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12
votes
2answers
1k views

Was Apple DOS 3.3 created because of the Apple III?

I recently read a document which discussed how the Apple III would implement the Apple II emulation mode. On page 20, it goes on about difficulties involved with how the Apple III would have ...
20
votes
3answers
1k views

PDP-11 instruction set inconsistencies

The wiki page PDP-11 architecture has a cryptic paragraph with no references or examples: Inconsistent instructions Over the life of the PDP-11, subtle differences arose in the implementation of ...
6
votes
4answers
1k views

Reading the program on an EPROM chip

Is it possible to build a breadboard device to simply view the code burned into a 28 pin or 40 pin DIP chip? I do not intend to do any erasing/programming on the chips, just wanted to view what is on ...
4
votes
1answer
462 views

What are the major differences between the ColecoVision and the SG-1000?

According to Wikipedia, the ColecoVision and the Sega SG-1000 were almost identical. I'm curious about that "almost" part. For example, they both used the same video generator (TMS9918/28). They ...
12
votes
7answers
3k views

Were there any “off the shelf” graphics chips that supported 2D sprites in the 70's and 80's?

I'm looking for "off the shelf" graphic IC's that supported hardware sprites. By "off the shelf" I mean chips that were designed to be used in various machines and not designed specifically for one ...
26
votes
6answers
3k views

Core Memory Stability

How reliable was the ferrite ring core memory system? When the power went off, did all the magnetic positions of the iron rings in the program wire grid remain exactly as they were?
8
votes
4answers
879 views

When did the tower form factor appear and when did it become popular?

Essentially, my question is there in the title. Tower cases are commonplace these days, and probably are the "default" form factor for personal computers (or at least were, before they were surpassed ...
3
votes
1answer
332 views

Using audio tape recorders on non-personal computers?

A Soviet manual (1978) for an interactive integrated development system named ПУЛЬТ (translated as "console" or "[remote] control panel") developed for the BESM-6 mainframe contains a cryptic note: ...
26
votes
10answers
6k views

Graphics chips in 1980

Suppose you were trying to build a computer with a color graphics display in 1980, you have limited engineering resources and time to market is critical, so you want to get as many of the parts off ...
12
votes
1answer
444 views

Sprites not rendering correctly before $2000

I am currently testing out some stuff in assembly with C64Studio and Vice and I noticed something with odd sprites. My code starts at $1000 and my sprites at $2000 but when I try to lower the first ...
34
votes
3answers
5k views

What was the point of Apple Pascal having its own file system?

Apple's UCSD Pascal for the Apple II used its own file system rather than the existing DOS 3.3 of the day. I'm not sure if it overlapped SOS at all, but regardless of timelines it seems that the ...
12
votes
2answers
2k views

Where did Fast InvSqrt() come from?

The fast inverse square root algorithm is probably best known for its use in Quake III Arena, the source code of which was released to the public a few years after its release. However, the algorithm ...
16
votes
4answers
2k views

How to use BASIC after “LOAD ”$",8 on the C64

After loading a file list from a floppy disk it is hard to program in BASIC because the file list is interpreted as BASIC lines. For example there can be 20 lines with the number 1, because 20 files ...
12
votes
4answers
783 views

Old school backup systems: what are they?

So being a sysadmin for several years, I learned that "Jesus saves, but God makes tape backups," several times over. Watching Season 2 of Halt and Catch Fire, there is some data loss. Being that ...
6
votes
2answers
621 views

How does the MSX2 game “pointless fighter” obtain a graphic above the average?

The Homebrew game "pointless fighter" (https://youtu.be/PReg7pPcbIY) has graphics and animations substantially better than most of the MSX2 games. Is there a technical breakthrough which permits such ...
13
votes
3answers
1k views

Pattern matching, which language first had it

Which programming language was the first to use pattern match? The oldest ones I know are: Prolog 1972 ML 1973 Are there languages older that have pattern matching? Edit: By pattern matching I ...
5
votes
1answer
526 views

Why did Nintendo change their copyright title between Donkey Kong Set 1 and 2?

Early American Donkey Kong arcade machines used US Set 1 and the game title had "1981 Nintendo" as the copyright. Later US boards used Set 2 and Nintendo changed the copyright title to "1981 Nintendo ...
9
votes
4answers
7k views

How to renew and re-ink old printer ribbons?

What is the proper way to restore and re-ink old typewriter, calculator, dot matrix printer, and mainframe lineprinter ribbons? Usually fabric ribbons or open-cell foam sponge rollers were used to ...
5
votes
2answers
373 views

Checklist for powering up an Apple IIgs?

I've just been given an Apple IIgs that hasn't been turned on since 1999. What's a reasonable set of checks to go through to make sure I don't toast the thing the first time I plug it in? The machine ...
10
votes
3answers
1k views

Why should 2 CPUs ever share the same bus?

The complexity of the Sega Saturn's technically impressive hardware played a large factor in its downfall. It seems to me that one of the largest things that was difficult to work with was that the 2 ...
3
votes
1answer
253 views

Which material was used for the 6502/6510/8500 MOSFETs?

I know that in the 80s, there was a shift from aluminum gate material to polycrystalline silicon. I wonder because the 6502 was released in 1975 and there were a lot of different implementations and ...
2
votes
2answers
589 views

What chemicals or materials were used to create the logic for logic gates?

Back in school I took a couple electrical engineering classes and we did a lot of Boolean math using logic gates (AND, OR, XOR, NAND, etc), but never talked about how exactly the logic in a single ...
9
votes
2answers
591 views

Can we get a complete timeline on the IRIS Operating System for Data General Novas?

This OS was implemented on DG minis in about 1970 by Educational Data Systems. Dan Paymar, one of the EDS cofounders, hired me to help him complete a one-user diskless Basic Interpreter in Summer ...
9
votes
4answers
954 views

What's a safe and easy way to desolder the CPU from C64?

I have probably broken my CPU by connecting 5 V from Arduino (500 mA) to the SENSE Pin of the Casette Port, So now I wonder what would be the safest way to desolder the processor? I have a cheap ...
9
votes
2answers
509 views

How to obtain CPU and other hardware specs for emulator development

In order to write emulators for older systems, one has to know the "inner workings" of the original hardware and understand what makes it "tick". I've noticed that with some systems, proprietary ...
73
votes
14answers
17k views

Did any 8-bit computer system / OS have concepts for concurrency and multitasking like we know from today?

So, today all major OS support multitasking and concurrency in languages like for instance threading. The Amiga seems to be the first home computer which has advanced concepts in this area. But had ...
8
votes
3answers
1k views

How to develop software for the Commodore 64 with VICE?

I see a very large fan-base and hear a lot (especially here on retrocomputing) about how great the Commodore 64 was. Growing up in the Windows 95/98 era, I seemed to have missed a great era for ...
2
votes
2answers
704 views

Educational DOS game involving teddy bears

I remember when I was very young (mid-to-late 90s) playing a probably educational DOS game that was like a whole bunch of minigames. At least one of the minigames (perhaps all of them) was teddy-bear-...
10
votes
8answers
1k views

Emulators running on 8-bit personal computers

Were there emulators running on 8-bit computers (preferably "mainstream" personal ones), available to general public (as opposed to in-house developers only)? I am mostly after emulators running fully ...
13
votes
1answer
956 views

Early Apple assemblers, getting hold of them

The apple ][ history site https://apple2history.org/history/ah17/#05 has a section on assemblers with these interesting snippets: TED/ASM: Developed at Apple and smuggled out the doors around May ...
6
votes
1answer
1k views

Submarine diver game where you had to collect fish and other things for your aquarium

I've been searching for a game that I used to play a ton when I was a kid on the Windows 95/98, but I can't find it for the life of me! From what I remember, you were a deep-sea diver that collected ...
8
votes
4answers
851 views

A game where you program a robot to fulfill missions

I'm looking for a game. Unfortunately there're only few things I remember: You had a robot. There was no way to steer it manually, so to solve a room, every step to do had to be programmed in advance ...
1
vote
0answers
148 views

Historical cost of semiconductor fab [closed]

How much did a state-of-the-art semiconductor foundry cost in or around 1980? Ideally I'd like to get data on how it changed over time from the seventies to present day, but even a single data point ...
1
vote
1answer
104 views

PCB Black Spot: Leakage?

Photo album, sorry for the hassle Quick question: Ceramic disk capacitor has leaked? Or a dodgy soldering technique? This is a quite old calculator, it's an arbitrary model nowhere to be found. Any ...
13
votes
1answer
1k views

Number of transistors in the C64

How many transistors are there approximately in the C64 if we consider every chip on it? I think that it is something around 50.000 but I'm not sure.
9
votes
1answer
846 views

Was there a 'git' in the 1990s?

I seem to remember using a source code control system back in the early- to mid-1990s called git. Am I nuts? I used to work at IBM way back then. We didn't use it for a big project, but I distinctly ...
8
votes
3answers
574 views

Did blowing into an N64 cartridge really affect whether or not the game would run?

I remember when playing on the N64 if the game didn't start running when I turned on the N64, I would remove the cartridge, blow into the cartridge where the pins were located, then slam the cartridge ...
28
votes
9answers
10k views

Should 486s have a heatsink?

I'm building a 486 computer. I plan on using a 100 MHz 486-DX4 that I have which I believe is about as fast as 486's went. The motherboard I will use (Socket 3) appears to support putting a heatsink ...
14
votes
4answers
2k views

How powerful was Knuth’s computer?

The Art of Computer Programming, volumes 1–3, was written in the late 1960s, with vol 3 finalized in Sept 1972 after a delay of “almost 3 years” because of rapid development of the subject matter. I ...
6
votes
1answer
394 views

What algorithm does Windows 98 use to decide whether to show or hide menus?

A comment on User Experience reminded me that Windows 98 keeps the All Programs submenus open when the mouse isn't on the menus, but if the mouse strays too far from the menus for long enough they all ...
20
votes
2answers
5k views

What computer was used in Weird Science?

In the 1985 movie Weird Science, two teenage boys use a computer to create a girlfriend (Kelly Le Brock). I've seen that movie 20 times or so but I still couldn't make out what computer they use. I ...
43
votes
3answers
6k views

What is between the sectors of floppy disks?

I've found this page which has an informative description of how sectors were encoded on floppy disks: http://nerdlypleasures.blogspot.com.au/2015/11/ibm-pc-floppy-disks-deeper-look-at-disk.html Do ...
4
votes
1answer
531 views

Potentiometer rebuild - inexpensive damping grease?

I successfully took apart an Atari 2600 paddle controller, then cleaned and appropriately lubricated the contacts. However, the volume knob does not have the same smoothness as it does on the other ...
11
votes
1answer
1k views

Why would a CD-ROM in an MS-DOS 6.22 system not allow file access?

I have an OS/2 Warp CD that I am wanting to use as the installation media on an IBM PC 350 Pentium system. I have already installed MS-DOS 6.22 and the IBMIDECD.SYS driver for the CD-ROM drive on the ...
16
votes
2answers
1k views

Creating a new locale.library language support for AmigaOS

Looking through the LO (localisation) disk for Workbench 3.1, I see that the language files are binary. I'd like to create a Gaeilge (Irish) localisation file. How is this done on Amiga? Update: ...
28
votes
1answer
3k views

What is the relative code density of 8-bit microprocessors?

When RAM is at a premium, as it was in the old days, a greater code density of an instruction set can be a substantial advantage. (Click saver: Code density refers loosely to how many microprocessor ...
10
votes
1answer
768 views

Whatever happened to the janus protocol

Back in the day, when I was running a bbs, blinkyterm was just coming out with the new janus bidirectional file transfer protocol which was hoped to displace zmodem et al for bbs to bbs file transfer (...
6
votes
2answers
179 views

Recover files from Dell PP04L Hard Drive

I have my mom's old Dell Inspiron 2650 model PP04L. She is passed away now but I'd like to salvage some of the old pictures and things she had on there. Is there a way to buy an enclosure and mount ...
11
votes
1answer
523 views

What does bold reverse video look like on a VT100/VT102?

My understanding is that bold text on a VT100/VT102 is more intense than ordinary text; I might say that normal text is 80% grey and bold text is 100% grey=pure white, for the sake of illustration. ...
12
votes
3answers
657 views

What interface did Video Backup System use?

I remember the Video Backup System for Amiga advertized in Polish computer magazines of late 90s, "store hundreds of diskettes on a single VHS tape!" I seriously considered buying it (and a VCR since ...

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