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votes
2answers
509 views

What file formats were used for binary executable files on later Sinclair ZX Spectrums?

The last official version of the Sinclair ZX Spectrum was the +3, released after the company was owned by Amstrad. It included a 3-inch floppy disk drive as used on other Amstrad computers. But even ...
5
votes
1answer
273 views

Where did the lookup table in Entombed come from?

Entombed is an Atari 2600 game where you move through an infinite vertically-scrolling maze and try not to die. This maze is procedurally generated, with two bits from a PRNG (underlined) added each ...
13
votes
3answers
1k views

PC/AT two DMA controllers - what is the purpose of cascade channel and how did it work?

Why did the design need to reserve one channel for cascade, how did it work and what exactly was going on there?
5
votes
2answers
276 views

ES688 AudioDrive 4-bit proprietary codec: Any way to decode?

I have files, which I recorded back in 90s with ESS ES688 AudioDrive card, 4-bit voice optimized codec. Nowadays I do not possess the card any more and proprietary codec is no longer supported or I ...
1
vote
3answers
200 views

How do I interpret these instructions for decompressing game data? [closed]

I'm trying to write a tool for the 1994 SNES game Super Metroid that creates "out of bound" maps for each the game's rooms. To do so, first I need to extract the tile-by-tile data of each room. For ...
8
votes
1answer
176 views

How Amiga A590 autoboot ROM and bootable floppy disk works?

Commodore A590 was a peripheral hard drive and memory expansion unit for Amiga 500/500+ computers. It provides SCSI and XT-harddrive controller and 2MB Fast Ram. Here is the Big Book of Amiga Hardware ...
31
votes
11answers
7k views

What “unusual” syntax assembly languages are/were there?

This question may have the apparent form of a question soliciting a "list" answer, but I'm expecting the list to be very short, so please bear with me. What "unusual" syntax assembly languages are/...
3
votes
0answers
188 views

What monitor could render APL2 characters in 1985?

BACKGROUND: In 1985, I took an evening class in APL at the local IBM as part of a high school Explorer Post (which was really cool, these guys giving up their time to teach us programming). Other ...
3
votes
1answer
367 views

What 1970's terminal was black on white and had an orange keyboard?

In high school, I programmed on a terminal that was retro THEN, and I need help remembering make and model. White screen, black text (seemed very unusual to me), no lowercase, 24x80, and I have this ...
6
votes
2answers
445 views

What 6800 assembler to use?

Does anyone know of a good, modern Motorola 6800 assembler? I've used dasm, which I quite like (and it's even actively developed), but it doesn't actually support 6800. It supports 6803, which is ...
11
votes
1answer
280 views

Inverting the carry flag on an M6800

Are there any tricks that can be used to invert the carry flag on the 6800, in as few bytes as possible? This is the shortest subroutine I've come up with, which is straight forward: INVC: BCS ...
54
votes
1answer
3k views

How do I extract the program from the Radiohead “Nude” tribute by James Houston?

One of my favorite videos ever is a tribute to Radiohead "Nude" by James Houston. I have never seen the program in the video available to download, so I've just made an attempt to extract it myself. ...
4
votes
0answers
149 views

How can I connect a PIA or VIA chip to the Apple IIc?

I have an early Apple IIc, model A2S4000 with the 342-0272 motherboard and ROM 255. (I am considering upgrading the ROM, perhaps with a switch that would let me switch between different ROM versions.) ...
7
votes
2answers
299 views

How to print from a IIgs to a modern printer?

How can I get a IIgs to print to a modern printer? The IIgs is running Appleworks GS under System 6.0.3 with 2 MB of RAM and a hard disk. Ethernet is an option as I have a LocalTalk to Ethernet ...
8
votes
1answer
302 views

Which computers used the Intel 82786 graphics chips, and what sort of commercial success did that chip attain?

In the late 1980's, Intel offered the 82768 graphics chip, with specific support for windowed environments. I remember it being covered in Byte magazine, but don't remember seeing any applications of ...
13
votes
5answers
1k views

How are blocks stacked on a floppy or older HD

I tried to understand how to read a floppy image format (.sdk). The format is based on CP/M 2.2 filesystem. I've lost track, and I think it's my third attempt. Now I am looking more into what these ...
9
votes
1answer
463 views

Did the Commodore 128's Z80 CPU also have full access to the machine's custom hardware?

The C128 was a C64 with an extra CPU as well as extra memory. But the second CPU was a Zilog Z80 while the primary was the usual Commodore CPU, a MOS 6502. The Z80 was there so that CP/M software ...
5
votes
1answer
223 views

Are there games for the C128 that run (mainly) on the Z80 rather than the 6502?

The Commodore 128 was a version of the Commodore 64 that also had a Z80 CPU along with its "native" 6502 CPU so the system could run CP/M as well as C64 software. (As well as more RAM and other ...
8
votes
5answers
416 views

When connecting to the Internet via Dial-Up, were computers directly accessible via their allocated IP address?

From carrying out some brief research, it appears that as is the case today, when using Dial-Up to access the Internet customers were often allocated a dynamic IP address by their ISP. Typically, when ...
6
votes
2answers
549 views

Why does the .z80 emulator-snapshot format have separate fields for the 8-bit refresh register and bit 7 of R?

I've been looking at the .z80 file format for Sinclair ZX Spectrum games. Most docs discussing the format include pretty much this wording: Offset Length Description -----------------------...
9
votes
3answers
3k views

What are these 3COM connectors for?

I came across this set of connectors. All are labelled 3COM and go from some type of plug that I can't identify to an ethernet end. Two of them have female RJ15 sockets, one has a male RJ15 plug. ...
4
votes
3answers
387 views

Is there any use for PC Magazine issues from the 1990s?

I have what seems to be at least several year's worth of PC Magazine from the 1990s. Before I toss these in recycling I was wondering if someone, somewhere, would find any use for these. I doubt a ...
1
vote
3answers
154 views

How were customers typically charged when purchasing Dial-Up Internet services from an ISP? [closed]

This is a follow-up from my previous question - When connecting to the Internet via Dial-Up, why did ISPs require a username/password to authenticate the session?. In the above question, we ...
2
votes
1answer
63 views

Where can I find original Apple DOS 3.3 System Master diskette images?

The original Apple DOS 3.3 was released on 1980-07-25, and there seem to have been at least two more updates after that that did not bump the version number: Two more versions of Apple DOS, both ...
8
votes
1answer
555 views

Why did the Commodore PET 2001 take so long to ship?

In 1976 Commodore as a company had been running for more than twenty years and had extensive experience with designining and selling consumer electronics products: they were one of the top-selling ...
2
votes
1answer
388 views

Looking for a strange DOS database gui that ran on 286+

I have recently been getting into older apps from when I was a kid; one of these was this strange DOS shipping(?) database gui that ran on at least a 286, but looked like Windows 3.1; however when you ...
2
votes
3answers
195 views

C/C++ UI library similar to Visual Basic for DOS

I'm looking for a UI library that offers a similar "experience" to that provided by Microsoft's infamous, Visual Basic for DOS RAD environment. I mean, it's such a compelling environment, and there's ...
23
votes
9answers
6k views

Why did 8-bit computers choose BASIC dialects as “de facto” command-line interface, instead of contemporary Shell/Lisp dialects?

While all three clans of languages predated 8-bit computers, they shares features like 1) imperative programming, 2) English-alike keywords, 3) Prompt-Command-Parameters pattern interface. Why was ...
15
votes
3answers
1k views

For how long can you safely stop the clock on an NMOS 6502?

As with most NMOS processors, the NMOS versions of the 6502 (and even earlier CMOS versions) do not have a static core. Thus, if you run the clock too slowly or stop the clock for too long while doing ...
6
votes
2answers
319 views

Are there standalone emulators of Applesoft Basic?

My only retrocomputing desire is to program in Applesoft Basic and relive the Apple II days from the 1980's. Playing games is of no particular interest to me. I just want to use a keyboard, not a ...
5
votes
1answer
169 views

Trying to use IBM model F (5 pin DIN) with modern Windows PC

I have a vintage IBM Model F which I just bought from eBay, that I am trying to connect to my new Windows Pc. I ordered a DIN to Ps/2 converter from Newegg, because I my pc has a combined ps/2 port, ...
9
votes
0answers
139 views

Why did IBM develop 5250 block mode terminals when 3270 already existed?

IBM introduced the 3270 family of block mode terminals in 1971, for use with IBM mainframes (System/370 and successors). Then, in 1977, IBM introduced the 5250 family of block mode terminals for use ...
24
votes
3answers
4k views

When connecting to the Internet via Dial-Up, why did ISPs require a username/password to authenticate the session?

It's been many years now, but when I used to connect to the Internet via Dial-Up back in the day I noticed at the time that as well as entering the phone number for my Dial-Up provider, a username/...
8
votes
1answer
785 views

How to find out what OS version & CPU type used in Windows CE

How to find out what OS version & CPU type used in Windows CE? Without disassembling the device, and compiling software?
5
votes
2answers
380 views

Data length module of 3.2^n confusion in IBM system/360 architecture

I'm currently reading about the IBM system/360 architecture and there's a part that has me very confused: The decision on basic format (which affected character size, word size, instruction field, ...
10
votes
0answers
258 views

Why would installing Windows 9x on a Sager NP8200 or Wedge 466/DX2 laptop brick the system?

In the setup.txt file on the Windows 95 and 98 CDs (located in the \WIN95 [Windows 95] / \win98 [Windows 98] folder), which contains important information on setting up Windows and solving or working ...
10
votes
1answer
742 views

Why did the C64 use a separate “CAN” +5 V power supply for some chips?

The Commodore 64 had two separate +5 V power supplies: one supplied by the external PSU brick and a second one generated on-board from the 9 VAC via a 7805 regulator. This second +5 V power supply was ...
14
votes
1answer
9k views

Is this a mini computer, a novelty monitor or something else? [closed]

I saw this in the background of a video and I'm wondering what kind of device this is. It looks like a small pink CRT monitor with some keyboard-like buttons and was playing an animation.
1
vote
1answer
115 views

How can I fix this clacking sound made by the Game Boy speaker?

I have a Game Boy, and whenever it tries to play sound, the sound is very quiet but there's a loud clacking sound. Here is a sample. In this case, it is Tetris Attack playing: https://soundcloud.com/...
6
votes
2answers
180 views

Why does _Beneath Apple DOS_ show FM encoding rather than GCR?

From the beginning in 1978 the Apple II floppy disk system used GCR encoding to convert data bytes to sequences of binary values to be written to the diskette: first 4-and-4 encoding (never released), ...
23
votes
3answers
4k views

Could you manually eject a floppy quick enough to prevent data loss?

I have the vague recollection of "Panic Ejecting" floppy disks by lifting the latch on the drive after immediately regretting a command I had typed. At the time, I was young, impulsive, and blessed ...
8
votes
0answers
108 views

What is the protocol for bootstrapping a Game Boy Advance over a link cable?

One of my favorite features of the Game Boy Advance growing up was the ability for some games to be played multiplayer with just one cartridge - the first player would have the cartridge and all the ...
53
votes
4answers
12k views

Why were most PC's and electronics beige back in the day?

Back in the day (especially during the 70's and 80's) it seems that most computers and electronics were colored 'beige'. It seems it would be easy to use different colors, so why didn't they? Some ...
5
votes
2answers
141 views

Mismatched floppy disk/drive reading and writing, what should one keep in mind?

Mismatched disk/drive refers to, for example, reading/writing a 720K disk with a 1.44M drive. Don't forget LS-120 and LS-240 SuperDisk drives, they can use standard floppies too. What can and can't ...
1
vote
4answers
462 views

Is the ZX Spectrum multithread capable? [closed]

I know the spectrum had the IM2 mode, but can I start multiple threads running simultaneously? In example: can I play a song, while transfering large amounts of data, like in large ldi code blocks? ...
15
votes
2answers
1k views

How does Windows 9x determine which disk drivers correspond to which BIOS disks/DOS drive letters?

Windows 9x can employ two kinds of disk drivers: native protected-mode drivers and compatibility-mode DOS drivers, and the former are used in preference to the latter whenever possible. When Windows ...
20
votes
3answers
1k views

Does the “Amiga Client for Novell NetWare” exist?

On page 139 of Brian Bagnall's book "Commodore: The Final Years", there is the statement that at CeBIT Hannover in March 1989, Commodore announced (amongst other things) "Novell Netware for Amiga". I ...
0
votes
4answers
280 views

What is the earliest implementation of the stack data structure in C? [closed]

I am trying to find the source code for the earliest implementation of the stack data structure in C, but I can't find anything. I am particularly interested in knowing if the member variables of the ...
-1
votes
1answer
97 views

Casio CW16 Typewritter [closed]

I am in need to refil my typewriter with more ink(this model uses ink ribbons), but in the place where I live they dont sell those ink ribbons anymore, I am considering to buy some cheap nylon ribbons,...
42
votes
6answers
7k views

How did old games from 8-bit era game consoles store music?

Some time ago I found that the audio of a game called Ninja Gaiden 1 (NES) is around 1 hour. This is excluding the sound effects like jump and hit e.t.c. Then I found that the entire game size is ...

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