All Questions

Filter by
Sorted by
Tagged with
1
vote
2answers
61 views

Arduino Uno (ATMega328) vs Motorola 68000/68010 [on hold]

Since ATMega328 is a microcontroller, and Motorola 68000/68010 is a CPU, we consider only the processor core - command execution speed, memory access speed, arithmetic speed, registers in RAM or CPU, ...
6
votes
2answers
505 views

GPU chip implementation on CPU - will it be faster? [on hold]

So, modern video cards include two devices - a video signal generator and a graphic accelerator. The first of them converts data from video memory into MDA / CGA / VGA / RCA / DVI / HDMI / etc format....
3
votes
1answer
74 views

What are examples of providing non-RST instructions for 8080 interrupts?

When a peripheral in an 8080 system generates an interrupt request and the 8080 acknowledges the interrupt, the peripheral is expected to put an instruction opcode on the data bus which the 8080 will ...
2
votes
0answers
97 views

Was the Music System for the Exidy Sorcerer as exceptional as I remember?

I am trying to remember about a bare-board sound card which plugged into the parallel port of an Exidy Sorcerer (circa 1980). The card and software ("Music System") was made by Arrington Software ...
6
votes
1answer
147 views

Digital PCB Plans for Retro Computers

I use software like Fritzing or Autodesk EAGLE to draw my Raspberry Pi or Arduino projects and was wondering if there is a source for PCB plans of for example an Amiga 500 in a format readable for ...
4
votes
0answers
110 views

Modern Alternative to Malvino's Digital Computer Electronics

For those who want to study retro computing in depth, starting by understanding 74xxx logic and CPU design is (IMHO), one of the best paths there is. Malvino's "Digital Computer Electronics" (DCE), ...
-2
votes
0answers
94 views

How to get old PC desktop games [on hold]

My parents changed their computer after many years (from Windows XP to Windows 10) and I'm trying to instal some old offline desktop games. I found solitaire and some card games, but they also want ...
8
votes
6answers
2k views

Is there any music source code for sound chips? [on hold]

I’ll clarify what I mean. The sound chip (c64's SID, spectrum's Yamaha, etc.) is connected either to the input / output port, which will be reserved for the sound chip, or directly to the CPU data bus....
12
votes
4answers
2k views

Do AT motherboards (286, 386, 486) really need -5V (besides redirecting it to ISA connectors)?

The power supply of my 386DX computer (an unknown brand M320 motherboard) is not trustworthy anymore, so I'm planning to use an ATX power supply, plus an ATX to AT adapter for P8-P9 connectors. The ...
85
votes
1answer
23k views

Why did MS-DOS applications built using Turbo Pascal fail to start with a division by zero error on faster systems?

On faster MS-DOS systems, it wasn't entirely uncommon for applications built using Borland's Turbo Pascal to fail to start, and (before exiting back to the command prompt) to report a division by zero ...
12
votes
2answers
693 views

Were there 486SX revisions without an FPU on the die?

I know that the 486SX had its FPU disabled, maybe by binning 486 CPUs into those with and without functioning FPUs. But did Intel eventually make a 486SX revision without an FPU on the die?
20
votes
5answers
3k views

What is the hex versus octal timeline?

When and why did hexadecimal representation become more common than octal for displaying and printing out multi-bit binary fields?
4
votes
2answers
140 views

Need circuit - manual step-by-step clock for 8086/8088

I finally bought a ceramic 8086-1 (from ebay, from China - I'm not sure that it is not fake chip) and 8284 (it make the necessary synchronization signal for the processor from the crystal). Now I ...
5
votes
2answers
395 views

How to setup a teletype to a unix shell

So, recently I've been researching old tech because I want to write some fiction about some typewriter that can access the command line(yep) that shows up in many youtube videos like This one. I want ...
0
votes
1answer
65 views

How do I examine and use the SWTBUG monitor ROM in the SIMH SWTP6800 simulator?

I'd like to examine (disassemble and memory dump) and run the SWTBUG monitor ROM in the SIMH SWTP6800 emulator, but I seem to be having difficulty getting the devices attached properly, or I'm lost in ...
3
votes
1answer
131 views

Could somebody remind me how to access the WAP browser on the Nokia N73?

From memory, the Nokia N73 had two web browsers; one WAP browser, and another, fully-functional HTML application. Would somebody be able to remind me what both of these options are labeled as when ...
3
votes
1answer
107 views

Sharp Super Scientific EL-9000 English Manual

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 ...
12
votes
1answer
234 views

Why were TECO variables called Q-registers?

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 ...
0
votes
1answer
211 views

What programming languages appeared in 1961?

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 ...
5
votes
4answers
441 views

6502: is BCD *fundamentally* the same performance as non-BCD?

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 ...
19
votes
4answers
3k views

What was the intention with the Commodore 128?

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 ...
9
votes
1answer
232 views

Commercial C64 software implemented in Forth?

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 ...
25
votes
4answers
3k views

What's the relationship betweeen MS-DOS and XENIX?

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 ...
49
votes
4answers
6k views

What should we do with manuals from the 80s?

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 ...
8
votes
3answers
312 views

What are the Ultra-Highres registers in ECS and AGA for?

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 ...
25
votes
1answer
2k views

Did DOS zero out the BSS area when it loaded a program?

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)...
6
votes
2answers
268 views

Where can I find the Applesoft line-drawing algorithm?

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 ...
3
votes
1answer
112 views

How to write directly to the Commodore 64 (or similar) DAC [duplicate]

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 ...
62
votes
8answers
15k views

Why did IBM make the PC BIOS source code public?

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 ...
3
votes
1answer
242 views

Did any devices use the Commodore 64 joystick ports as outputs or two-way communications ports?

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 ...
2
votes
1answer
147 views

Xerox 3700 Documentation?

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.
1
vote
3answers
236 views

When was Tantalum first used in computing?

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 ...
10
votes
3answers
585 views

0xF1 opcode-prefix on i80286

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 ...
4
votes
0answers
212 views

First use of “destructuring” in computing?

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 ...
2
votes
2answers
243 views

How can I extract game data from Nitemare 3D files?

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 ...
10
votes
1answer
287 views

Unix utility “smiley” to decode emoticons: Where to get it?

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): $ ...
4
votes
1answer
331 views

Why did MS BASIC use the line number for FOR loops?

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 ...
13
votes
2answers
550 views

Atari ST DRAM timing puzzle

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 ...
11
votes
1answer
981 views

Why was CPU32 core created, and how is it different from 680x0 CPU cores?

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 ...
1
vote
0answers
95 views

Identify Toshiba CRT

Didn't find anything with a search and need to replace the tube due to it being severely burnt in. [] []
13
votes
5answers
3k views

What was the first multiprocessor x86 motherboard?

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. ...
3
votes
3answers
224 views

Steps to recover data from Conner CP341

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 ...
0
votes
2answers
319 views

What 486 motherboard is this, with American Megatrends BIOS identifying is DPAQ-6156-043090-KF?

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 ...
4
votes
2answers
267 views

Reference material for building a DIY Stack Computer from Logic Gates

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 ...
25
votes
6answers
14k views

Is it true that control+alt+delete only became a thing because IBM would not build Bill Gates a computer with a task manager button?

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 ...
16
votes
1answer
1k views

What was the role of Commodore-West Germany?

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 ...
2
votes
0answers
117 views

What was the influence of the 'Legion of Doom' and the e-zine Phrack on early computer culture? [closed]

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 / ...
15
votes
3answers
2k views

How to switch an 80286 from protected to real mode?

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 ...
25
votes
1answer
403 views

Why were pipes removed from the Lisa?

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 ...
11
votes
1answer
2k views

3 beeps on a 486 computer with an American Megatrends bios?

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

15 30 50 per page