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1500 questions
22
votes
5 answers
Was it feasible to create Win16 software using pre-existing DOS development tools?
It seems that right from the outset, the plan for Windows development was that it would be done with a separate set of compilers specifically equipped for that purpose.
The Windows SDK comes with 7 diskettes, with all the tools you need including…
rakslice
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22
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2 answers
What happened to bubble memory - is it still being sold?
At one time bubble memory was advertised as being able to store huge amounts of data in the size of a sugar cube. I don't remember what the memory density was compared to today's SD cards. What happened to bubble memory - is it still being sold?
Barnstormer
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22
votes
3 answers
How did "full memory" Spectrum tape copiers work?
There are some tape copiers, such as LERM that claim to be able to copy tapes which contain software that takes the full 48kbyte of RAM.
However, this seems impossible on a Spectrum, when the whole 48kb is read from a single file on disk.
How do…
Sklivvz
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22
votes
2 answers
How do I use shadowed memory to render Super Hi-Res quickly?
The Apple IIgs video memory is controlled by the 1MHz Mega II chip, so directly accessing the Super Hi-Res page in bank $E1 is slower than accessing other memory. How can I render in "fast" memory, and then just copy the final result to "slow"…
fadden
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22
votes
3 answers
Does an ISA card have a fixed memory address?
A PCI card does not have a fixed memory address, the PCI card specifies how much memory it wants, and the OS will assign whatever address it wants for this memory, and will set this address in the PCI card's BAR field (of course a PCI card can have…
user8240761
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22
votes
5 answers
PDP-11 instruction set inconsistencies
The wiki page PDP-11 architecture has a cryptic paragraph with no references or examples:
Inconsistent instructions
Over the life of the PDP-11, subtle differences arose in the implementation of instructions and combinations of addressing modes,…
Leo B.
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22
votes
4 answers
How did the Amiga 500 left-side expansion port work?
On the Amiga 500 there is an expansion port
How did the expansion port work?
Thraka
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22
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2 answers
How can I programmatically tell which version of Apple II my code is on?
There are minor and major differences between the many Apple II models.
I would like to detect whether my 8-bit assembly language program is running on a II, II+, IIe (enhanced or not), or ///, and which ROM version if on a //c or IIgs.
Also, are…
Nick Westgate
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22
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3 answers
How was 8-channel audio achieved on Amiga?
Oktalyzer was a Tracker style program for Amiga, that allowed composing and playing music with 8 channels instead of the "hardware-natural" 4.
So far I learned it achieved that by splitting the 4 8-bit channels into 8 4-bit ones. But I still don't…
SF.
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22
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2 answers
What was the first C compiler for the IBM PC?
When did a C compiler first become available for the IBM PC? I have fond memories of Turbo C, but that didn't become available until the mid to late eighties; it definitely wasn't the first one. Languages available at launch seem to have been Basic,…
rwallace
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22
votes
2 answers
How do old computer emulators work?
I'm wondering how old computer emulators work.
I can think of two possible approaches:
"hardware" approach - like a set of components that exactly act as low-level hardware elements. I mean a bus with its busy signals, CPU and fetch–decode–execute…
Adam
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22
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3 answers
How could the Intel 4004 address 640 bytes if it was only 4-bit?
I am reading Computer Organization and Architecture, 10th ed. by William Stallings and I found this on page 26.
where it says the addressable memory of 4004 is 640 bytes.
But it appears that the Intel 4004 only had 4 pins for "MEMORY CONTROL…
Noob_Guy
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22
votes
2 answers
How was the order of Unicode block-quadrant characters chosen?
Unicode codepoints 0x2596–0x259f can help you draw primitive graphics by offering all the combinations of on or off for the four quadrants of a glyph. They're available in this order:
▖ ▗ ▘ ▙ ▚ ▛ ▜ ▝ ▞ ▟
00 00 10 10 10 11 11 01 01 01
10 01…
Daniel Wagner
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22
votes
1 answer
Why did Windows 3.0 fail in Japan?
According to The launch of Windows 3.1 in Japan was such a big event that they even called it “Windows Day” (Bullfrag):
When Microsoft released Windows 3.0 in the United States in 1990, they were selling about a million copies a month. Meanwhile,…
rwallace
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22
votes
1 answer
Looking for help understanding a 'Reciproot' routine on the Manchester Mark I (1951)
I'm hoping to understand a routine written for the Manchester Mark I [NOTE: a comment from Raffzahn suggests this may be the Ferranti (wikipedia link) and not the Manchester Mark I] which computes the reciprocal square root (1 / √x). The Mark I had…
Adam Hyland
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