57
votes
Accepted
What was the first operating system called DOS?
DOS/360
(As distinct from TOS/360, the tape OS)
Announced at the end of 1964 per Wikipedia.
- 33.5k
30
votes
Accepted
Did the IBM ServiceFree really reach 80 MIPS in 1975?
This seems to be a mangled account of the IBM 801. The project was led by John Cocke. This started as a project for a computerised telephone switch, which needed a lot of instructions per second, but ...
- 12.4k
26
votes
Raytheon 704 mini uses?
I might be the only person on StackOverflow who used this machine!
I wrote tens of thousands of lines of Raytheon 704 assembler code in the 1976-1978 timeframe. We used it to run an air traffic ...
- 421
25
votes
Accepted
Did the PDP-8 designers consider a stack?
Without detailed documentation on the PDP-8 design process, we cannot say for sure. I suspect that while they may have briefly considered it, it was never a serious prospect.
The PDP-8 is just the ...
- 13.5k
24
votes
Accepted
Why are old computers so vulnerable to temperature changes and moisture?
If you watch enough YouTube videos of repairing old micros — and even ones that aren't that old (486s didn't come out that long ago, did they?) — you'll see a lot that have suffered some ...
- 1,008
23
votes
Accepted
What was this mini-computer tape troubleshooting process
While I can't be certain, what you describe sounds like some variation on what's mentioned in the description of Techmoan's The Magnetic Tape Viewer - see the sound on a tape:
Q) You can buy these ...
- 6,351
23
votes
Did the IBM ServiceFree really reach 80 MIPS in 1975?
John Dallman already showed the 801 being the most likely one referred to. The 801 was indeed the ground breaking work Mr. Cocke was later recognized for. In addition it might be helpful to check the ...
- 213k
20
votes
Accepted
What programming languages were most commonly used on the AS/400 in the 90s?
IBM i is actually the name of an operating system rather than the hardware. So, it is the successor to OS/400 rather than AS/400. The current hardware is IBM Power Systems. These can also run AIX ...
- 2,014
18
votes
History of High Availability in the mainframe and minicomputer eras?
I'm pretty certain the concept of RAS (reliability, availability, serviceability) has been in IBM's mainframe line since very early on. I always found it funny that one of the big selling features of ...
- 4,594
16
votes
Has there ever been a instruction set architecture that did not require instruction decoding at all?
Horizontal Microcode works exactly as you describe - one bit for each possible internal control line (Vertical Microcode saves instruction bits by encoding sets of N mutually-exclusive control lines ...
- 161
15
votes
Floating point performance of classic minicomputers
There are nearly endless benchmarks (see a short list of relevance at Benchmark Programs and Reports on the Top500 site) and it may need a bit of work to understand each benchmark's implications (see ...
- 213k
14
votes
Accepted
When did smart terminals arrive?
It seems to me that a smart terminal would need a microprocessor, so I would expect them to start showing up in the early seventies,
Not really, as discrete, specialized processors could do the job ...
- 213k
14
votes
Uh, oh, I've woken up in 1973. Can I get a job in computing?
Make your way to Palo Alto, California, and find the Xerox PARC facility. Do whatever it takes to get a conversation with Alan Kay. Admittedly, you don't know any Smalltalk, but neither does anybody ...
- 6,118
14
votes
Raytheon 704 mini uses?
According to the Raytheon 704 Technical Manual:
The processor may be used as the control element for data acquisition, data processing, and system control. (p. 1-1, section 1-7)
An example of ...
- 2,706
13
votes
Accepted
How did the Nova 1200 divide so quickly?
Not a complete answer, but a bit of information from the manual (for several Novas including the 1200):
The hardware multiply-divide option for the Nova is actually a peripheral device connected to ...
- 26k
13
votes
Has there ever been a instruction set architecture that did not require instruction decoding at all?
(Preface: The question is a bit misleading, as many of the conditions implied are not well defined. See below)
First candidate: Transport Triggered Architectures
Transport Triggered Architectures ...
- 213k
12
votes
Accepted
Floating point performance of classic minicomputers
The Whetstone table may be useful. The ratio of Whetstones/s to FLOPS varies, but not too much.
A whetstone test outputs a table, like
Loop content Result MFLOPS MOPS ...
- 18.3k
11
votes
Accepted
Reconstruct the loop from "The Story of Mel"
I recently ended up looking into this myself, including reading the programming manuals for both machines mentioned.
Some quirks of the RPC-4000 include that the last few addressable tracks of the ...
- 16.7k
10
votes
Accepted
What did order processing on a teletype look like?
But in between those [Batch vs. Terminal], there was an era of 'interactivity, but not as we know it', when computers supported interactive work by teletype.
Not really.
To start with, these were ...
- 213k
10
votes
Raytheon 704 mini uses?
I was an engineer in the 70s / 80s - expert in PTS100, 706, 704 and RDS500.
I worked for SITA; these machines were used for communications - with multiplexers for modems (2400 baud - 9600 baud) and ...
- 101
9
votes
History of High Availability in the mainframe and minicomputer eras?
Two high availability systems which predate Tandem Computers:
The IBM 9020 (a cluster based on IBM/360 mainframes) was developed for US air traffic control and is described in IBM Systems Journal 1967 ...
- 1,162
8
votes
Indirect addressing using address bits as marker (tagged address)
As another-dave points out, your "indirect bit in the
instruction" versus "indirect bit in the address" distinction can be
ambiguous. When the instruction and the address operand are always
contained ...
- 24.6k
8
votes
History of High Availability in the mainframe and minicomputer eras?
Every Solution Needs a Problem
High Availability is like any other concept only useful in a context that needs such. Here the context is non planned requests at random time - or in other words: Online ...
- 213k
7
votes
Accepted
Typical mid-scale business computer system of the late 70s
In Israel, in the early 1980s (I started work as an accountant in 1982 so I don't know how long the system had been in use prior to this date), all the kibbutzim of an area used to connect to one PDP-...
- 825
7
votes
Has there ever been a instruction set architecture that did not require instruction decoding at all?
The Pilot ACE, commercialized as the English Electric DEUCE, had an instruction set which looks pretty peculiar to modern sensibilities.
It had no explicit 'opcode' field, instead just source and ...
- 33.5k
7
votes
Accepted
Did any core-memory computers have a read-and-erase instruction?
Yes. Sort of.
The KDF9 had an accumulator stack (the 'nesting store' or nest) which was mostly made of fast (1µs read, 1.5µs write) core - the top 3 elements were in fast registers, with 16 words of ...
- 33.5k
7
votes
Did the PDP-8 designers consider a stack?
I'm going to say no.
The PDP-8 was chiefly designed for compatibility with the PDP-5, and this machine also had no hardware stack.
There is not enough room in the instruction space to add push and ...
- 38.2k
6
votes
How many hours of labor did it take to assemble a minicomputer?
Most PDP-series machines of this era were built using a large number of cards (with soldered components) connected by a wire-wrap backplane and a series of cables. I think the cables were mostly used ...
- 16.7k
6
votes
Indirect addressing using address bits as marker (tagged address)
I'm curious how common the style of "indirect addressing via the address value" instruction was at the time?
To avoid a list answer and as an absolute answer isn't possible anyway, let's say "quite". ...
- 213k
6
votes
When did smart terminals arrive?
Arguably the prototypical smart terminal was the IBM 3270. According to this link IBM History the 3270 was first demonstrated on May 23, 1971. While the Intel 4004 was shipping already at that time, ...
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