All Questions

I have a Sharp Super Scientific EL-9000 calculator (that used to be my mom's back in the day) which came with a Korean manual. I am a Korean American, and I can't understand the manual well. Does ...

The TECO editor, (originally Tape Editor and COrrector, later Text Editor...) found in some form on just about every computer and operating system DEC ever made, provides variables in which you can ...

I'm trying to get Programming Languages Through The Years over on the Code Golf site going again. The Wikipedia article that the challenge has been working from only lists COMIT for 1961, and calling ...

Furthering my reading of MS BASIC and Woz's FP code and comparing the two leads to another question specific to the 6502... From what I can see looking over the 6502 instruction guides, it appears ...

The Commodore 128 had 2 CPUs, 2 video graphic chips, and 2 I/O systems/chips. It had 3 modi: Commodore 64 mode, Commodore 128 mode and CP/M. The first shared one of each CPU/chip, the CP/M mode the ...

There has been several implementations of Forth that were running on, and targeting, the C64. Were there any commercial software releases (not throw-away hobby projects or in-house utilities) that ...

Browsing MS-DOS sources on GitHub, I often see mentions of XENIX: DOSSYM.ASM: ; XENIX calls all return error codes through AX. If an error occurred then the ; carry bit will be set and the ...

I have access to several meters of manuals of various sorts around CP/M on PCs and various bits on mainframes. These are earmarked to go after decades of "cannot dump that" heartbleed. Most are ...

The Amiga custom chip set, in its ECS and AGA versions, seems to contain some registers for what is called an "Ultra-HighRes/DUAL" mode: DFF078 SPRHDAT W Ext. logic UHRES sprite pointer and ...

As an example, say we have a DOS MZ EXE file that's around 20 KiB in size. The EXE header contains the value 0x1400 at offset 0x0A indicating that the program is requesting 5,120 paragraphs (or 80 KiB)...

I’m trying to make some graphics in Processing that look just like what I’d get on an Apple //e. I think this info is in rom disassembly but I can’t find anything by googling. Im also interested in ...

I read some related information in a SAM question but I want to know exactly how to write amplitudes directly to the DAC, sample by sample, like in a bytebeat formula. I understand it is possible on ...

IBM released the IBM 5150 Technical Reference manual in August, 1981, and included in it the fully commented source code listing for the BIOS. I find this odd for two reasons: IBM must have realized ...

Looking at the schematic and explanation of how the C64 joystick ports work, it seems clear that the stick direction and button lines (JOYA0, through JOYA3 for port 1 and JOYB0, through JOYB3 for port ...

Cannot find any documentation on this computer, need some help identifying it. I am pretty sure this is some kind of print server and the date on the parts is 1989.

I know that nowadays Tantalum is very common in computer components, specifically capacitors, due to its desirable electrical properties. I'm curious when it was first used specifically in the ...

On intel IAPX 80286, as I recall from experience, the undocumented - officially unassigned - "opcode" position 0xF1 was actually decoded as an instruction-prefix, thus counting for maximum allowed ...

Which programming system first introduced "destructuring" denoting accessing various parts of an object using some sort of pattern, and binding those parts to variables, like Common Lisp's ...

I am trying to reverse engineer an old Wolf3D style Dos game named "Nitemare 3D". I can get a raycasting engine with directional sprites running pretty easily using SDL2, but I have no experience with ...

I remember in the 90s, there existed a Unix command line utility named smiley that decoded emoticons. A sample use would be like this (the output is likely not the exact output the program gave): $ ...

I was always under the impression that MS BASIC implemented NEXT by pushing the address of the FOR on the stack. So convinced that when I read the source code I assumed CURLIN had to be referring to ...

From the Atari SM124 Monochrome Monitor Service Manual, I get that the video signal timing for one line is 20µs. With the horizontal resolution of 640 pixels, this gives a 31.25ns pixel clock. Using ...

I am doing a design based on the Motorola 68332 MCU made for embedded applications, which is based on the CPU32 core. The CPU32 core is very similar to the 680x0 CPUs, but there are some subtle ...

Didn't find anything with a search and need to replace the tube due to it being severely burnt in. [] []

I know dual socket motherboards were around in the 90's before Intel released the Core series. And SMP hardware and operating systems have been around earlier than the PC platform of course. ...

Trying to recover data from Conner CP341 HDD i took from an old Compaq Portable III. The data is important enough to go through the effort of recovering it, and i would like to do this myself (rather ...

I've got an early 486 motherboard that doesn't seem to have a manufacturer name or FCC number on it and I'm having trouble identifying it. I've placed some photos of the motherboard in this Imgur ...

I've been following Ben Eater's series of videos about designing a small computer from discrete logic gates, I'm curious if there is a similar tutorial/book/reference for building a stack computer. I ...

Is it true that ctrl+alt+del only became a thing because IBM would not build Bill Gates a computer with a button specifically for the task manager? Making it so that Microsoft had to develop a ...

Most of the history of Commodore in personal computers took place while East and West Germany were divided, and Commodore maintained a significant corporate presence in West Germany. While I believe ...

I was reading a bit about the 'Hacker Manifesto' written by Loyd 'The Mentor' Blakenship and was also reading about the hacker group 'Legion of Doom' and was wondering what influence these groups / ...

It's pretty well documented how to get the 286 from real mode to its 16-bit protected mode. It's also widely stated that the 286 had no officially supported way of going back from protected mode into ...

I was recently looking at some documentation for programming the Apple Lisa: https://lisa.sunder.net/LOS_Reference.pdf and I was surprised how advanced it was for the time. It had a lot of features ...

So far I've figured out that means something about the ram bit I haven't been able to figure out what the problem is Edit: video link

Anyone heard of 'something like' EDITLN or EDITLINE or LINEDIT statement in BASIC for editing lines of a program's own code while executing ? I seem to remember a statement that was spelled '...

Most modern platforms have pretty well-defined file formats; e.g. Windows uses PE, Linux and BSD - ELF (previously a.out), macOS - Mach-O, AIX - XCOFF and so on. What were (are?) common executable ...

A useful way to do concurrent programming is, say, a Compare-And-Swap instruction, which really is two operations, executed one after the other, atomically. This was available on the IBM 370 and on ...

Programs like The Beagle Compiler allow AppleSoft BASIC or other Apple II BASIC variants to be compiled. How do the compilers compare in terms of speed, compatibility, and features?

I know the Atari's FP package used BCD for rather dubious reasons, but does anyone know of other examples of basic "operating system" level code on common platforms that used BCD? I suspect BCD was ...

In his account of the history of the Apollo Guidance Computer, Don Eyles describes the role of a parity bit as follows (p. 80): ... if one of those hair thin wires in our woven core-rope memory ...

The SPI four-wire serial bus is a very common interface between chips and other small devices these days, but was originally developed by Motorola in the mid-1980s. What were the first Motorola and ...

First, a bit of context. I wrote an interactive disassembler for 6502 code that, among other things, attempts to identify ASCII strings automatically. Appropriate source code for different assemblers ...

The three official video modes described on the CPC wiki are all bitmap modes, and this page mentions that the "screen is bitmapped. You must draw/erase your own sprites and text." So what was the ...

According to Wikipedia, The Motorola 6800 was released in 1974. Between that and the release of the 6809 in 1979 (or 1978?) there was at least one other 6800-series CPU released, the 6802 ...

I'm currently using [this version of f9dasm] on Linux to disassemble a moderately large Motorola 6800 program (Altair 680 Basic, about 8 KB in size). f9dasm isn't too bad, but I'd prefer to use ...

Quoting a comment from this question: Why did Windows 95 crash the whole system but newer Windows only crashed programs? "A lot of effort has gone into automatically enforcing that drivers are more ...

As far as I know, the popular low-end home computers in the UK around the mid-1980s were the Sinclair ZX-Spectrum ("Speccy") and the Commodore C64. I know the BBC micro also had a following, but my ...

Having only a single index register and no addressing mode indexing against 16-bit addresses in memory seems to have been widely considered a primary reason that the Motorola 6800 fared poorly in ...

This is a followup to Could the Intel 8086 CPU have many segments in memory of the same type? In the event of a hardware interrupt or user interrupt through the INT instruction, was there a risk that ...

Example situation. You are using a program in Windows 95 and screen goes blue only for you to restart the whole computer You are using a program in Windows 7 and the program stops responding only to ...