Questions tagged [ibm360]
Questions regarding the IBM System/360 computers and their descendants.
9
questions
21
votes
3answers
7k views
What was the rationale behind 32-bit computer architectures?
Though today various power-of-2 word sizes seems to be the norm, back in the 50-60s multiple-of-6 word sizes was more popular and was required by Department of Defense(DOD) in particular.
36-bit ...
20
votes
17answers
4k views
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 ...
5
votes
2answers
214 views
Were there “higher level programming” macro packages for the IBM Macro Assembler?
The IBM/360 Macro Assembly language was quite powerful, allowing non-trivial compile-time string manipulation.
Did macro packages exist which would facilitate programming at a (slightly) higher level, ...
2
votes
1answer
128 views
Any informations on IBM's “Generalized Information System” still available?
I wonder if anyone has documentation left on this topic. In the early 80's, I used to be a 3270 terminal operator, and I wrote programs with GIS. I remember that this language was rather mighty but ...
13
votes
5answers
3k views
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 /...
2
votes
3answers
293 views
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 ...
5
votes
3answers
1k views
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 ...
3
votes
2answers
847 views
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 ...
2
votes
0answers
98 views
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
...
