All Questions

The 8087 has instructions FPTAN and FPATAN, which are Partial Tangent and Partial Arctangent. The "partial" is presumably is to do with the range of the operands. For FPTAN the operand must be less ...

The APL language used a unique set of characters, and additionally allowed overstriking of some characters on the terminal to form characters that were used in the language. When an APL workspace was ...

This question addressed the question of APL overstrikes on printing terminals. However, IBM also had 3270 video display terminals that supported APL, as well, and those, too, handled overstriking. How?...

Chapter 3 of the Apple II Reference Manual describes the machine-language Monitor. On page 41 it describes certain remembered locations: The Monitor remembers the addresses of up to five locations. ...

Inspired by comments on the previous question Is it true that Netscape Navigator eventually became Mozilla Firefox? (Answer: Yes). In 1998, Netscape released a large amount of their existing source ...

The CHAR command in Commodore BASIC 7.0 on the Commodore 128 allows printing a text at a given position on the screen. Other than the PRINT command, CHAR also works in Hires graphics mode. Since the ...

A BASIC program that was deleted with NEW or after a reset can be restored on Commodore computers as long as no new programs are entered or loaded (or the computer is powered off). For the C64, the ...

I am trying to identify a World War 2 European theater PC game, which I used to play on a Windows 95 PC, but probably predates Windows 95. The one thing that really stands out in my memory is that if ...

Is it really the case that Mozilla Firefox is a modern day version of Netscape Navigator?

How exactly did Microsoft reverse engineer Brendan Eich's JavaScript, call it something else and not get a massive lawsuit in the aftermath? I understand this was a long time ago but I still wonder ...

I use DOSBOX with 8086x assembly and I want to add to my game project background music with MIDI

Modern x86 processors have an infinity control bit on the x87 FPU control register. This is bit 12 and it enables processing of infinity values in a manner that is compatible with the 80287 ...

I have an emulator up and running and access to the asimov ftp site, and I want to learn how to program assembly language on the Apple IIe. What assembler should I use (Merlin? LISA?) and what book or ...

There's a fairly common program for DOS 3.3 on the Apple II that clears the screen, prints a catalog of the disk, and allows you to select files by letter to run or do other operations on them. This ...

I have an INLRetro cart dumper. The software for the device is incomplete and in beta form. I've been able to dump Tetris and it works (because it's ROM fits into bank 0). When I attempt to dump ...

I'm building a simple Z80 breadboard computer for my hobby. In this question I use Z80 as an example, but I think this may apply to many CPUs that allow for bus sharing. The problem is as follows. ...

How do you access more memory (above the 1MB) in DOS if the 640KB of conventional memory are not enough? I have read a lot about this, but I couldn't figure out how to do this in actual code. Is ...

Pretty much the title - what was the first GPU that reduced clock speeds when it started to overheat instead of simply locking up? Bonus points for first Intel and AMD CPUs too.

I found my old atari 130XE, full of dust. I have the power supply but I don't have connection cables and controls. I've searched in eBay, Amazon and such for controls and there are plenty of them. My ...

We are talking about a hardware (and not software over hardware, as for example in some games on the SNES console) tile engine with multi-overlapping rectangular (rather than square, when the image ...

I was delighted to learn there is an integrated toolchain for Rust development that supports the Nintendo 64. According to the documentation: For copyright purposes, the IPL3 binary is not included ...

Commodore produced a number of different floppy diskette drive units, both 8" and 5.25", over the course of its history. Can someone provide a chronological list of the drives, their release dates, ...

Nanodata was a Buffalo, New York company that was formed in 1971 and seems to have sold its first products in 1973. They filed for bankruptcy in 1982, though they may have carried on business for a ...

Related to question What is the best way to obtain old versions of MS-DOS and Windows? When will the copyrights on various versions of Windows and DOS expire? Once they expire I presume one could ...

I've recently purchased a used Nintendo Wii console. It came with two Wiimote units, one of which seems to be slightly defective. I notice the defect when I try to use it as a "steering wheel" for ...

In the operating system (DOS) of IBM PCs, newlines were represented by a carriage return (CR) character, followed by a line feed (LF) character. The motion of a printer or teletype receiving such a ...

Way back in the late 80s there was a game that centered around maintaining and running a power station for the local town. It wasnt particually complex or graphic.. just fun. On the lhs of the screen ...

I just saw this button in the Computer History Museum, and I'm wondering what is the context? Context removed, "Is MS DOS a feminist?" is about the most non-sequitur thing I've seen.

Anyone who has studied Unicode and is honest will admit that UTF-16 was kind of a mistake. It was born from the early assumption that 16 bits would be enough for all of Unicode. Then a hack was ...

Dave Cutler is well known for his contributions to operating systems, having led the effort on VAX VMS at DEC and Windows NT at Microsoft. According to his Wikipedia page, he is also known for ...

The Apple IIe was designed to be timing-compatible with the Apple II+ so that timing-depndent software (such games and copy-protection systems) and hardware designed for the Apple II and II+ would, ...

I have a PC with an Intel P133 (133 MHz). The motherboard (PcPartner MB520NH) only allows for it to be slowed down to 75 MHz at the least via jumper settings, but no lower. Yet the PC's case has ...

The ZX Spectrum BASIC doesn't (ordinarily) let you print on lines 23 and 24 to allow for user input. Is there a way around this? I found a fairly recent post that suggested I could POKE 16418,0 but ...

This question is based on a comment by Neil on another question regarding integer-multiplication: Do you have any citations for your claim that most MS-BASIC integer multiplication was done by ...

The Cray-1 has 12 segments arranged in a 270 degree arc. It also has 12 functional units, so is there one functional unit per segment? There were 1,662 modules in 113 varieties, but what is a module? ...

I've recently become interested in the original Teddy Ruxpin that operated by playing 8-track cassette tapes. The 8 channels on the tape were used in a creative way to ensure that Teddy's animation ...

The Apollo Guidance Computer had its code stored in six modules that held 6 kwords of storage each, and the design of each module was such that changing even a single bit after construction would have ...

I have recently fixed an old IBM Clone, which has an MFM hard drive. The PC booted up fine, but then I saw, that a few years back, I have deleted a few important files (probably by mistake). The ...

I recently got a SID chip (8580r5) for $35 and got it playing music. I was really happy about it. I hooked up a small amp chip to the 9V supply momentarily (it didn't work, I was building that part of ...

I've recently been teaching my 11 year old binary multiplication, which is on the UK maths syllabus at secondary school. We have used long multiplication, eg shift and add. This has made me wonder ...

I know Mame works with drivers for each game or hardware, and it checks for specific ROMs, and I guess it might check also for some checksum to verify the ROMs integrity. Is there some way you could ...

In this manual for the DEC CR11 card reader controller, the controller can deliver the card content to the PDP11 in either of two forms: Column binary: the 12 rows of hole/no-hole are delivered in ...

I have an original NES from England that I bought in the early 90s. I just found it again in the attic, and I want to hook it up and start playing it again. However, I now live in the USA and it's ...

I'm considering installing two graphics cards in my retro gaming setup (one AGP and one PCI) and was wondering if there are any drawbacks to doing so? The main things I'm thinking about are power ...

I have an Apple IIc with 128 KB of RAM, about half of which goes unused. Since the IIc has only one drive, it would be convenient to use some of that unused RAM as a RAM disk. I know that this is ...

The Unicode 13.0.0 release notes mention among the symbol additions: 214 graphic characters that provide compatibility with various home computers from the mid-1970s to the mid-1980s and with early ...

My understanding is the CPU clock speed on the Intel 8088 in the IBM PC was selected as 4.77 MHz to simplify the design of the system. This despite the 8088 coming in two versions - 5 MHz and 8 MHz. ...

I'm trying to compile a C program with z88dk for the ZX Spectrum. Using printf(), when the text hits the bottom line of the screen on line 24 the program stops executing until a key is pressed on the ...

I thought that punched cards already represent the code in binary since a hole means 0 and rest positions mean 1 on a punched card. But then I read that you could use punched cards to present the ...

Someone was recently selling an early MOS 6502 CPU on Ebay (date code 0277) in a ceramic package that had a couple of holes in it. You can see them clearly (under the tape, which presumably was not ...