All Questions

4
votes
1answer
213 views

What is the difference between CTSS and ITS?

I learned from the history of Multics in early days if Computers, Time Sharing System had used at MIT and later on Compatible Time Sharing System (CTSS) had developed in 1961 and used at MIT. In July ...
3
votes
1answer
98 views

Is it possible to write IIgs floppies from a Powermac 7100?

I haven't gotten around to making/sourcing a cable for ADTPro, but I was thinking perhaps I can just write a few disks with a 7100 I have sitting around since those drives can read/write GS and PC ...
3
votes
3answers
150 views

Is the IBM 5153 color display compatible with the Tandy 1000 16 color modes?

Is it possible to view games made for Tandy Graphics (TGA, etc) on an IBM 5153 color display connected to an original Tandy 1000 (or 1000/A) in 16 colors?
35
votes
5answers
5k views

Did any compiler fully use Intel x87 80-bit floating point?

There is a paradox about floating point that I'm trying to understand. Floating point is an eternal struggle with the problem that real numbers are both essential and incomputable. It's the best ...
14
votes
3answers
950 views

What order were files/directories output in dir?

In the version of command.com included with MS-DOS, DIR seems to print files in a random order, but if one runs multiple DIR commands, they all print the files in the same order. This order does not ...
5
votes
4answers
379 views

What was the first time a programmer was able to use the well know block structure for conditional code?

The easily readable structure of having an if keyword which controls execution of a following block of code is so prevalent in programming that it seems to just be part of it. However, programming ...
26
votes
6answers
5k views

Why weren't discrete x86 CPUs ever used in game hardware?

Please don't point out APUs with x86_64 cores used in current generation game consoles, these are not part of the question I cannot recall a single arcade system or game console that ever used x86 ...
3
votes
3answers
239 views

What was the first language to offer “full” structured programming support?

In the same vein as this question about conditionals, I am interested in the first time a language provided functionality we assume as a given for modern programming languages. The question is when a ...
10
votes
4answers
2k views

What was the first language to use conditional keywords?

The if keyword is so prevalent in programming that it seems to just be part of it. However, with an integer value and a goto statement, one cansimulate the functionality of an if. Which means it's ...
6
votes
1answer
157 views

How can I input a string in ZX Spectrum BASIC using INPUT and not show the quotation marks?

How can I input a string in ZX Spectrum BASIC and not show the quotation marks on input? I've written a program for my 3-year old daughter to type in some letters, but she keeps deleting the ...
14
votes
2answers
3k views

Did MS DOS itself ever use blinking text?

I know that it was possible to create blinking text, but did the operating system itself (I mean, in output from functions of command.com and similar executables) ever make use of blink formatting? ...
0
votes
2answers
203 views

What was the first language compiler to support subtype polymorphism? [closed]

I'm trying to understand the history of Dependency Injection in compiled languages, as an intentional feature of the language. The Wikipedia article on the subject is decidedly Java focused, but I ...
25
votes
3answers
4k views

Why wasn't DOSKEY integrated with COMMAND.COM?

Why did Microsoft make DOSKEY a separate command, instead of integrating it with COMMAND.COM? I don't think DOSKEY uses a lot of RAM or was useless in the '80s... Maybe there was another reason not ...
8
votes
5answers
335 views

Build automation tools before make?

I realized that make was "only" invented in 1976 and seems to be one of the first build automation tools (at least it's probably the oldest still in use). Make with its shell focus seems like a total ...
16
votes
4answers
3k views

What was the first console to have temporary backward compatibility?

The first five generations of game consoles typically had no backward compatibility. New console, new hardware design, new games. (An exception was the Atari 7800, which as far as I know was the first ...
6
votes
1answer
262 views

When did MS Windows get Dual Monitor support?

I remember one of the features I admired on the Macintosh in the late 80s was support for multiple displays. First time I saw this was on an SE/30, using the internal display along with a big external ...
5
votes
2answers
289 views

Is there a program I can run on the C64 to speed up booting of a game?

Though I had several friends back in the day with a Commodore 64, I only recently acquired one after a friend gave me his old one before he moved house. As such, I'm diving in to learning about the ...
6
votes
2answers
315 views

Name this Macintosh music application

There's an application that's been on my mind on and off for months now, I want to find clarity. Once upon a time, when MacOS was in black and white, there was a neat music composer/player ...
4
votes
1answer
123 views

What is the maximum voltage of high voltage differential SCSI?

Is the maximum voltage of high voltage differential SCSI documented somewhere? All I can find in various source like Wikipedia is that it is "greater than 5 volts" ... but how high can it actually be? ...
3
votes
1answer
167 views

IBM 650 - how many logic gates?

How many logic gates did the IBM 650 have? I'm used to measuring the complexity of a CPU by transistor count, but the 650 was a vacuum tube machine; the number of tubes would also be an interesting ...
18
votes
7answers
16k views

What does the “x” in “x86” represent?

I have read the following in the x86 Wikipedia page: The term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 ...
12
votes
2answers
2k views

Did Xerox really develop the first LAN? [closed]

Did the computer scientist at Xerox really develop the first LAN, but had no backing from the company to further develop these technologies, later showing this to both Steve Jobs and Bill Gates? Just ...
3
votes
1answer
323 views

Did Xerox engineers really develop the first graphical user interface? [closed]

Did the computer scientist at Xerox really develop the first graphical user interface, later showing this to both Steve Jobs and Bill Gates? Just for reference, it is in reference to this story.
14
votes
1answer
580 views

How does a biquinary adder work?

I whipped together a quick answer to this question and then realised, that I have no idea how these tubes manipulate the numbers. A binary adder is easy to understand to the modern mind; for each bit ...
44
votes
2answers
5k views

Why did the IBM 650 use bi-quinary?

The IBM 650, announced in 1953, was the world's first mass-produced computer. It represented numbers in decimal, which is understandable, both because it needed to work with exact money amounts, and ...
11
votes
1answer
307 views

How were Zuse Z22 Instructions Encoded?

The title says it all: How to En-/Decode Z22/Z23 Instructions? (History and Linkage: The question was raised by Wilson in a comment on my answer to his question "Why are PDP-7-style microprogrammed ...
12
votes
2answers
2k views

Why are PDP-7-style microprogrammed instructions out of vogue?

DEC, and at least some of their computers, especially those in the 18-bit family and 12-bit family, had these opr instructions, which contained many bitfields which encoded something like "...
12
votes
2answers
313 views

Protected/virtual memory support in classic AmigaOS

It is a well-known fact that AmigaOS is a single address space, totally unprotected memory operating system. The original implementation ran on a Motorola 68000, that did not support virtual memory if ...
22
votes
2answers
5k views

What was the last x86 CPU that did not have the x87 floating-point unit built in?

This Wikipedia page says the following: Most x86 processors since the Intel 80486 have had these x87 instructions implemented in the main CPU So the above quote implies that some CPUs that were ...
5
votes
1answer
280 views

What can an 8086 CPU do if an x87 floating-point coprocessor is attached to it? [duplicate]

As far as I know, old x86 CPUs (for example: the 8086 CPU) couldn't do floating point arithmetic, and in order to be able to do floating-point arithmetic, an x87 floating-point coprocessor should be ...
14
votes
4answers
4k views

Did any laptop computers have a built-in 5 1/4 inch floppy drive?

In the early era of "portable" or luggable computers, such as the mains powered Osborne 1 and the Compaq Portable, 5 1/4 inch floppy drives were the standard storage medium. When battery-powered ...
2
votes
2answers
432 views

What is a .95END file?

While cleaning out some old computers owned by my grandfather I came across some files marked with the file format .95END that had creation dates in early 1995 (though they could be from much earlier, ...
10
votes
2answers
364 views

What role did the BBC have in the development and marketing of Acorn Archimedes computers?

The BBC's Computer Literacy Project was launched in 1982, and saw the public service broadcaster seek to raise awareness and educate the general public about the growing field of computing. They ...
12
votes
1answer
2k views

Why did Acorn's A3000 have red function keys?

Acorn's line of ARM-based Archimedes computers was common in UK schools in the 1990s, and many classrooms had an A3000, A4000, or A5000 computer. The function keys of the A3000 were a distinctive red ...
9
votes
2answers
750 views

Why could you hear an Amstrad CPC working?

I had my first programming experience in the late 80s / early 90s on a Schneider (Amstrad) CPC 464 in Basic. I remember that when a program was running, depending on the current workload of the ...
5
votes
2answers
316 views

Was Apple's Developer Release DR1 of Copland ever distributed?

From 1994 to 1996 Apple developed a complete new Mac OS, codenamed Copland, intended to be published as System 8. A first public demo was made at the May 1996 WWDC. Shortly before it was canceled, a ...
7
votes
1answer
241 views

How were arcade games developed?

For some systems, such as the Super NES (SNES), there existed a development kit, which consisted of specialized hardware. I believe this kit allowed the developer to present recently assembled machine ...
2
votes
2answers
166 views

Sinclair ZX Spectrum with DivMMC load issue

I use a Sinclair ZX Spectrum Issue 2 with a DivMMC EnJOY! Pro One and the boot process shows no error and I'm even able to enter the file browser but if I choose any game/demo/program I get always ...
4
votes
2answers
213 views

DOS/4DOS Prompt with animated characters?

I have a vivid memory of a guy I knew back in the day who had a custom prompt with a small character animation. The way I remember it there was a sequence like |,/,--,\,| in the prompt. This wasn't ...
10
votes
3answers
1k views

DOS, create pipe for stdin/stdout of command.com(or 4dos.com) in C or Batch?

I'm working on a retro project and was trying to create a pipe of stdin/out/err in DOS, but I can't find any functions to to this? For instance the pipe() command from unistd.h isn't present in ...
0
votes
2answers
49 views

DOS, create pipe for stdin/stdout of command.com(or 4dos.com) in C or Batch? [duplicate]

I'm working on a retro project and was trying to create a pipe of stdin/out/err in DOS, but I can't find any functions to to this? For instance the pipe() command from unistd.h isn't present in ...
2
votes
1answer
128 views

Why was the DEC Q-Bus called the Q-bus?

The bus used for DEC's LSI-11 microcomputer implementation of the PDP-11 was originally and prosaically referred to as the LSI-11 bus, but thereafter it was universally referred to as the Q-bus. Does ...
1
vote
2answers
245 views

IBM PC memory map - why RAM at the bottom?

The 8088 provided an address space of one megabyte. The IBM PC allocated that address space as 640K RAM (not that the 5150 could physically take that much, but the address space was allocated) ...
2
votes
1answer
113 views

Windows 98 hangs after entering password on fresh install

I am doing a fresh reinstall of Windows 98 SE on a Dell Optiplex GX1 550Mbr+. I previously had this very same version of Windows on this machine. The install works perfectly, but when I get to the ...
9
votes
5answers
260 views

Alternatives for TurboVision on DOS

TurboVision was a library by Borland for developing TUI's (Text User Interfaces). It was included with their C++ and Pascal compilers. Were there any other TUI libraries that supported multiple ...
2
votes
2answers
94 views

What are the HSync and VSync frequencies of these common VGA tweak modes?

Most VGA cards and monitors support additional undocumented resolutions, accessed by changing the VGA registers. Most are just variations on the regular modes (320x100 is the same as 320x200, but with ...
3
votes
2answers
315 views

How did 2-chip CPUs work?

The 1970s saw a big transition from CPUs built from thousands of discrete components, to CPUs implemented on a single chip, with the occasional use of bit-slice components along the way. There were, ...
0
votes
1answer
113 views

Why did CGA RGBI output leave DAC to the monitor?

CGA on the original IBM PC produced sixteen colors, one bit each for red, green, blue and overall intensity modifier. The preferred output device was the later-arriving 5153 color monitor, which ...
33
votes
2answers
4k views

Can an x86 CPU running in real mode be considered to be basically an 8086 CPU?

When an x86 CPU is running in real mode, can it be considered to be basically an 8086 CPU (or maybe 8088)? Or are there differences between the two?
2
votes
1answer
128 views

IBM 5153 vs color TV in actual picture tube

The IBM 5153 Personal Computer Color Display was a monitor designed to accompany the original IBM PC (albeit released a couple of years later) and provide a color display at sharp enough resolution ...

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