All Questions

1
vote
1answer
205 views

What don't I understand about this LR35902 code?

The question you are now reading is about a comment on this question, about overflow bugs in some Pokemon game. A comment on that question says: It was Game Freak's first project. They just were ...
25
votes
8answers
13k views

Did a shuttle launch take most of the world's computing power?

The 1998 movie "Armageddon" depicts two Space Shuttles launching simultaneously. I read some expert say that "There isn't enough computing power in the world to launch two shuttles at the same time". ...
5
votes
1answer
241 views

Commodore Plus/4 60671 bytes free - how?

It is widely known that, while the Commodore 64 did indeed provide 64K of RAM for machine code programs, only 38K was usable from BASIC; this was because bank switching was needed to get at the rest, ...
15
votes
3answers
1k views

Commodore BASIC and binary floating point precision

I am mildly curious that though the 6502 provides BCD arithmetic which would be useful for implementing decimal floating point, Commodore BASIC uses, like all (?) Micro-Soft BASIC, binary floating ...
27
votes
1answer
1k views

Did Windows NT 4 emulate x86 on non-Intel platforms?

I've been trying to find more information about non-Intel versions of Windows NT regarding x86 emulation but found very little about it. There is one sentence about it in the Wikipedia page but the ...
50
votes
12answers
10k views

How big is a mainframe?

If you read about the history of computing, you'll hear how the first computers were "huge". You will often come across assertions that in the early days of commercial computing, a single computer ...
3
votes
1answer
164 views

Logitech drivers from Windows 95 Installer on the actual disk

I'm attempting something that might seem crazy but I got stuck at the end. I am installing Windows 95, on a flash drive, using a PC with modern hardware (Not a virtual machine!). I got around the ...
3
votes
3answers
174 views

How to image a RLL or MFM hard disk on an XT class PC

I have an old XT clone which is fitted with a Seagate ST-238R RLL hard disk and an ST11R hard disk controller card. I have recently revived this old machine and it all appears to be working still. I'...
6
votes
4answers
563 views

Amiga floppy disks and GCR vs MFM

According to https://en.wikipedia.org/wiki/Group_coded_recording the Commodore 1541 disk drive used a particularly efficient GCR encoding scheme to cram 170K onto the same 5.25" disks that in an Apple ...
-1
votes
6answers
587 views

Can you compile 6502 assembly into a stand alone application

6502 assembly is a language meant for humans to compile it themselves, not compilers. Its an older Assembly that powered the olden days of computing and consoles such as the NES and Atari 2600. I want ...
-3
votes
4answers
249 views

Operating systems which have non-x86 instruction set architecture [closed]

What are the most famous operating systems for non-x86 computers? I mean, most famous OS which have different instruction set architecture. Background (to better understand my task): I ask this ...
18
votes
7answers
3k views

Why not constant linear velocity floppies?

The outer tracks of a disk are longer than the inner tracks, and could therefore potentially hold more data. Constant angular velocity puts the same number of bits on every track, which wastes much of ...
4
votes
2answers
269 views

C116 vs C64 cost

The Commodore 116 was the start of the ill-fated TED line of 8-bit computers, which sold poorly (for several reasons, particularly including lack of compatibility with the Commodore 64) until they ...
13
votes
0answers
262 views

Why did Apple remove booting from external drives in later IIc ROM versions?

Apple II computers don't come with DOS in ROM, but rather need to boot from a floppy disk to make the disk drives usable. The IIc was the first Apple II that came with a built-in disk drive, so ...
4
votes
3answers
818 views

Parallel to serial conversion

Two very common connectors used in the eighties were the Centronics parallel port (particularly used for printers) and the RS-232 serial port (particularly used for mice and modems). Suppose you have ...
3
votes
5answers
312 views

What happens when a terminal (like a VT100) is connected to a computer?

I'm wondering what's the sequence of actions when a terminal (like a VT100) is plugged into a serial port of a computer? Especially, how the connection of this terminal is detected, and how the ...
1
vote
1answer
116 views

How to add Final Cartridge III to VICE Emulator

How do I properly add Final Cartridge III to VICE Emulator? In the file menu, VICE has an item Attach cartridge image... which splits up into CRT Image but also a list of several cartridges, among ...
80
votes
20answers
17k views

Have programming languages driven hardware development?

Programming language development has been influenced by hardware design. One example from this answer mentions how C pointers were, at least in part, influenced by the design of the PDP-11. Has the ...
2
votes
2answers
197 views

How do Bulletin Board Systems work? [closed]

Recently, I've been very interested in old-school bulletin board systems (BBS) from the 90s. I'm interested in building my own (mostly as just a fun challenge), but to be honest, I'm not totally sure ...
6
votes
3answers
182 views

Why do we need to acknowledge the interrupt from VIC-II?

A page on how to do raster interrupts includes the following code Irq: LDA #7 STA $D020 ; Turn screen frame yellow LDX #90 Pause: DEX BNE Pause ; Empty loop that "...
21
votes
8answers
3k views

Did terminals (e.g. VT100) require a terminal driver on the host computer?

I'm wondering if terminals (like, e.g. the VT100) required the installation of a driver on the host system in order to work with that host? I looked at the documentation of the VT102, and there is ...
16
votes
7answers
4k views

Why didn't PostScript eliminate the need for printer drivers?

In the days of dot matrix printers connected by RS-232 or the IBM/Centronics parallel port, each with its own quirky set of commands, it's obvious why printer drivers were a necessary and important ...
2
votes
1answer
182 views

Accessing DOS USB Drive

I am setting up a new development computer with FreeDOS and can boot off the SATA or USB drive. This is my first new computer with sophisticated UEFI (I have CMS enabled). If I boot from the USB I ...
5
votes
4answers
305 views

Can escape sequences be entered directly from keyboard to terminal for VT100 and similar?

TL;DR: In video terminals, like the VT100, can control characters and escape sequences only be sent by an application from the host computer to the terminal? Or can they also be sent directly by the ...
1
vote
2answers
239 views

When did game consoles acquire battery-backed clocks?

The importance of a desktop PC knowing the current time could be debated, but it is clear IBM felt it to be important, for the IBM PC typically prompts the user to supply it on boot. Given that, the ...
1
vote
5answers
378 views

Are there any old and nowadays active Operating Systems which has only BASIC Programming Language?

Some old Operating Systems I hear have only BASIC Programming Language. Are there any active and old operating systems which includes only BASIC Programming Language?
4
votes
2answers
349 views

Why does Sinclair BASIC have two formats for storing numbers in the same structure?

The ZX Spectrum has two formats for storing numbers, both 40 bits, or five bytes. The first is a floating point format, which consists of one exponent byte, and four mantissa bytes. The first bit of ...
6
votes
1answer
353 views

How did the C64 interface tape drives?

How did the C64 interface tape drives? I'm aware that the external interface was basically a audio input - but how was this audio converted into digital data, and how was it loaded into RAM and ...
2
votes
1answer
133 views

How to read old 3.5" Macintosh formatted floppies on a MacBookPro

I have connected a USB external floppy drive to my Macbook Pro (OSX El Capitan). I am unable to "view" the external drive, and hence unable to access the floppy content. I have inserted a floppy, ...
3
votes
2answers
491 views

When and why did tape recorders acquire a “remote” input?

This entirely-typical-of-the-era (other than mysteriously missing its EAR socket) tape recorder from 1984 was the "standard" type of tape deck for home computer data storage in the UK. They could be ...
2
votes
1answer
120 views

Why didn't Famicom games use the Konami SCC for expansion audio?

There were a handful of Konami games on the Famicom that had additional sound chips (VRC6, VRC7, etc.) to enhance the audio of the games they were used in. Considering that the Famicom got many Konami ...
1
vote
2answers
173 views

Can DOS 6.22 recognize more than 504MB when the BIOS only supports CHS?

My CMOS setup correctly recognizes the geometry of the drive, (but does not support LBA). And FDISK in DOS 6.22 only recognizes 504MB. FDISK even shows the size of the primary partition as roughly ...
2
votes
1answer
139 views

A game where you could sell body parts for cash

Ages ago I played a scifi game on the Apple IIgs where you could sell body parts for cash. The game involved travel between planets and selling parts of yourself was a last ditch option to raise money ...
1
vote
1answer
139 views

How was the modem MNP protocol implemented in software?

When first modems for PCs started to appear in the USSR in late 1980s, they usually were in the form of an ISA card, and supported a bare minimum of the Hayes AT commands. Given the quality of Soviet ...
1
vote
1answer
98 views

Is it possible to switch the interrupt source of the C64 to VIC without changing the IRQ routine?

The ROM IRQ routine at $EA31 is usually trigggered by the timer interrupt 60 times a second. Is it possible to switch the interrupt source to VIC and still use the same routine? If yes, which memory ...
15
votes
4answers
4k views

Why did 3.5" floppies win? [duplicate]

It's an open question whether desktops would've kept using 5.25" until the end of the floppy era, but laptops meant something smaller was going to be introduced; that much was essentially ...
48
votes
11answers
13k views

Why did trackballs disappear?

For a desktop computer, a mouse is a great pointing device. For a laptop if you don't want an extra device to keep track of, you need an alternative. The options I'm aware of: NubLow-tech, cheap, ...
0
votes
2answers
201 views

Does anyone have an x86 EGA draw pixel routine?

So far, I have gotten by with using the BIOS draw-pixel routine here: http://stanislavs.org/helppc/int_10-c.html This works of course, but I can't imagine that commercial games used this BIOS call as ...
1
vote
4answers
157 views

What's the pitfalls when trying to connect a new SCSI hard drive to an old SCSI bus?

Problem I have a couple of old computers. Some of them have a SCSI-1 or SCSI-2 interface over an internal 50 pin IDC connector or an external DB25. Now I want to connect something to them, in ...
24
votes
3answers
5k views

386SX, NES and how much did data lines really cost anyway?

In 1988, Intel introduced the 80386SX, most often referred to as the 386SX, a cut-down version of the 80386 with a 16-bit data bus mainly intended for lower-cost PCs aimed at the home, educational, ...
3
votes
2answers
200 views

Why not make more use of the video generation logic?

The Apple II is famously built around its video generator. Conveniently, addresses are generated which scan all of the video memory and somehow spits the contents onto the screen. Its occurred to me ...
11
votes
1answer
192 views

Could suitably-written Apple-I software force bytes into the display shift register, and do modern recreations emulate that?

The original Apple I didn't use RAM to hold the contents of the display, but instead used a group of six 1024-bit shift registers to hold the display contents and a seventh 1024-bit shift register to ...
2
votes
3answers
322 views

What do the numbers on the punch cards mean?

Does anyone know what is the meaning of the numbers in punch cards? I need an example of any language, it's important for me to understand which information could be manipulated.
1
vote
1answer
441 views

Wider tower cases

Desktop computers have been in tower cases for a long time; in some cases since the eighties, per When did the tower form factor appear and when did it become popular? The form of tower cases has ...
26
votes
3answers
5k views

Why separate cursor keys?

The original IBM PC keyboard didn't have separate cursor keys; the numeric keypad doubled as such. It wasn't long, however, until a new keyboard was introduced that did have separate cursor keys (so ...
9
votes
3answers
738 views

IBM PC expansion card latency

In the IBM PC and early successors and compatibles, it was commonplace for most of the computer's memory to be on cards in general expansion slots. (e.g. the original IBM PC could take 64K on the ...
5
votes
2answers
186 views

How to exactly sync to the raster line for a vertical raster split?

Motivated by Wilson's question Can a Commodore 64 use two screenmodes on one scanline? I tried to implement a simple example that polls the beginning of a rasterline and then switches the screen mode ...
2
votes
1answer
96 views

What is the 26-pin D-sub (DA-26) connector used for on the Media Vision Pro AudioSpectrum 16 Patch Panel?

My dad has this audio interface from the 90s called the Media Vision Pro AudioSpectrum 16 Patch Panel, but unfortunately doesn't have the manual. From my research, it appears that this panel was used ...
0
votes
1answer
130 views

How viable is a universal PC parallel/serial connected CP/M disk controller/drive?

I had an idea and wanted to hear if there are any major technical obstacles. Imagine any vintage computer with either a serial port or a parallel port. The vintage computer is connected via that ...
8
votes
1answer
197 views

Were any PDP-11 systems with Corita Kent side-panels actually sold?

Somewhere around 1980, I heard about PDP-11 systems that had side-panels designed by Corita Kent (a nun and pop artist, who amongst other things designed a stamp for the US post office, and gas ...

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