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1500 questions
28
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5 answers
DIY Project using 1970s 8-bit CPU, is it possible?
I've recently really wanted to try and design a computer system around a retro 8-bit CPU such as the Zilog Z80 or the Intel 8080, and I would appreciate some sanity checks! I was inspired by Ben Eater's series on making a breadboard CPU, and I've…
Zee2
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How to get started writing C for the IBM PC in 1980-81
Suppose it's late 1980 to early 1981, you've got some software you want to write for the IBM PC which will be released later in 1981, want to get started ASAP, and believe C is the right language for the job. However, a C compiler on the PC does not…
rwallace
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28
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5 answers
How did the Atari 2600 achieve a resolution of 160 x 192 pixels with only 128 bytes of memory?
According to wikipedia, the Atari 2600 had a resolution of 160 x 192 pixels.
Had it been monochrome, it would had needed 160*192 = 30,720 bits of video RAM, or 3,840 bytes.
But the total memory was 128 BYTES.
How did it manage to reach that…
vakvakvak
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4 answers
What was the legal arrangement between author, publisher and end user for 'type-in programs' in old computer magazines?
Today we live in a world where the idea of open-source is well understood and protected by legal gobbledygook like the MIT, GPL, LGPL, Apache, and EI-EI-O licenses. (Ok, I made up that last one). It isn't sketchy to grab source code created by…
Geo...
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28
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Is there any advantage of a ceramic microprocessor over a plastic one?
Looking at this page which refers to the initial release of the Z80 microprocessor, it prices the ceramic one at $65 versus the plastic version at $59.
I know that at least with the 6502, the earliest run was ceramic and now considered quite…
bjb
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28
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3 answers
Why was MacOS unix certified?
As I understand it most Linux distros adhere to the UNIX specifications while only a few actually get UNIX certified. If plenty of Linux distros can happily adhere to the standard without being certified in it, what then motivated Apple to get MacOS…
Neil Meyer
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28
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8 answers
Why was desktop CPU frequency so low in the late 1990s?
I think even in the 1990s it wouldn't have been a problem to build a 4GHz clock generator.
Increase a transistor here and a resistor there and the clock rate will go up.
(I know there was DECT in the early 1990s and it had a frequency of 1900MHz in…
zomega
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28
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2 answers
How could the SNES take advantage of in-cartridge coprocessors that weren't invented when the SNES came out?
The SNES had a number of "enhancement chips" that were available in the cartridges. These chips did lots of different things. How did these chips actually transfer data to the SNES? How did the SNES use chips that weren't available at the time of…
Michael Stachowsky
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5 answers
Why does the FAT file system have separate ‘hidden’ and ‘system’ attributes?
File systems used by DOS and Windows have used file attribute bits as a relatively prominent feature. The first of them, FAT, exposes four attributes to the user: read-only, archive, hidden and system. (There are a few more used internally, but…
user3840170
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8 answers
Why did x86 support self-modifying code in the 80s and 90s?
In this question, by 'self-modifying code', I mean software that writes to a section of code that the CPU will very soon fetch and attempt to execute.
I am not here talking about the software engineering implications of self-modifying code, or about…
rwallace
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28
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9 answers
Fastest 8-bit microprocessor for multiply-accumulate?
I'm wanting to identify which 8-bit microprocessor would have the best performance for a multiply-accumulate operation.
By "operation", I mean the minimal implementation for 16-bit operands and 32-bit result in assembly language.
By "8-bit…
Brian H
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28
votes
3 answers
The two types of Return keys on keyboard layouts
Why have these two types of Return keys persisted to this day? A quick look at different keyboards from different keyboard manufacturers from today shows the Shift-style Return seems to have more presence. What is the history behind these two…
raspi
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28
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13 answers
BYTE Magazine outside the U.S
BYTE magazine was a well-known computer periodical published in the U.S. that had a successful run from the late-1970s to the 1990s. As such, it was not only a regular fixture on U.S. newsstands, but was rather distinguished from the competition. It…
Brian H
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28
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10 answers
Limiting factor on early color palettes
Early color computers typically had a limit of X colors used simultaneously from a palette of Y, a classic example being the Commodore 64 which could do 320x200 monochrome or 160x200 four colors, chosen from a palette of sixteen.
The limitation on…
rwallace
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28
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14 answers
Were people building CPUs out of TTL logic prior to the 4004, 8080 and the 6800?
I've just finished reading Charles Petzold's book, Code: The Hidden Language of Computer Hardware and Software. In it Charles explains building relays into gates, gates into logic components, and logic components into computing machines.
He talks…
hawkeye
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