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1500 questions
17
votes
4 answers
Booting an Amiga 1000 directly to the hard drive without Kickstart floppy
The Amiga computers such as the Amiga 1000 required a Kickstart floppy to be able to boot directly into a hard drive. I have a Amiga 1000 as well but missing the Kickstart floppy. I would like to access the hard drive for my personal use with the…
Anthony Pham
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17
votes
5 answers
What was the first mass-market, 16-bit microcomputer system?
To qualify what I mean by "16-bit microcomputer system", I am talking about a system that has not only a 16-bit (or 32-bit) microprocessor CPU, but also a 16-bit wide external data bus connected to the rest of the system. So, 16-bit access to its…
Brian H
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17
votes
2 answers
What is this diskette drive?
I am preparing a BBC Model B micro computer for sale which has been in storage and needs cleaning. There is a 3½" diskette drive with it, which was unfortunately stored with the slot uppermost and there is a lot of dust inside the drive itself.
When…
Weather Vane
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17
votes
2 answers
Why would installing a 486DX2 make the system freeze for minutes on boot?
In the mid-1990s, a friend of mine had one of those Compaq Presario desktop PCs that had an integrated CRT SVGA display built in the same cabinet as the CPU, in a similar fashion as the early iMacs. The machine has long since been disposed, and I…
mkay
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17
votes
3 answers
Apple II: DOS 3.3 Virus?
Does anyone know the source of this Apple II DOS 3.3 virus that infected my disks back in the 1990's? I got it from a public domain disk collection that was given to me by a friend, called the Freeloader Library, which was sold commercially in the…
Dale Mahalko
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17
votes
1 answer
TMP/TEMP Environment variables in Microsoft operating systems
The environment variables %TMP% and %TEMP% are the same. Reading the interesting Raymond Chen blog https://devblogs.microsoft.com/oldnewthing/20150417-00/?p=44213, it seems that %TEMP% was introduced in MS-DOS 2.0.
MS-DOS 2.0 introduced the ability…
Single Malt
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17
votes
3 answers
Status of brute forcing all possible memory states of a video game
For an old video game that has a small enough memory footprint, it should be possible on exponentially larger modern systems to create a graph of all possible states of memory and the inputs that transition between them. With this information, one…
TomKern
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17
votes
2 answers
How did the Sun-1 handle page faults despite having the original 68000 processor?
The Sun-1 was Sun Microsystems' first Unix workstation. As described in its Wikipedia article, it had a Motorola MC68000 processor and a custom memory management unit:
The Sun-1 MMU was necessary because the Motorola 68451 MMU did not always work…
DrSheldon
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17
votes
1 answer
Why was the 6502 version of Microsoft BASIC coded like the 8080 and 6800 versions even though this was rather inefficient?
It's quite clear that the 6502 version of Microsoft BASIC at all levels uses substantially the same structure and technique as the earlier 8080 and 6800 versions. As has been pointed out in various places on this site and elsewhere, this came at a…
cjs
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17
votes
2 answers
Can I really change standard operator priorities in ALGOL 68?
In Algol 68, I can declare the priority (precedence) of an operator-symbol:
prio @ = 5;
(Higher number means higher precedence).
I can apparently redefine the priorities of built-in operators:
begin
prio + = 7, x = 6;
print(2+3x4)
…
dave
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17
votes
1 answer
Was any commercial end-user software written in PROMAL?
PROMAL is a procedural programming language from the 1980s. Its designer, Systems Management Associates, released compilers for the Commodore 64, Apple II, and IBM PC. The language and development tools received excellent reviews in the home…
Psychonaut
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17
votes
2 answers
What should I do when some of the keys of my Amiga 600 have stopped working?
I opened up an Amiga 600 to install a hard drive, and after reconnecting the keyboard ribbon and powering the computer up, at least one column of keys no longer works. What did I do wrong and what can I do to fix it?
rcntxtlztn
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17
votes
2 answers
Why did the 8080's PUSH PSW write one reserved bit as 1 and the other two as 0?
The x86 "flags" register, which holds condition codes and other processor status bits, has several reserved bits with fixed values, but these fixed values are not all the same. In particular, bit #1 (the twos place, considering the register as…
zwol
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17
votes
4 answers
Why was Wireplay "faster and more reliable" than dial-up Internet, since they both used the same hardware?
In 1997, there was this service called Wireplay in the UK.
Instead of using the Internet, you used it by directly phoning their servers with your modem from your PC, and the point of this was that it was "much faster and more reliable" than an…
Rosero
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17
votes
6 answers
How does a floppy drive identify the first and last sectors and tracks?
I've recently found a more modern application "Floppy Disk Master-7"(Picture 2) (FDM) that visualized the bad sectors, tracks and clusters(Picture 1) on a floppy disk in a similar (but fancier) way to the older "Norton Disk Doctor"(Picture 3)…
Bob Ortiz
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