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5
votes
2answers
669 views

Are floppy disks used for MS-DOS setup still needed after you install the operating system?

I currently only have 11 disks available. One of the disks is a reserve, so I will not use it unless I have to. That brings us down to 10 disks. Disk 0 - Blank, I will use this for the installation ...
8
votes
3answers
633 views

Connecting an Atari 130XE to SM124 monitor

I've got an Atari 130XE 8bit computer that has Composite Video Output. Also, I've got an Atari SM124 monitor designed for the Atari ST 16-bit line of computers. If you look at an Atari 130XE packing ...
18
votes
7answers
2k views

Was Amiga the last of the home retrocomputers sold?

The Commodore-Amiga was offered for sale to home users from 1985 (original A1000 in North America) until 1996, when Escom stopped selling the A1200. By 1996, Apple was selling PowerPC-based Macs for ...
7
votes
3answers
140 views

Format of “Pound” domains in RFC 821

This is a bit of an archaeological question, but RFC 821, page 31, paragraph 3 describes a syntax for mailbox addresses that is of the form local_path@#123, where the pound and the following number is ...
7
votes
2answers
285 views

Is it safe to provide 5V to CMOS RAM from PSU instead of CR2032 battery?

I have a motherboard which stores BIOS settings in a DS12887 chip with internal battery. The battery is long dead, and the pin of chip's socket is not connected to any power supply so the chip doesn't ...
11
votes
2answers
482 views

What's the meaning of __saveds in Amiga C code?

What's the meaning of __saveds in Amiga C code? It's applied to function prototypes, and is required for functions that are to be called by assembler code, if I understand correctly.
9
votes
3answers
575 views

Can the BBC Master 128 work fine with no battery?

The BBC Master 128 has a CMOS NVRAM and battery system for storing configuration information. I assume that a dead or removed battery just leads to the NVRAM reverting to defaults or other non-harmful ...
9
votes
3answers
3k views

What “Write your own RPG/Adventure game” books were available for 8-bit computers? [closed]

During the 70s and 80s there were a number of books about how to write your own games for 8-bit computers, usually in BASIC. Three examples of these books are How to Create Adventure Games by ...
18
votes
10answers
5k views

640x480 color display in 1980

I'm working on an alternate history story in which the protagonists, Silicon Valley computer entrepreneurs, are trying to release a graphical workstation in 1980, with the capability of displaying ...
11
votes
3answers
414 views

What kinds of expansion ROMs and cartridges are available for the BBC Micro?

The BBC Master 128 has 3 empty expansion ROM sockets and 2 cartridge slots, which seems like a lot of potential. I have already discovered that it is common to add an expansion ROM to support a filing ...
8
votes
1answer
641 views

What is the history of data compression tools on personal computers?

On UNIX, the progression of the most widespread data compression programs was as follows: (AFAIR: Pre System V) compact (suffix .C), dynamic Huffman coding (AFAIR: introduced in System V) pack (...
7
votes
1answer
383 views

Were 1541s upgraded with more RAM?

Since the Commodore 64 was often used with one or more 1541 drive, and these had CPUs which could run user code, it makes sense to me that these would have been expanded in the day, to have roomier ...
5
votes
1answer
296 views

What are all the known file extensions for Atari 8-bit disk/tape/cartridge images?

I have a few collections of Atari 8-bit images that I've downloaded over the years, but only cherry picked into them. I'm at the point that I'd like to clean things up a bit and get rid of files that ...
11
votes
0answers
415 views

Who owns the intellectual property of Thinking Machines today?

Who owns the intellectual property regarding the Connection Machine and other products from Thinking Machines? I believe the remnants were bought by Sun, so possibly Oracle, but does anyone know?
5
votes
2answers
234 views

What was the first system to use flash or beep codes as a diagnostic?

It has long been the case that computer systems can signal serious faults using a series of beeps or flashes, where such faults occur too early in the boot process for them to be communicated in more ...
20
votes
3answers
787 views

What software stack could I use to get X10 (the version of X before X11) up and running on a modern system?

"What's the story behind the name "X11"?" showed up in the sidebar while I was browsing stackoverflow earlier and I noticed the question getting some high-signal answers, so I added a ...
5
votes
1answer
526 views

I have installed MS-DOS 6.22 on Virtual Box, do I have an ISA bus or a PCI bus?

I have installed MS-DOS 6.22 (released in 1994) on Virtual Box, and I want to know if Virtual Box is emulating an ISA bus or a PCI bus. The settings for my virtual machine don't show any information ...
12
votes
1answer
876 views

Using a 360k (DD 5.25") floppy with Windows XP?

My PC XT clone went up in smoke (literally) the other day. I salvaged the half height 5.25" double density floppy drive though and dropped it into an old 1.8 ghz AMD tower I had laying around. Plan ...
14
votes
2answers
1k views

Who decides what is the memory address that the CGA video buffer will be mapped to?

In DOS, the memory mapped IO base address for the CGA video buffer is 0xB8000. So when you write to 0xB8000, you are actually writing to a buffer in the CGA card itself and not to RAM. What I want to ...
5
votes
2answers
1k views

Why the “jmp” instruction is not working?

I have written the following program in debug.exe: 1165:0100 mov ah, 09 1165:0102 mov dx, 107 1165:0105 int 21 1165:0107 db 'Hello World', 0A, 0D, '$' 1165:0115 jmp 1165:0100 However, when I ...
59
votes
1answer
9k views

What's the story behind the name “X11”?

To this day on Linux configs and startup scripts for the GUI system are stored in /etc/X11. I remember this name appearing alone, or alongside others - XFree86, X.org, X - for as long as I had contact ...
9
votes
1answer
2k views

How to write directly to video memory in MS-DOS?

The base address for the video memory in MS-DOS is 0xB8000. I am trying to write to this address using debug.exe, but I am getting an error: 1165:0103 mov [b8000],ax ^ Error
-6
votes
4answers
871 views

What is the starting address pointed by Stack Pointer in PDP 11?

To which memory location does the stack pointer point at the beginning of the program in PDP 11? And what can be the end address the SP can point to before overflow occurs?
30
votes
6answers
3k views

What was the purpose and history of the C64's special keys?

I never had a Commodore 64 but I've always been curious what the purpose and history of some of the special keys were. In particular: C= Run/Stop Clr/Home Restore I'm mostly used to the standard ...
21
votes
9answers
2k views

Why did CP/M and MS-DOS use the BIOS instead of their own drivers to access hardware?

Modern versions of Windows (and other modern operating systems I suppose) have their own drivers to access hardware. But as I have read, in the old days, if CP/M or MS-DOS wanted to access hardware, ...
15
votes
2answers
931 views

How old-computer emulators work?

I'm wondering how old-computer emulators work. I can think of two possible approaches: "hardware" approach - like a set of components that exactly act as low-level hardware elements. I mean a bus ...
11
votes
3answers
2k views

What do the “byte-select signals” in the 68000 do?

Got a question about how the 68000 addresses memory. Wikipedia says: The 68000 has a 24-bit external address bus and two byte-select signals "replaced" A0. Here is an image of the chip's pins: ...
15
votes
4answers
2k views

Why is the serial port driver named “/dev/ttyS#”?

Based on my understanding, a tty means a computer terminal/teletype, and that /dev/ttyS1 is the driver for serial port 1/COM1 (or more accurately, a driver for UART chip 1 I suppose). But I don't ...
19
votes
2answers
2k views

Blue and yellow stripes on the screen when loading from tape on ZX Spectrum

When loading a program from tape on ZX Spectrum you could see those blue and yellow stripes around the splash screen. I might be mistaken but I believe those were even sometimes used for quite ...
14
votes
1answer
2k views

Why BGR color order

Blue Green Red (BGR) byte ordering exists in a few image processing libraries "for historical reasons", mostly because it seems to have been a Microsoft standard. Does anyone know the historical ...
50
votes
5answers
10k views

Why did base64 win against uuencode?

From the the two methods of encoding 8-bit data as human-readable ASCII, for a time, uuencode format was more popular. USENET 'binaries' groups were filled with uuencoded posts with whatever goodies ...
12
votes
4answers
561 views

Is there software that will run across multiple Commodore 8-bit machines without modification?

I noticed in some of the answers in this question that the Commodore 8-bit line apparently used a jump table at $03xx for entry into the kernel ("kernal" for the pedantic) routines. Figuring that the ...
11
votes
2answers
472 views

Which retrocomputers were dominant in Australia and New Zealand in the 1980s?

Australia and New Zealand are somewhat unique among large, developed, economies because they bridge the culture of (mostly) the West with the geography of the East. I am curious how this may have ...
5
votes
1answer
272 views

Strange visual behaviour on SGI IRIX

I've installed IRIX on SGI Octane and have screen looking like this: (I mean the stripes on all elements of the screen, which doesn't seem as a result of CRT monitor - the screen looks normally on ...
8
votes
2answers
351 views

How many gates does each chip in OCS have?

According to Wikipedia, the original Agnus has 21000 transistors. How many gates would this be? (assuming there's a straightforward way to convert between gates and transistors). What about Denise, ...
21
votes
7answers
1k views

What implementations of BASIC had a robust flood fill operator?

When I learned BASIC on Elektronika BK, I got fascinated with the flood fill (PAINT) operator: how does it know to get to all nooks and crannies of the shape to fill? I've devised an algorithm, tried ...
9
votes
3answers
1k views

Can artifact color mode create 262,144 colors on Amiga OCS?

This is as a follow-up to my previous question on artifact colors and the excellent answers provided there. The images below show a simple example of artifact colors generated using a single bit-...
13
votes
5answers
595 views

When did energy saving start to become important?

There was a time where computers often just stayed on all the time. Computer monitors did not have power save functions... they were either on or off. Processors such as the 6502, 68000, 8086, 286, ...
11
votes
3answers
610 views

Why was OCS low resolution limited to 6 bitplanes?

I'm looking for information whether there has ever been an official statement by Commodore back in the days on why the Original Chipset was limited to doing 6 bitplanes only when running in low ...
9
votes
2answers
629 views

ZiLOG Z80 fan-out (CMOS version, Z84C0006PEC)

I am building a z80 based 8 bit computer, and I really don't want to fry my chip. I was looking at this datasheet, but I couldn't find the fan-out specified. There are some electrical characteristics ...
13
votes
2answers
1k views

What is the “standard” way to implement KERNAL hooks on the C64?

The C64 kernel (or KERNAL as it’s known in the C64 community) routines work via a jump vector table stored in page $03xx. A common programming paradigm to create something like a "device driver" would ...
7
votes
3answers
790 views

How were terminals connected to a PDP-11 computer?

This is how I think terminals were connected to a PDP-11 computer: A PDP-11 computer had only one port that you can connect the console terminal (/dev/console) to, and if you want to connect more ...
8
votes
1answer
640 views

Can anyone help name this game?

This is certainly a long shot... this game has evaded my searching for years and I would love to have this mysterious game named once and for all. It came out prior to 1997 (possibly earlier this is ...
15
votes
1answer
488 views

Does anyone know the specific differences between the NES-001 (NTSC) motherboard revisions?

On each Motherboard of an NES-001 (NTSC) there is a code: NES-CPU-xx These range from 04 to 11 (I think) I would like to know if these are all of the revisions of the NES and what major differences ...
15
votes
3answers
1k views

How did the IBM PC handle multiple physical devices serving memory at the same physical address?

I'm trying to figure out how the IBM 5150 PC handled the case where multiple physical devices (memory chips) were mapped to the same address within the 8088's physical address space. The closest I've ...
7
votes
2answers
640 views

Creating Null Modem Connection between two C64s?

Trying to establish a null modem connection between 2 C64s using 1 Commodore 1660 300 Baud modem and 1 Commodore 1670 1200 Baud modem. Does anybody have detailed instructions on how to configure the ...
20
votes
1answer
751 views

What is the difference between the “Return” an “Enter” key in the VT100 terminal?

What is the difference between the "Return" an "Enter" keys in the VT100 terminal:
16
votes
6answers
4k views

What PC “Clone” technology standards were introduced by clone manufacturers?

IBM famously created the PC standard with the introduction of the first IBM PC in 1981. IBM also extended the standard with the introduction of the PC/AT (1984) and the PS/2 line (1987). However, by ...
15
votes
6answers
2k views

What monitor did Atari recommend for its 8 bit product line?

I am curious what Atari recommended to users as an appropriate monitor for their 8 bit computers (400/800/800xl/etc). For example, my Commodore 64 pairs nicely with a Commodore manufactured 1702 or ...
9
votes
1answer
565 views

What was the difference between “Video Low” and “Video High” on the VIC-20?

I was reading about the Audio/Video port pinouts of the VIC-20 and I noticed that pin 4 is VID L and pin 5 is VID H meaning Video Low and Video High, respectively. I'm familiar with luma, chroma, etc....

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