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2 votes
2 answers
448 views

Breakout style arcade game from 90s

I'm looking for a breakout style game where the paddle was holding by a Chinese character, with red clothes. The character was on the holding above his head the paddle and he was running to not allow ...
5 votes
2 answers
125 views

Is FDISK /MBR really undocumented, and why?

Everything I've found so far claims /mbr is undocumented. Issuing the command fdisk /?on MS-DOS 6.22 gives no help so I assume there are no command line switches for fdisk. However this raises another ...
7 votes
3 answers
1k views

What is the purpose of the M1 pin on a Z80

I've been looking through bits of documentation about the (sadly recently discontinued) Z80 processor and the machines people have built with it. One thing I noticed is pin 27, called "M1", ...
2 votes
0 answers
157 views

Physical server with LED display on case, possibly programmable

Sometime in the 2000s I was in the server room of a customer site. This was still in the days of largely on-premise, not necessarily rack-mounted server boxes. A guy from their hardware vendor was ...
3 votes
1 answer
124 views

Commodore 128 bottom row of keys work with different shift keys

I have been playing with a Commodore 128 that I picked up but I have noticed one, what I would call, weird keyboard problem(?). If I an on the bottom row of the keyboard every other key works with a ...
6 votes
0 answers
240 views

Why does the boot-up screen for Cruis'n USA (arcade version) display this strange text?

(I originally asked this in the "gaming"/Arqade section. However, it was suggested by a commenter that I should instead migrate it here. Since I don't know how one "migrates" a ...
23 votes
6 answers
4k views

How can I reverse-engineer the game Wizardry (1981) for PC, based on UCSD Pascal?

I am looking at the files included with the 1981 game Wizardry. The particular version I have is from a 1998 re-release, but I do not know if the binary is still the original 1981 release. My ...
0 votes
2 answers
239 views

DEC's "decimal ASCII"?

I'm reading some older FOCAL documents and see references to things like... SETS X TO THE DECIMAL ASCII CODE OF THE INPUT CHARACTER A bit later there is a table of these codes, and unless I am not ...
2 votes
1 answer
138 views

Connecting the PHI2 pins on W65C22 [closed]

A year ago, I started designing my own 8-bit CPU with discrete transistors (I know this is a crazy goal, but I'm mostly doing it to learn). Now before I order everything for my CPU, I created a PCB ...
14 votes
3 answers
2k views

Were there 3D accelerators built on discrete logic?

I wonder if there were 3D accelerators (that is, a device that calculates rotations, scaling, texturing, etc. for 3D points) built on discrete logic (7400 series, most likely its fastest variants, ...
4 votes
0 answers
219 views

Looking for early examples of extended precision by interpretation

The other day I came across a clever way of implementing variable-length extended precision, dated 1967 (on the BESM-6, apparently as part of the system software available at the time of introduction ...
30 votes
2 answers
12k views

Looking for PC graphics demo software from the early 90s called "Unreal"

Back in the early 90's I remember downloading a graphics demo called, I think, "Unreal". This was on DOS on a standard PC and probably downloaded from a BBS. Identifying information: It ran for ...
7 votes
1 answer
323 views

A demoscene production from mid-2000s featuring four seasons animation

I recall seeing a PC demo - meaning an executable program demonstrating various graphics and sound effects - in mid-2000s (does this count as sufficiently retro?) that featured animations of the four ...
4 votes
0 answers
208 views

Is the source code of Alan Dain Sample's m5 macro processor lost?

I've recently come across the User's Guide to the M5 Macro Language by Alan Dain Samples. The guide says that the source code is available at thor.ece.uc.edu:pub/dain/m5. However, this seems not be ...
17 votes
1 answer
707 views

What capabilities did the Mark I Perceptron demonstrate?

The Mark I Perceptron, developed by Frank Rosenblatt in 1958, was a pioneering supervised image classification learning system. Many articles explain the mathematics behind it, and its shortcomings, ...
0 votes
0 answers
103 views

Where can I get 16K x 1 DRAM in ZIP package? [closed]

Where can I get 16K x 1 DRAM in ZIP package which I need for fixing an old device?
18 votes
6 answers
5k views

How did the `long` and `short` integer types originate in C?

I was wondering why C has the long and short integer type in addition to the plain int, and came across the following quote in the C99 Rationale (thanks to this answer here): [...] In the 1970s, 16-...
3 votes
1 answer
259 views

Why didn't Commodore run the 6502 at 2 MHz? [closed]

The Atari 800, in 1979, ran the 6502 at 1.79 MHz. That rounds to 2, and was presumably a 6502A rated for 2 MHz, underclocked. Why did Commodore keep running their 6502 computers at 1 MHz, even the 64 ...
13 votes
3 answers
2k views

Why was the Hobbit microcomputer withdrawn from the UK market?

The Hobbit is a Soviet computer which was built to be compatible with the ZX Spectrum, but with some extensions. For example it has more memory and can run CP/M. The Hobbit had favourable reviews in ...
7 votes
1 answer
562 views

What was "Mac SLM" or "ASLM"?

While looking through a very old codebase, I found some preprocessor defines and comments referring to something called "Mac SLM" or "ASLM". From the context, it appears to have ...
12 votes
2 answers
2k views

Are .COM executable binaries real mode or protected mode?

Windows and DOS binary executable files with the .EXE extension have an MZ header in them and nowadays also a PE header. But before these there used to also be .COM binary executable files and they ...
5 votes
1 answer
890 views

Why did the UNIVAC 1100-series Exec-8 O/S call the @ character "master space?"

It was used as a sentinel character in card images. It distinguished job control commands from data. But why the strange name?
-3 votes
0 answers
132 views

Was there a CGA video projector? [closed]

Was there an EGA projector? I wrote 3D software for both, but the customer demo was on a teeny monitor in a big conference room.
11 votes
6 answers
2k views

Did the Algol 68 standard allow a procedure to be called before its declaration?

In Algol 68, is it legal to say this? proc even = (int x) bool: (x = 0 | true | odd(x – 1)); proc odd = (int x) bool: (x = 0 | false | even(x – 1)); Forward references in structures are used in the ...
37 votes
4 answers
6k views

I buy retrocomputing devices, but they set my allergies off. Any advice on sanitizing new acquisitions?

I have had allergies in the past, mold, grass, and other causes of hay fever, also dust and cigarette smoke. I like getting old 8 bit systems, untested, and getting them to work. So far mostly for my ...
6 votes
1 answer
986 views

BIOS support for 286 Protected Mode

Did BIOS on 286 systems provide support for the Protected Mode? On a 386, the BIOS can be fairly easily accessed from protected mode using the Virtual 86 mode, but since 286 did not officially support ...
16 votes
2 answers
4k views

Did the NES CPU save die area by omitting BCD?

The NES CPU was a copy of the 6502 with the BCD circuitry removed. As I understand it, this modification was motivated by a theory that BCD was the only part of the 6502 that was actually patented, so ...
7 votes
1 answer
663 views

Which computer first used stored characters (shape selector) and character bit patterns in the same memory

On the Commodore VIC-20, the VIC chip alternates between cycles where it fetches a byte from screen memory that identifies a character (and also a nybble from color memory), and cycles where it ...
13 votes
7 answers
4k views

Has anyone ever made a quiet floppy drive?

The sound of a floppy drive is iconic. It is burned into the memory of all people in a certain age group. Some smarter ones even made music with them. But was there ever any effort to quiet them down? ...
4 votes
1 answer
259 views

My Amiga 500 "Enter" and "Return" keys wont work... possible causes?

I recently bought an almost working Amiga 500. When I got the unit in, I found that it mostly worked, the floppy drive spindle needed greasing, and the ram expansion just needed re-seating... but ...
8 votes
1 answer
2k views

Why was the SNES color gamut RGB?

The SNES color gamut is 15-bit RGB. On the face of it, that makes sense for a 16-bit machine. But. The color generators on some earlier machines like the Atari 2600, Commodore 64, NES, were not ...
16 votes
5 answers
4k views

Why was the 1540 a computer in its own right?

The Commodore 1540 disk drive, along with its better-known successor the 1541, is a computer in its own right, with its own 6502 CPU. Why was it designed like that? It adds significant cost to the ...
10 votes
2 answers
1k views

VT420: How can the five local function keys stop working?

I've got a 1989-issue VT420 terminal I used to use as a secondary console for my Linux machine. After a couple of years, I tried to bring it back to life. After switching it on, the well-known line ...
5 votes
1 answer
518 views

Where can one find "the Puzzle benchmark" from Hennessy’s MIPS paper?

I'm reading Hennessy's original MIPS paper. At the end, it includes estimated performance using "The Puzzle benchmark". The reference for this reads: Baskett, F., "Puzzle: an informal ...
10 votes
1 answer
1k views

Did any Famicom game use microphone for random seed?

So I know most common way to generate pseudo-random numbers on Famicom or NES is linear feedback shift-register. However... It came to my mind - Famicom controller has a microphone. Did any game ever ...
0 votes
0 answers
111 views

SATA to ATX 1.0&1.2 6-pin CPU AUX adapter (old AT power connector, AUXPWR, EAUXPWR) [closed]

I was thinking to create an adapter for this old connector using a SATA power cable and extension. I've harvested the 6 pin connector from an old Pentium 4 PSU, so I just want to splice it on the SATA ...
3 votes
3 answers
357 views

Were jailbars inevitable from VIC-II analog output?

I just watched an interesting video on the imperfections of video output on the Commodore 64. Among other things, he seems to be saying the commonly observed 'jail bars' effect is a result of other ...
7 votes
0 answers
218 views

The works of Frontier Manufacturing

Having spent the last however many decades believing Commodore Semiconductor Group was a simple rename of MOS Technology, I just watched a video – quite interesting in its own right – which casually ...
3 votes
0 answers
261 views

What process node enabled the 6502 to reach 2 MHz? [duplicate]

The original version of the 6502 was rated for 1 MHz, but before the end of the decade, the CPU was available in a 2 MHz version. Presumably what changed was Dennard scaling: make the transistors ...
15 votes
2 answers
666 views

Why did Acorn use the 6502?

It is an interesting quirk of the British microcomputer industry, that the main vendor of cheap microcomputers, Sinclair, used the better, more expensive CPU (Z80), whereas the main vendor of better, ...
29 votes
3 answers
11k views

How does the Gameboy Link Cable work?

I've been looking into implementing Gameboy Link Cable compatibility into Bizhawk (which does not support it yet) using Lua. The problem is that I can't find any mention of how it works online. I ...
2 votes
0 answers
243 views

What is this PSU connector? Compaq Portable motherboard

I've lost the PSU wiring harness to my Compaq Portable motherboard in a move and I'm trying to figure out what connector this is. Here's a picture with some AT-era Molex connectors for perspective. ...
11 votes
1 answer
395 views

What was the 6-bit length instruction(s) in the Intel iAPX 432?

The iAPX 432 was arguably the most complex processor architecture ever and a commercial failure for Intel. It was a stack machine with no visible general-purpose registers. It had hardware support ...
3 votes
2 answers
332 views

NES vs SMS ROM speed

The NES used a 6502-derived CPU at 1.79 MHz. The Sega Master System used a Z80 at 3.58 MHz. How did they differ in terms of what speed grade ROM they required in their respective cartridges? I know it'...
9 votes
2 answers
530 views

How did the PL/I designers not understand environments?

In Charles Lindsey's “A browse through some early bulletins”, he mentions (regarding Knuth's Man Or Boy test): As a postcript to this whole episode, it may be noted that a couple of years later Bekic ...
2 votes
1 answer
217 views

Printztronic on modern TV

I have been provided with a Printztronic Videosport 800 to try and get working. New batteries and plugged in via COAX triggers a TV response, but I only have a couple of smart TVs which are not easy ...
25 votes
3 answers
3k views

Why does CP/M use CALL 0005h for its syscalls?

CP/M, the operating system for Intel 8080 and Z80 (and others as well, but later) used to call 0005h for syscalls. The application would load the syscall number into a specific register (I think it ...
19 votes
3 answers
3k views

What terminal did David connect to his IMSAI 8080?

Since it seems that we are now accepting questions to identify-this-peripheral from a movie, we might as well address the quintessential Retrocomputing movie... What terminal is David using at home in ...
2 votes
1 answer
173 views

When were the late 70s FCC regulations introduced?

According to https://en.wikipedia.org/wiki/TI-99/4A Through the development period, several companies attempting to enter the home computer market were faced with significant pushback from the ...
27 votes
4 answers
4k views

Why did the Atari 800 designers choose such a radical system design?

The physical system design of the Atari 800 was pretty radical, when compared to the 3 other canonical home computer designs of the late-1970s: TRS-80 Model 1, PET, and Apple ][. As the photo of the ...

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