All Questions
5,690
questions
438
votes
8
answers
230k
views
Why did moving the mouse cursor cause Windows 95 to run more quickly?
I was playing Hypnospace Outlaw, a game about a retro-themed OS. This OS has a peculiar behavior that when loading a webpage, wiggling the mouse cursor will load the page faster.
That reminded me of ...
- 2,000
182
votes
4
answers
45k
views
What algorithm did Microsoft use to dither colour in early versions of Windows?
In the late 1980s to mid 1990s, most consumer-class video hardware was not capable of displaying greater than 16 colours at a time. To create the illusion of greater colour, software often "blended" ...
- 2,857
165
votes
1
answer
28k
views
Why does trying to break into the NT 3.1 kernel reboot my 486DX4 machine?
I installed Windows NT 3.1 on a Compaq ProSignia 3080 system, because of several reasons: I know that this machine was running Windows NT 3.1 when it was in productive use. And I think this machine ...
- 7,096
146
votes
5
answers
50k
views
It's now safe to turn off your computer
One thing I remember very well from my childhood is the screen you got at the end of a shutdown process on old computers:
I don't know if this was a Windows 95/98/2000/ME only thing but I wonder why ...
- 1,331
144
votes
6
answers
20k
views
Why is the keyboard and cellphone / telephone numbers in a different order?
Cellphone / Telephone have the seven bottom-left and the one top-left.
While the keyboard has the seven top-left and the one bottom-left
How did this come to be? Is there an interesting computing ...
- 5,853
124
votes
2
answers
22k
views
How did Commodore's anti-Microsoft Easter Egg work?
A couple years ago the Toronto PET Users Group published an article (The Great Commodore/Microsoft Easter Egg War, on p. 7) about a newly discovered anti-Microsoft Easter Egg that Commodore hid in the ...
- 1,245
114
votes
5
answers
26k
views
How can tilting a N64 cartridge cause such subtle glitches?
When the N64 cartridge is tilted in Super Mario 64, it reliably produces glitches such as this. Mario's limbs disappear, he rotates 90° and sinks into the floor, and the music gets messed up (usually ...
- 1,243
112
votes
23
answers
38k
views
Was there ever any reason to wait 30 seconds to restart a c.1995 PC?
I owned a PC in the mid-to-late 90s, and while everyone said when you turn it off and back on again, count to 30. But it also had an instant reset button down below. Was there ever really any risk ...
- 1,161
107
votes
10
answers
42k
views
Why do C to Z80 compilers produce poor code?
When reading some other questions about compiling C for the Z80,
How much benefit should be expected on a more advanced compiler for z80/r800 based computers?
Native C compiler for Sinclair ZX ...
- 37.9k
107
votes
7
answers
26k
views
Why was `!` chosen for negation?
It seems that the use of the exclamation mark ! to denote negation started with the C programming language (as far as I can tell from my Google research). Nowhere though is mentioned who and why chose ...
- 1,079
103
votes
18
answers
25k
views
How was early randomness generated?
Many programs make use of randomness, from BASIC guess-the-number games to encryption key generators. This randomness could have been generated in many, many different ways: hardware, software, ...
- 18.3k
103
votes
16
answers
24k
views
Does "Disk Operating System" imply that there was a "non-disk" Operating System?
In the 1980's at primary school we saw MS-DOS and DR DOS competing before Windows 3.1 and subsequent releases took over that space.
At home we had Apple II's which booted up to a BASIC prompt. On ...
- 2,565
101
votes
19
answers
21k
views
How did people use ed?
ed was the standard Unix editor, and is present on all POSIX certified systems (though it's not installed by default in Debian, FWIW).
It's a line editor (meaning, you can't see all the text at a ...
- 1,543
100
votes
6
answers
43k
views
Exactly what color was the text on monochrome terminals with green-on-black and amber-on-black screens?
I am wondering what were the color shades and brightness of the text appearing on classic monochrome terminals?
If I were to recreate approximately the green-text-on-black-screen or amber-text-on-...
- 1,131
99
votes
6
answers
10k
views
Were there 8086 coprocessors other than the 8087?
The 8087 math coprocessor for the 8086 (and descendants) nominally added floating point and transcendental (trigonometric and logarithmic) instructions to the 8086. Contrary to naive expectations, the ...
- 2,635
98
votes
1
answer
29k
views
Why did MS-DOS applications built using Turbo Pascal fail to start with a division by zero error on faster systems?
On faster MS-DOS systems, it wasn't entirely uncommon for applications built using Borland's Turbo Pascal to fail to start, and (before exiting back to the command prompt) to report a division by zero ...
- 5,226
96
votes
11
answers
14k
views
What key factor led to the sudden commercial success of MS Windows with v3.0?
Microsoft Windows was originally introduced in 1985, ostensibly to compete with the Apple Macintosh, and other computers shipping with graphical shells by that time. However, early versions of Windows ...
- 59.8k
95
votes
7
answers
28k
views
Why would a NES game use an undocumented 1-byte or 2-byte NOP in production?
Reading the NESdev wiki page on CPU unofficial opcodes, I see a few games use an undocumented 2-byte NOP instuction in production: Puzznic, F-117A Stealth Fighter, and Infiltrator use $89 #i. Beauty ...
- 9,392
92
votes
3
answers
22k
views
Why does part of the Windows 98 Setup program look older than the rest?
When installing Windows 98, the part of the setup process where you enter things like product details looks... different. The scrollbars, buttons, title bar and such look more like they belong in ...
- 981
91
votes
10
answers
32k
views
How much better was DEC Alpha than contemporaneous x86?
The DEC Alpha, released in 1992, seems like an early implementation of a fully 64-bit microprocessor architecture. Its release led to quite a bit of both marketing hype and genuine vendor support in ...
- 59.8k
91
votes
3
answers
16k
views
How did Windows 3.1 implement multitasking?
Windows in its earliest days was simply a shell that ran on top of MS-DOS, which means that Windows 3.1 itself was actually just a standard MS-DOS application like any other.
Yet, MS-DOS is not a ...
- 2,857
90
votes
20
answers
20k
views
Have programming languages driven hardware development?
Programming language development has been influenced by hardware design. One example from this answer mentions how C pointers were, at least in part, influenced by the design of the PDP-11. Has the ...
- 863
87
votes
9
answers
19k
views
Why did modems have speakers?
Everyone who used early telecommunications services, not to mention the early dial-up Internet services, is familiar with the tones and hissing sounds of a modem establishing a connection. I recall ...
- 59.8k
87
votes
9
answers
14k
views
Why is the processor instruction called "move", not "copy"?
Many processors have an instruction called "move" (sometimes spelled MOV) which copies data from one location (the "source") to another (the "destination") in registers and/or memory. It does not do ...
- 2,077
85
votes
2
answers
32k
views
Is there any code in Firefox (as of 2020) that comes from Netscape Navigator?
Inspired by comments on the previous question Is it true that Netscape Navigator eventually became Mozilla Firefox? (Answer: Yes).
In 1998, Netscape released a large amount of their existing source ...
- 883
84
votes
18
answers
18k
views
Why was BASIC built into so many operating systems?
There are a lot of retro-computers with BASIC as an integral part of the operating system. The IBM 5100 was one of the first computers with a separate memory space for BASIC, followed by the Commodore ...
- 18.3k
83
votes
3
answers
21k
views
Why does the Minus World exist?
In Super Mario Bros. for the NES and Famicom there exists a secret world, accessible by clipping through a wall to the first warp zone and entering the left-most pipe.
This pipe will take you to ...
- 18.3k
81
votes
10
answers
27k
views
How were the first ZX Spectrum games written?
Being a child of the 80s I loved my ZX Spectrum, did my best to learn BASIC but I felt like the games I was playing (Jetpac, Dizzy, Renegade etc) were perhaps not written using BASIC.
I wondered: how ...
- 1,057
80
votes
17
answers
19k
views
Did any 8-bit computer system / OS have concepts for concurrency and multitasking like we know from today?
So, today all major OS support multitasking and concurrency in languages like for instance threading.
The Amiga seems to be the first home computer which has advanced concepts in this area. But had ...
- 1,337
80
votes
14
answers
19k
views
Back in the late 1980s, how was commercial software for 8-bit home computers developed?
When hobbyists wanted to write software for e.g. the Commodore 64, they either used the built-in BASIC interpreter (with all its limitations) or some native tools, like compilers for other languages ...
- 1,502
80
votes
1
answer
56k
views
How exactly does Sonic & Knuckles' 'Lock-On Technology' work?
The cartridge of Sonic & Knuckles is a little special:
It flips open to allow you to connect another Sega Mega Drive (Genesis in US) cartridge to the top of it like so:
I know why the Sega ...
- 970
78
votes
9
answers
14k
views
Why were CLIs typically light text on dark background, whereas GUIs typically use(d) dark text on light background?
My experience is that CLIs were typically shown with light text on a darker background. For example, the IBM PC would use white/light gray (depending on your point of view), amber or green (the latter ...
- 5,226
78
votes
4
answers
26k
views
Why is Windows using CR+LF and Unix just LF when Unix is the older system?
Windows and MS-DOS use the control characters CR+LF (carriage return ASCII 13 followed by line feed ASCII 10) for new lines, while Unix uses just LF.
As far as I know CR+LF made sense for systems ...
- 1,073
76
votes
2
answers
16k
views
Why does the infamous "ENGAGERIDLEYMOTHERFUCKER" Metroid password break NES emulators?
For those who are unfamiliar, the original NES Metroid was one of many NES games to use passwords as a means to save progress.
Later, this password system was leveraged to create unusual effects in ...
- 3,981
75
votes
8
answers
21k
views
Why did IBM make the PC BIOS source code public?
IBM released the IBM 5150 Technical Reference manual in August, 1981, and included in it the fully commented source code listing for the BIOS. I find this odd for two reasons:
IBM must have realized ...
- 59.8k
75
votes
7
answers
14k
views
Why wasn't ASCII designed with a contiguous alphanumeric character order?
Anyone who has dealt with strings at a low level (e.g., writing a parser in C), knows that doing so tends to involve frequent checks of—either manually, or through isalpha(), isalnum(), etc—whether a ...
- 753
75
votes
7
answers
9k
views
What technological factors drove the rise of "high-speed" modems in the early 1990s?
The first inexpensive modem I ever purchased was a 300 baud direct-connect unit for the C64 User Port in late 1983. I recall that a couple of years later (1986), 1200 baud modems were affordable and I ...
- 59.8k
75
votes
4
answers
16k
views
What made Windows Me so crash-prone?
Many people remember this operating system as not exactly a walk in the park, namely that it could crash as early as during the installation phase or at unexpected times when the user wasn't doing ...
- 6,338
73
votes
5
answers
17k
views
Why did C use the arrow (->) operator instead of reusing the dot (.) operator?
In the C programming language, the syntax to access the member of a structure is
structure.member
However, a member of a structure referenced by a pointer is written as
pointer->member
...
- 15.7k
73
votes
7
answers
37k
views
Why was the Kickstart 1.x "Insert floppy" graphic so bad?
Anyone who used an pre-Kickstart 2.0 Amiga will be very familiar with the "Insert Workbench floppy" image:
I realise that this is subjective, but the image has always stuck me as ... well, a bit ugly....
- 1,841
71
votes
8
answers
23k
views
Which Linux or BSD distributions do still support i386, i486 or i586 CPUs?
Unfortunately Debian kicked out Pentium 1 (i586) CPU support from its 32-bit PC port (named i386 for historic circumstances) for its next stable release Debian 9 Stretch. (Then again they complain ...
- 955
70
votes
3
answers
13k
views
Why did DOS use dollar-terminated strings?
According to a few tutorials I am seeing, DOS used dollar-terminated strings to write to the terminal. This seems to also be documented here on INT 21H.
AH = 09h - WRITE STRING TO STANDARD OUTPUT
...
- 3,328
70
votes
3
answers
6k
views
Why was the return key symbol ↵ drawn differently from the motion of a CR-LF?
In the operating system (DOS) of IBM PCs, newlines were represented by a carriage return (CR) character, followed by a line feed (LF) character. The motion of a printer or teletype receiving such a ...
- 15.7k
70
votes
3
answers
9k
views
Why did Unix use slash as the directory separator?
The Unix designers came from the GE/MIT Multics project, and Multics inspired some Unix features. In particular, Multics has a hierarchical filesystem, and so does Unix.
On Multics, pathnames were of ...
- 1,695
68
votes
12
answers
18k
views
Did Apple not originally allow anyone to develop software for the Macintosh?
This probably nearly belongs on Skeptics.SE but here goes.
Within the last few years I've become an Apple convert for the most part, which occasionally brings me into (usually) good natured conflict ...
- 863
68
votes
3
answers
15k
views
What character is the MS-DOS cursor?
The cursor used on my 486 (and Pentium 3) in MS-DOS 6/7 has a thick underlined character. I cannot find that in code page 437. The underscore character is the closest to it, but is thinner.
Where ...
- 2,893
68
votes
7
answers
16k
views
Where did the popularity of the `i` variable come from?
I have heard that the reason the i variable is used so much is because there was an old computer where each variable could only be a single letter and that reserved the variables a through h as ...
- 2,517
68
votes
6
answers
16k
views
Why did base64 win against uuencode?
From the the two methods of encoding 8-bit data as human-readable ASCII, for a time, uuencode format was more popular. USENET 'binaries' groups were filled with uuencoded posts with whatever goodies ...
- 6,785
66
votes
14
answers
24k
views
Why did some early CPUs use external math chips?
While enjoying the response to "Why did CPU designers in the 70s prioritize reducing pin count?" In 1979 IEEE was hard at work at coming up with a standard for handling floating point numbers, and ...
- 4,469
66
votes
5
answers
10k
views
Back in 1984 I wrote some games for Spectrum - Will they still be playable?
Back in 1984, I was commissioned to write some games for ZX-Spectrum. They were sold together. To my amazement I found that someone is selling a copy online.
I thought of buying it but it is in the ...
- 1,151