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35
votes
7answers
4k views

Why is the processor instruction called “move”, not “copy”?

Many processors have an instruction called "move" (sometimes spelled MOV) which copies data from one location (the "source") to another (the "destination") in registers and/or memory. It does not do ...
7
votes
4answers
1k views

Why does UNIX ed not have a prompt by default

The line editor ed in UNIX/Linux has a "command mode" and an "insert mode" and there is no visual way to tell which mode you are in. However, there is a -p option that causes it to display a prompt ...
4
votes
1answer
86 views

Using MAI DT4315A as a terminal for RaspberryPI or other linux system

I have an old MAI DT4315A that my company was going to throw out. I'd love to get it setup as a terminal for a linux based system or raspberry pi, just for fun. However, I've never completed anything ...
5
votes
1answer
87 views

Does the TELCOM program on the Tandy Model 100 support any Unix terminal–like control codes?

I've been connecting my Tandy Model 100 to a serial port on a Linux box via the TELCOM program with some success. The main downside is that in whatever the default terminfo/$TERM setting it gets, a ...
26
votes
2answers
9k views

Did the Windows 95 screensavers use hardware acceleration APIs?

The windows 95 is known for introducing a couple of classic screensavers including: Maze, Pipes and starfield among others. It looks like DirectX is a collection of multimedia APIs but for this ...
0
votes
1answer
138 views

Spider and snake in a square

In the game you were a spider which could run from one wall to the other. The snake could either destroy your net or you. If you reached another wall the room where snake could move got smaller. If ...
10
votes
2answers
2k views

Running DOS, Windows 3, and Windows 98 from one FAT32 partition?

I'd like to setup a Windows 98 SE system that boots into the included MS-DOS 7.1 command line, and which can also run Windows 3.11. I've seen various disjointed posts online that suggest this is ...
30
votes
7answers
10k views

Did the computer mouse always output relative x/y and not absolute?

I am experimenting with a graphics pen and tablet and it got me thinking about the difference between it and my mouse. One huge difference is that the tablet's working area covers the whole screen, ...
3
votes
1answer
279 views

Is there a git build for Windows 9x

Obviously, given age, doesn't have to be as secure and fancy and the modern builds, but is there there a git build for Windows 9x, just like there is for Windows XP? Also wondering whether there is a ...
-4
votes
1answer
152 views

Why did Western Digital name their drives “Caviar”? [closed]

I'm asking in Retrocomputing because the Caviar line of HDDs was released in the most recent era of retrocomputing. Does anyone know why they named the line "Caviar"? Why do they associate Sturgeons ...
5
votes
0answers
130 views

PET LOAD command and the < key

I remember reading (probably in some issue of the newsletter of the PET Benelux Exchange (PBE)) about a strange effect during tape loading of a PET program. Back in the day, I tried it and it worked. ...
11
votes
2answers
698 views

Limitations for Color Usage in NTSC

In a well known letter to Philip Timmermann, Robert Yannes describes C64 color generation hardware as capable of producing any color (the palette was fixed, of course, but chosen semi-arbitrarily and ...
7
votes
4answers
593 views

Self-modifying code in commercial games for the (S)NES, Gameboy, Genesis/MD, PC Engine, Atari, etc

I'm curious if there are any extant examples of commercial games for classic consoles (let's say, pre-32-bit era here) which make uses of self-modifying code. As far as I know, all the systems I've ...
20
votes
8answers
3k views
+50

Do the holes in Jacquard loom punched cards represent input data or program code?

I think they represent data because I feel it is a mechanical machine which is fully configured and the holes decide only that the thread related to each hole must be moved or not. Thus the holes ...
5
votes
1answer
141 views

Were Artworx and Dynacomp the same?

Back in the day my copies of Creative Computing always had a two-page add from Dynacomp somewhere in it, like this one. Tracking down some of the programs, it appears they are also almost all also ...
2
votes
3answers
152 views

Semis and spaces in MS-alike BASIC PRINT commands

With the exception of DEF FN and the handful of direct-mode commands (CONT, LIST, etc), my interpreter is running most programs, but layout remains an issue. Here are three lines from the BASIC ...
4
votes
1answer
227 views

Can't boot FAT32 larger than 2GB, unlike Fat16

Why can my PC not boot Fat larger than 2GB (Fat32) in legacy mode, but FAT16 and NTFS work fine? It just gives me a non-system disk error, while booting the same (Dos boot disk) files under Fat16 ...
16
votes
4answers
5k views

Why are old computers so vulnerable to temperature changes and moisture?

Interesting discussion by someone thinking of procuring a PDP-11/34, though having difficulty finding suitable space for it: https://www.reddit.com/r/retrobattlestations/comments/dztvci/...
1
vote
3answers
179 views

How can I clean the RF-Out jack of the SNES

I have got a Snes which is in pretty good shape. My problem is that the RF jack is very dirty and corroted. I haven't tried cleaning it because I think I could accidentally break it. (The jack is ...
8
votes
1answer
704 views

Did any significant programs or environments take advantage of the Rexx which came with PCDOS 7 (aka PCDOS 2000)?

Being an Amiga fan, I have a fondness for the Rexx language. On that platform, almost every significant program supported ARexx, allowing a high degree of interoperability and customability. So when ...
1
vote
1answer
181 views

What early computers were only able to print numbers?

According to this paper (translation), one of the early soviet machines, M-1, was only able to print decimal, and not alphabetical numbers. Which other early electronic stored program computers (i.e. ...
3
votes
4answers
366 views

What is the first (say early) use of switches (mechanical or electromechanical) for sake of processing (like automatic motor control)simple data?

Switches are intended for just turning ON or OFF the power supply by either closing or opening the circuit. I often wonder how does mankind got idea to use these switch for sake of processing (simple ...
3
votes
1answer
126 views

SID to WAV converter that exports per channel separately

For a C64 SID project of mine (https://soundcloud.com/c64er) I was using an converter almost 10 years ago, but it is missing now with its name... I researched many sites, but no lucky. Is there any ...
5
votes
1answer
379 views

SCSI to USB interface

I just took the hard drive out of my old beige Mac G4 (don’t know if it still works). I haven’t used this computer for the longest time and I’m interested to see what is on the drive. Is there an ...
2
votes
2answers
183 views

INPUT with comma vs. semi

I certainly don't recall this at the time, but I'll ask to be sure. According to the GW-BASIC documentation, a semicolon between the INPUT prompt and the variable suppresses the question-mark prompt. ...
23
votes
1answer
6k views

What was the first operating system called DOS?

MS-DOS a.k.a. PC-DOS nee QDOS, was commonly just referred to as DOS. But 'disk operating system' is a very obvious acronym; there must have been previous operating systems so called. What was the ...
17
votes
3answers
3k views

Was Locomotive BASIC significantly better than Sinclair BASIC?

The Amstrad CPC range of Z80 machines shipped with a ROM BASIC, designed and implemented by Locomotive Software. The most well known competitor was the Sinclair ZX Spectrum, also a Z80 machine, with ...
15
votes
2answers
2k views

Why are branches relative in many 8-bit CPUs?

I was looking over an old article on the 6809 and was perusing the opcodes and noticed that the branch instructions came in two flavors, long and short. That sparked a memory about one of the 6502-...
8
votes
4answers
574 views

MS BASIC, access a DIMed variable with no index?

I'm working my way through my retrobasic interpreter, feeding it an expanding diet of 101 BASIC Games. Here's an odd one... 40 DIM F(6,6),H(6,6),A(4),B(4),C(6),L(3) ... 90 A=INT(6*RND(1)+1) This ...
3
votes
2answers
154 views

What is the name/type of the Apple IIc case screws?

My Apple IIc is what appears to be the first US model: A2S4000 with version 255 ROMs. The upper half of the case is held to the base with six Phillips drive button-head 2 cm screws with a very wide ...
3
votes
0answers
72 views

How do I clean/refurbish an Apple IIc Keyboard?

My Apple IIc is what appears to be the first US model: A2S4000 with version 255 ROMs. The keyboard PCB is marked 820 0108 03 ©1983, and the keyswitches are the "cross" type as seen below, without any ...
13
votes
3answers
1k views

Memory models for assembly libraries for Turbo C

Turbo C follows the Intel Memory Model where in Tiny, Small and Compact models calling a function is near but in Medium, Large and Huge models calling a function uses far calls. If I want to develop ...
5
votes
1answer
208 views

Monochrome CRT Repair - Horizontal offset

My CRT all of a sudden is shifted to the right. I cannot adjust it via the adjustment potentiometers, nothing changes when these are turned. If I increase the brightness, the whole screen turns green (...
71
votes
6answers
11k views

Exactly what color was the text on monochrome terminals with green-on-black and amber-on-black screens?

I am wondering what were the color shades and brightness of the text appearing on classic monochrome terminals? If I were to recreate approximately the green-text-on-black-screen or amber-text-on-...
3
votes
2answers
386 views

What was stored in memory that was “unavailable to BASIC”?

On home / personal computers (such as before 1984), a machine might be described as having 24k RAM, but only 18k of that available to BASIC. If the machine had BASIC and the OS (or BIOS) stored in ROM,...
1
vote
1answer
157 views

ZX Spectrum: What is the “T” state value, with reference to sound?

I have that awesome book - Zx Spectrum ROM Disassembled (correct the title if I got it wrong), where the author wrote about the audio code in the ROM and referring to "T" state, "... T200... T5000, ...
8
votes
2answers
1k views

Did any 360-compatible machine implement registers in core?

In the early days of transistors, when they cost on the order of a dollar each, it was possible to implement CPU registers with magnetic cores (the technology used for main memory at the time) instead ...
4
votes
2answers
187 views

How did IBM's “Mag Card” drive and magnetic media work?

In the 1970's IBM popularized an early word processing solution using their popular Selectric typewriter line and something called "Mag Card". This video demonstrates the system in operation. The ...
25
votes
5answers
4k views

What type of interpreter were most 8-bit BASIC implementations?

I’m a big fan of early/mid 1980s personal computers like the Amstrad CPC, Commodore 64 and the Sinclair Spectrum. One thing these computers all had was a version of BASIC. Well known ones being MS-...
9
votes
2answers
587 views

How can I read a 5-1/4 drive on 1996-2007 equipment?

In my organization's archive I just found some 5-1/4" floppies, presumably IBM PC 320/360k. They contain information that we have on paper, but I'd really like to have on electronic media, not least ...
2
votes
1answer
117 views

What was the first company to sell an IBM compatible punchcard reader?

Punchcards were the primary way to get information into computers up through the sixties. The familiar eighty column format was designed by IBM, and was a factor in the later de facto standard eighty ...
2
votes
1answer
77 views

What are the differences between the various HxC Floppy Emulator hardware options when used with an Apple II?

I have an Apple IIc for which I would like an FDD emulator and I am considering buying an HxC Floppy Emulator to use with it. The Slim model does work with the Apple II, as demonstrated in this video. ...
34
votes
10answers
13k views

Were there ever 12-, 24-, 48-, etc bit processors?

After seeing this question, I was struck with an intense curiosity to know: Were there ever processors with word sizes that aren't powers of two, specifically after the 8-bit byte became the industry ...
6
votes
4answers
410 views

Were there any games/software that used a resolution or resolution-mode higher than what was advertised available on the machine?

Were there any games/software that used a resolution or resolution-mode higher than what was advertised available on the machine ? On home / personal computers between anytime - 1984 . Without ...
8
votes
2answers
2k views

What should be the waveform for ZX Spectrum tapes?

I am digitizing about 40 tapes with programs for the ZX Spectrum. I am somewhat puzzled by the waveform after digitization. The signal of most cassettes is meander-shaped. One of the cassettes can ...
1
vote
3answers
292 views

Were there any games/software that used memory beyond what was advertised available to BASIC on the machine?

Were there any games/software that used memory beyond what was advertised as available to BASIC on the machine ? On home / personal computers any time before 1984 . Without needing to plug in any ...
23
votes
8answers
5k views

What other tricks were there to get more data onto floppy disks?

I remember using a utility back in MS Dos 3.3 days, called maxi-disk, that somehow magically managed to get 420K on a 360K 5 1/4" disks. I assume it managed it by destroying some redundancy like a ...
12
votes
1answer
458 views

What is the “Data Language” paper referenced in RFC 309?

RFC 309 is an announcement of the 1972 Data and File Transfer Workshop announcement. The suggested reading section has 12 entries, 11 of which are RFCs and the last of which is: 8. Data ...
5
votes
1answer
281 views

What is the C64 disk drive “Jiffy” protocol?

There seems to be something called the "Jiffy protocol" used for some fast load systems. I know of the JiffyDOS product, which seems to require replacing ROMs in both the C64 and the drive, but it ...
6
votes
2answers
201 views

Are there any open-source C64 DOS wedges and fast loaders?

The ever-so-popular EPYX Fast Load cartridge for the Commodore 64 included a DOS wedge (adding commands such as $ to list the files on a disk, /filename to load a file and @ to show the disk error ...

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