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3
votes
1answer
651 views

Why does the Vic-20 have two VIA chips?

The Vic-20 uses the 6522 VIA for peripheral I/O. However, it has two of them. I find this surprising, particularly considering minimizing cost was an important design goal. Is there a reason why it ...
5
votes
3answers
440 views

What is the difference between the 6522 VIA and a UART?

The 6522 VIA is an I/O chip used in the Vic-20. I was under the impression that UART (Universal Asynchronous Receiver/Transmitter) is the general term for such chips, so was surprised to see this: ...
42
votes
12answers
7k views

Was it actually possible to do the cartoon “coin on a string trick” for old arcade and slot machines?

In cartoons, you often see characters like Scrooge McDuck with a coin where they have drilled a hole in the middle and attached a string, enabling them to insert the coin multiple times and keep ...
11
votes
3answers
556 views

What was the earliest use of |> pipe in programming?

I am trying to find which language used the |> operator first. It's being discussed for use in R, and it's been in OCaml for some years. Did it originate in OCaml? If not, what are its earliest ...
7
votes
1answer
3k views

How do I find out the REAL title of a given video game?

The Wave Race game for Nintendo 64 is called "Wave Race 64 - Kawasaki Jet Ski" in a ROM set. On Wikipedia, which I've previously considered authoritative for titles of commercial products, ...
10
votes
4answers
511 views

Commodore BASIC: why was the PET's GOTO so slow?

Received wisdom has it that Commodore didn't want to pay Microsoft extra for updated BASIC interpreters, and thus very little changed in Commodore BASIC v2 from the PETs to the C64. But consider the ...
20
votes
11answers
5k views

Did any European computers use 10-line fonts?

Most 8-bit computers implemented hardware text mode, and most of those used 8x8 fonts. This was logical for American computers; the title safe area on NTSC is about 200 scan lines; font height 8 gets ...
11
votes
2answers
467 views

How did 512 Bytes come to be the most common sector size?

It was long assumed by FS drivers that all diskette and harddisk units operate in blocks of size 512 Bytes. How did this happen to be the case, historically? Why not the "neater" 1 KiB, say?
18
votes
2answers
3k views

How did AMD's 386 and 486 perform like Intel's newer generation?

AMD really started to come into its own as a competitor to Intel around the time of the Intel 80486 introduction. AMD countered Intel by shipping the popular (at least with PC enthusiasts) Am386-40, ...
10
votes
2answers
2k views

Why does my CRT whine?

My Amstrad CTM644 CRT 'monitor' (really a TV grade tube with RGB inputs), makes a high pitched whine when powered on, audible to my children and cats, though no longer to my own ears. My research ...
10
votes
4answers
1k views

Physical resolution and control of old VGA (color) CRT monitors

I've just realized I have a gap in my understanding of the VGA CRT monitors of the 80386 era (1980s-1990s). What was the phosphor resolution? It turns out I did not have proper understanding of the ...
30
votes
3answers
4k views

Why is the ‘auto’ storage class specifier included in C?

The auto keyword in C seems quite redundant: wherever it makes sense to define a variable with automatic storage duration, it is already the default, so there is no reason to use the keyword. The ...
2
votes
1answer
423 views

Identify computer seen in Wikipedia

I remember browsing in WikiPedia a year or two ago and found an interesting old computer running some UNIX or similar os, where the screenshot of the terminal was amusing because it was a computer or ...
11
votes
1answer
2k views

Why was the 1541 so slow?

The Commodore 1541 floppy disk drive, sold for use with the 64, was notoriously slow for historical and technical reasons: Marketing insisted on compatibility with the 1540, the floppy drive sold ...
1
vote
0answers
64 views

Run ca65 assembler with intermediate step of resolving macros

I would like to convert an assembler program in ca65 with macros into assembler code with resolved macros in order to carry out manual or automatic optimizations with the resulting code. Then, the ...
9
votes
4answers
1k views

Modulus arithmetic on the 6502

I have a very simple problem with is turning out to be surprisingly complex to solve. I wish to add two bytes using modulus arithmetic, where the modulus is known at compile time. e.g. given modulus 5,...
7
votes
4answers
2k views

Could any computers use 16k or 64k RAM chips?

An interesting feature of the Apple II was that it had three rows of sockets for RAM chips, each of which could take either 4k or 16k chips. That meant the minimum configuration was 4K (cheap) but it ...
3
votes
1answer
219 views

What stealthy NES game had that profile-view darkness/searchlight area?

When I was a kid, probably around 1990-1992, I was at my cousins' house and they played NES. I vividly remember a side-scrolling stage which either was dark the whole time, or alternated between being ...
1
vote
2answers
205 views

AST Laptop With No OS

I work in network design/IT for a church, and a someone came in with a AST Advantage Explorer 486SX/33. It looks like it has no OS. After failing to boot, it requests to go to the BIOS to look for an ...
7
votes
1answer
635 views

What non-Spectrum computers did Sinclair sell 4 million of?

Reading Alan Sugar : The Amstrad Story, I just came across one of those little oddities that initially manifest as 'huh, wait a minute' and sometimes just mean someone has made a typo, and sometimes ...
-1
votes
1answer
466 views

How common was it for people who owned a PlayStation back in the day to never actually buy games, but only play demo discs? [closed]

The PlayStation, released in late 1995 in the West, was a magical console in a magical era. One of the magical things that made it so magical was the fact that it used cheap and thin CD-ROMs instead ...
4
votes
1answer
191 views

Has a retargetable disassembler been used successfully for a word-oriented mainframe architecture?

Among many modern disassembly/reverse engineering tools, has any been used to disassemble legacy code for a word-oriented mainframe, preferably with a non-power-of-2 word length, like CDC 6600 (60 bit)...
3
votes
2answers
212 views

Did any 5.25" floppy drives not based on the Apple Disk II offer quarter-track control

Unlike many drives, the Apple Disk II has inputs that control the individual head stepper coils. These are commonly described as advancing by half-tracks, since advancing a full track requires ...
2
votes
0answers
103 views

Apple II DMA daisy chain also used to arbitrate /INH?

On the Apple II series of computers, peripheral cards contend for bus mastership through a priority daisy-chain system. A peripheral card is only allowed to perform DMA if its DMA_IN line is at logic ...
0
votes
0answers
152 views

Arcade game with a sit-down cabinet and vibrating seat

I don't know the name of an arcade game; can someone please help? When you go all the way to the ground, your ship turns into a car and your seat vibrates. In the last stage, your ship turns into ...
26
votes
8answers
4k views

Why did DEC develop Alpha instead of continuing with MIPS?

I have been rereading a fascinating discussion about why DEC replaced VAX with Alpha based on talks with people who were there at the time; in a nutshell, in the opinion of the VAX engineers, it was ...
13
votes
8answers
4k views

GOTO (etc) to a non-existent line?

Writing a BASIC interpreter has revealed a number of interesting bits of information that tend not to be mentioned in the documentation. For instance: 10 PRINT"ONE";:IF 1=2 THEN PRINT"...
4
votes
4answers
1k views

IBM vs DEC and business partners

A Quora question Why did Digital Equipment Corporation (DEC) fail? has gathered some really interesting answers, including from former DEC people. There is one such answer I do not quite understand: ...
40
votes
17answers
7k views

Is there any text to speech program that will run on an 8- or 16-bit CPU?

I'm wondering if any of the ancient 1980's style text to speech algorithms were saved from oblivion and are still available. It might be nice to hear that vintage sound like what appeared in War Games....
25
votes
5answers
10k views

Twist in floppy disk cable - hack or intended design?

There are many documents (e.g. this) describing the twist on two-drive floppy disk cable on IBM PC compatibles. While this is not the most proud example of clean hardware design, how much of this was ...
2
votes
1answer
238 views

Bill-of-material cost of early hard drives

Based on this topic (and continuing this topic), my question once again surfaced: And what was the layout of the prime cost of early 8 and 5.25 inch hard drives? From Seagate and competing ...
2
votes
1answer
200 views

Identify Terminals Used in this Music Video

I was watching music videos on YouTube and noticed these machines in the video for the song Who's Behind the Door by the band Zebra. The song was released on their album in 1983, but I don't know ...
4
votes
2answers
164 views

Replacing an 8" disk drive with a newer/smaller drive on an old 8-bit computer?

I used to have an out-phased Danish 8-bit computer as a hobby machine back in the 90's. It had two external 8" floppy drives, and I have kept the old floppies. Now I'd like to salvage my old ...
6
votes
3answers
515 views

How do I get the size of a file on disk on the Commodore 64?

As the title, really. I'm reading a SEQ file into memory, and need to know how big it is ahead of time. I know that I can get the size in blocks by parsing the directory, although it's ugly, but the ...
20
votes
4answers
11k views

Why was “C:” chosen for the first hard drive partition?

I was reading this answer, as the question came to my mind: why does C: indicate the first hard drive partition? The usage dates back to CP/M (as noted in a comment), was embraced by MS-DOS, and ...
13
votes
2answers
1k views

How would I reliably detect the amount of RAM, including Fast RAM?

If I was to write an Amiga game, what would be the best/most reliable way to detect how much RAM is actually available? Looking at Action's Guide to AGA-Fixing!, he mentions Faulty Memory Detection: ...
8
votes
3answers
357 views

What source-code management tools were available for Classic Mac OS development?

I've been reacquainting myself with classic Mac OS programming (e.g. the Toolbox, MacsBug, THINK Pascal/C, etc.) and became curious how software engineering best practices were ...practiced... using ...
27
votes
17answers
6k views

How much did the first hard drives for PCs cost?

I would like to know how much early PC hard drives cost but have only been aable to find adjacent or unsourced data. According to the Centre for Computing History: The "IBM 5161 Expansion ...
3
votes
1answer
297 views

What are these graphical display commands?

I have a Pascal program with a fair amount of inline assembly code in it which demonstrates the capabilities of «Электроника МС 7401» — символьно-графический видеотерминал (Elektronika MS 7401 - ...
8
votes
1answer
616 views

SAG Computer: What System is it?

I recently saw an TV old advert (1983) from an Italian company, called SAGA, that sells a so-called SAG computer. It looks like a microcomputer for SMB, with bundled software. Does anyone know what ...
1
vote
0answers
106 views

How to fix problem with MSX Composite Video?

I have a toshiba HX-10 64KB MSX1 computer (PAL video output). I recently used a new cassette cable which caused a problem with the video;I am using the AV composite audio and video; because the video ...
29
votes
2answers
6k views

Is this a real system? Which one?

I was playing Remedy Entertainment's video game Control the other day. Inside the game world, I've come across several computers. (They all look extremely similar.) To me, it looks like some kind of ...
11
votes
4answers
2k views

Is it possible to just construct a simple cable serial↔︎serial and send data from PC to C64?

I recently saw a video made by the famous "The 8 Bit Guy" about PE6502 computer. At 19:41, he successfully sent a text file from his Windows 95 laptop to the PE6502 using only a standard ...
8
votes
1answer
959 views

Why does the Applesoft BASIC have shapes?

Why did Apple include shapes in Applesoft BASIC? There are no sprites on the Apple II, but shapes provide a simple vector drawing tool. As graphics go the shapes are kind of an odd duck, they provide ...
4
votes
1answer
174 views

When was the Game Boy Pocket released in Europe?

You'd think this would be the simplest thing in the world to find out, but Wikipedia and all other sources just mention the USA and Japan release dates -- not the European one. I have no idea why ...
2
votes
1answer
295 views

Help installing Windows NT 4

I need to install Windows NT 4 on a pentium computer with Windows 98 installed on a Fat32 partition 160 GB drive. I made a 2GB Fat16 primary partition before this c partition with partition magic, ...
2
votes
1answer
103 views

Macintosh IIci not booting

I have an old Macintosh IIci that worked until a few weeks ago but now doesn't turn on anymore. When I press the power button on the keyboard all the lights on the keyboard and the one on the main ...
8
votes
1answer
274 views

Is there a possibility for a user-defined IRQ hardware vector on a Commodore 128 in C128 mode?

When an IRQ occurs, the 6502 microprocessor and its derivatives in the C64 and C128 push the status register to the stack and then load the contents of a two-byte vector at memory address $FFFE/$FFFF ...
6
votes
1answer
98 views

How can I restore the VDC RAM to usable text mode after clearing memory for hi-res graphics?

So, I've got a C-128 with only 16K of VDC video RAM. I've finished my lovely high-resolution graphics routine on the RGBI display and want to exit to BASIC with a functional 80-column text screen, ...
16
votes
2answers
2k views

Why did the 8087 need a special socket?

The IBM PC included a coprocessor socket for the 8087 floating-point unit. Logical enough; some customers wanted to use the 8087 to make numeric calculations run faster. But why was the 8087 designed ...

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