s? Source: IBM. Format: VHS.
The content of this video was a computer program with a ...
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IBM terminal schematics
I'm searching for the electronics schematics for IBM terminals 3477 and 3486. I've already googled for it without success. I've to mend this hw and the power side seems ok but doesn't function, so I ...
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Replacing cord for IBM model M keyboard
I bought a model m keyboard for use at work. The keyboard functions fine, but the cord is in bad shape. Functionally, the cord does not cause any shorts, but the plastic is very brittle and large ...
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IBM mainframe classic executable file formats
Most modern platforms have pretty well-defined file formats; e.g. Windows uses PE, Linux and BSD - ELF (previously a.out), macOS - Mach-O, AIX - XCOFF and so on.
What were (are?) common executable ...
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Did the IBM PC use the 8088's NMI line?
As I understand it, the Intel 8088 CPU used in the original IBM PC had two interrupt lines: INTR and NMI. INTR was fed from the Intel 8259 Programmable Interrupt Controller, which handled the IRQs ...
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1answer
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The IBM RAM with non-standard pin layout
One and half decade ago I had an black IBM Thinkcentre tower. The specs were:
Pentium 4 2.66 GHz
256 Mb IBM RAM (which later got upgraded into 512 Mb RAM),
40GB HDD,
XP Pro SP3,
GeForce 2 MX 400.
...
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Why wasn't EBCDIC designed with contiguous alphanumeric characters?
Inspired by this question on ASCII, I have wondered similar things about EBCDIC.
At work we have an EBCDIC file that gets sent to a mainframe (I presume an IBM one) and to view it on my laptop I ...
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Desk computer with embedded CRT, 8" floppy
Back in 1981, my high school's computer classes were something like Computer Programming I and II, which taught BASIC on the Apple ][+, and a Computer Programming III class.
In the III class, a ...
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Compaq Portable vs IBM 5155 Portable PC
In 1983, Compaq introduced its first product, a portable computer weighing 28 pounds; 128-640K RAM, two 5.25" floppy drives, 9" monochrome CRT for $3590. It was extremely successful in the market, and ...
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What is the purpose of the yellow wired panels on the IBM 360 Model 20?
I just finished reading a story about an IBM 360 Model 20 rescue, and some of the pictures caught my eye.
Specifically this one:
Searching online, led me to several more pictures, all with ...
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XT IDE causes BASIC not to load properly on IBM 5155
I recently picked up an XT IDE. It works fine for the most part, but when I tried to load BASIC samples from the original IBM DOS 1.1 floppy(I was booting from it), the system hung up, only showing a ...
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IBM 650 - how many logic gates?
How many logic gates did the IBM 650 have? I'm used to measuring the complexity of a CPU by transistor count, but the 650 was a vacuum tube machine; the number of tubes would also be an interesting ...
