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Questions tagged [besm-6]

The BESM-6 was a Soviet computer, designed in the 1960s and in production from 1968 to 1987 in various forms.

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11 votes
2 answers

What is the purpose of the ω register of the БЭСМ-6?

This page describing the БЭСМ-6 instruction set refers to a value called ω, which is stored inside a Mode Register. It appears to be set by certain kinds of instructions, so that ω can tell you which ...
11 votes
6 answers

Was there a Western computer with blatantly missing instructions in the instruction set?

In the BESM-6, there is an instruction (045) to add index registers, but not to subtract them, however, there is a nearby unused opcode 047, which is made synonymous to 045 (in fairness, that's true ...
2 votes
0 answers

What was the hardware-level data format on IBM 1316 or 2316 disk packs?

A description of the hardware-level track format of the IBM media used on the BESM-6 I've found is as follows (translated by Google with minimal corrections): Track header structure: ...
5 votes
0 answers

Did the Soviets need industrial espionage to get IBM software pre-1970?

Due to lack of the OS-level file system on the BESM-6, and to deficiencies of data visualization tools which could help people decide which blocks of a system disk could be reused (the line of ...
3 votes
0 answers

How small a punched card or punched tape batch job could be?

A while ago I read a post about creating the smallest possible ELF executable doing something observable — printing the number 42, for example — which Linux could accept and execute successfuly. The ...
7 votes
1 answer

Was dynamic type check in Pascal commonplace?

The BESM-6 Pascal compiler I'm experimenting with has a notable difference from Standard Pascal: formal arguments of formal parameters-procedures or functions are not specified, but are checked at ...
10 votes
5 answers

Which CPUs had instructions leaving data registers in an unspecified state?

When an ALU performs a floating point division operation using the non-restoring or the SRT algorithm, it maintains the current value of the "remainder" (in quotes, because it is not a true ...
9 votes
1 answer

Is this a bug or an allowed Pascal behavior?

Consider the following Pascal program: 1 1 PROGRAM MAIN(OUTPUT); VAR F:TEXT; I:INTEGER; 2 2 BEGIN 3 2 REWRITE(F); 4 3 FOR I := 10 TO 30 DO BEGIN 5 3 WRITELN( I, ’...
2 votes
0 answers

Has anyone heard of SCHEMA page layout tool?

I've found a text formatting tool, under the name of SCHEMA, which would accept an input language like *RED *0STA*NN*RG*1RL*0MCS1 20 *3/ *MDLorem ipsum dolor sit amet, *MDconsectetur adipiscing elit, *...
10 votes
0 answers

What is the timeline of NASA ground control computers?

In the movie "Hidden Figures", NASA receives an IBM 7090 in 1961. What is the subsequent timeline of the primary computing means for flight planning and orbit calculation? Specifically, what was the ...
8 votes
1 answer

How can floating point addition be so slow on a BESM-6?

In the BESM-6 technical manuals — for example, in the ALU description, page 4 — there is a table specifying min/max/average instruction latencies in clock cycles (the last 3 columns; the ...