35
votes
Accepted
How much slower was the 286 in protected mode?
Basically, anything that involves changing segments is slower, sometimes significantly so; this is unsurprising since descriptors have to be checked, privilege levels potentially changed etc. Other ...
- 117k
22
votes
Accepted
Was any DRAM ever slower than 2 MHz?
From the 1975 Intel Data Catalog entry for the 1103:
one sees that a write or read/write cycle is specified as a minimum of 580 nsec. This corresponds to a speed of 1.724 MHz.
- 915
21
votes
Was the ZX Spectrum used for serious number crunching?
An application I remember because I found the idea very appealing, though I never owned a Specci and so never used the program: A layout program for printed circuit boards with an automatic router.
It ...
- 1,054
18
votes
Was the ZX Spectrum used for serious number crunching?
Number crunching? Beyond spreadsheets and some small custom simulation programs, I doubt anyone used the Spectrum for that. In the 80s if you wanted to do heavy number crunching you at least bought ...
- 13.4k
16
votes
Accepted
What did it cost the 8086 to support unaligned access?
The Missing Angle
It feels a bit like the question misses the most important point about the whole 8086 project over discussing implementation details:
8080/85 compatibility
The 8086 was intended as a ...
- 208k
10
votes
Was the ZX Spectrum used for serious number crunching?
I’ve personally seen ZX81 used as a prototyping platform for an eye tracker running at 100-200Hz sample rate. The aluminized paper printer was used to print out the tracings. Horizontal lines were ...
8
votes
Relay computer performance
Well, a good datapoint here may be the Zuse Z3 and Z4 computers. Not at least as their workings are close related to today's computers in being tact controlled as well as using binary floating point ...
- 208k
6
votes
When did CMOS processors become the fastest?
In DEC, the VAX 9000, due to ship in around 1989 but actually delayed somewhat, was a hugely-expensive ECL-based computer.
By 1988 it had become clear to some that the NVAX processor, a CMOS ...
- 32.5k
5
votes
What made some 8-bit BASIC interpreters especially slow?
I'll add my $0.02 since I've written a few performant BASIC-like interpreters for work for the S08, ColdFire and ARM7TDMI. Everything below is generally NOT what BASIC interpreters did in the 80's.
...
- 311
3
votes
When did CMOS processors become the fastest?
It's hard to put an exact date on it, but the release of the Intel Pentium Pro in 1995 is a good approximation. This was fabricated in Bipolar CMOS (BICMOS) which is now mostly used for mixed analogue-...
- 11.4k
3
votes
Was the ZX Spectrum used for serious number crunching?
Yes, I know someone who used them to solve matrixes and small-scale linear programming problems. It was quicker than traveling to the computer centre and unlike Apple (etc.), they come under the ...
- 409
2
votes
Why was the 1541 so slow?
An important thing to recognize is that at any given time the drive can either be communicating with the C64 or receiving data from the drive head. For each 254 bytes of data received during the ...
- 34.1k
2
votes
What made some 8-bit BASIC interpreters especially slow?
I will add the special case of TI-99/4A TI-basic which is probably one of the worst offender in the category of slow interpreters.
TI-Basic (and also TI-Extended Basic) are especially slow because ...
- 3,189
1
vote
What made some 8-bit BASIC interpreters especially slow?
There are many things that could slow an interpreter to death, I can list them but here are a few:
How it does manages the variables in memory - if the access method is fast or slow, and the number ...
- 693
1
vote
Why was the 1541 so slow?
Much of the slowness had to do with the decoding. There are now various fast loaders that take advantage of undocumented opcodes and other 6502 hacks. With the drives, you could not reliably have more ...
- 21
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