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15
votes
7answers
3k views

Cost of PC vs. Amiga 500 in Europe

Based on Commodore sales figures, and other historical claims, the Amiga achieved its peak popularity in 1990-91, with European sales being the leader. By 1990, with the rapid fall in PC clone prices, ...
10
votes
4answers
1k views

Anecdote in Weinberger's Psychology of Computer Programming: is it ARPANET?

Gerald Weinberger, in the 1971 book The Psychology of Computer Programming, gives the following anecdote: The numerous stages [of reporting?] can produce interesting effects, as a result of filtering ...
7
votes
3answers
3k views

Identifying motherboard and CPU

Anyone ever see a CPU with this identification? Or does anyone know what kind of motherboard this is? Thanks
15
votes
1answer
2k views

Why did Atari floppies run at 288 RPM?

Atari floppy drives for the 8-bit series, the 810 and 1050 specifically, ran at 288 RPM rather than 300. I can't imagine why this might be, and my google-fu fails to turn up a reason. Worth noting ...
15
votes
0answers
371 views

When was an image of an apple first used to promote the APL language

The APL community is contemplating the adoption of a common logo but some are worried about trouble from Apple lawyers. Now, IBM and others have been using apple motifs in promoting APL for a long ...
6
votes
1answer
544 views

Did XEROX 630 and 645 run CP/M?

My late father owned two bulky and havy word processing systems manufactured in the 1980s or early 1990s, a XEROX 630 and a XEROX 645. Both had similar cases featuring an integrated Diablo 630 daisy ...
4
votes
0answers
209 views

80's Atari-800 game where pieces on a board move automatically according to preset rules

The game I'm thinking of was played on a grid of squares (somewhere in the range of 8x8 to 10x10) where each player put down pieces on their side of the board (I think it was white on the bottom rows ...
2
votes
0answers
166 views

Did other Acorn keyboards use two-shot molding?

The BBC Micro hardware specification includes the clause: The legend on the keys will be achieved by two-shot moulding This is a process by which the glyphs are made to run all the way through the ...
2
votes
1answer
165 views

Why 8086/8088 has OF in a high Flags byte?

In 8086, OF is put not into low Flags byte as other flags but separated in the second (high) byte. This is followed then in all the x86 line. Beside the possible historical reasons, this looks highly ...
12
votes
2answers
865 views

Slowdowns in CBM BASICs between 4.x and 7.x?

I recently came across a thread suggesting the versions of CBM BASIC on later machines, I believe the Plus4 and 128 were mentioned, were significantly slower that earlier versions. I haven't found ...
5
votes
1answer
881 views

Why would a laptop freeze randomly after running fine for a while?

I have a Compaq LTE 5150 laptop from 1995 on which I've installed Windows 3.1. It runs fine, and I'm able to use the computer for Word, Lotus Organiser, etc with no issue for a period of time and ...
8
votes
1answer
512 views

Is "scroll tearing" a symptom of scanline interrupts taking too long?

I was trying to implement multiple LYC IRQs to implement faux parallax effects (like in Game Gear Shinobi), and my method was to begin LYC interrupts at a particular scanline, say about halfway down ...
2
votes
2answers
253 views

Is the source for the original Elite public?

Is the source code for the original Elite public? Even after all this time, I'm still flabbergasted at how hard they pushed the BBC Micro, and what they achieved. A commentary on the disassembly would ...
2
votes
1answer
220 views

How do you start a minimized MS-DOS session on Windows 98 SE?

How do you start a minimized MS-DOS session (i.e., launch a Command Prompt window that is in the minimized state) for Windows 98 [version 4.10.2222]? I thought the solution would be: start /min But ...
15
votes
1answer
276 views

What happened to IntelliFont (i.e. Amiga vector fonts)?

One of the oft maligned weaknesses of AmigaOS 1.x was that the included bitmap fonts were not very good, especially when compared to those included with Classic Mac OS. Commodore closed this gap with ...
12
votes
3answers
2k views

Does 10BASE-T need more sophisticated electronics than 10BASE5/10BASE2?

In a discussion on the history of Ethernet and 10BASE5, Stefan Skoglund commented Was 10BASE5 a mistake? One reason why 10BaseT became possible is Moores law (and the same for the other designs after ...
2
votes
2answers
166 views

Installing 98SE without USB/CDROM to IDE drive - Invalid System Disk

I bought a Compaq LTE 5100 that came without a drive. I got a replacement caddy from an Armada and the drive is recognized in BIOS (60GB drive, listed as 8GB as expected). What I have: a stack of ...
9
votes
2answers
229 views

What was the use case for the 96-column punch cards introduced with the IBM System/3?

Shown here at the Computer History Museum site (*) Not sure when they were introduced but it was before optical scanning (barcodes) was possible / affordable, maybe even before magnetic stripe ...
5
votes
1answer
260 views

What were the characteristics of the Siemens 8160 and 9750 terminals?

An answer to a recent question https://retrocomputing.stackexchange.com/a/22332/4274 referred to the Siemens 8160 and 9750 terminals, which struck me as interesting enough to ask about separately in ...
2
votes
1answer
179 views

Were any form-based applications designed for more than 80 columns?

The traditional standard display for business computers was 80 column text (with either 24 or 25 rows). Business software, roughly speaking, falls into two categories: Horizontal applications like ...
16
votes
2answers
2k views

What made the Amiga "Genlock-able"?

Right at the moment the original Amiga A1000 was being introduced, Commodore was already advertising its ability to use a Genlock peripheral, and promising that Commodore's own Amiga 1300 Genlock ...
27
votes
2answers
4k views

Why did the Z80 break 8080 compatibility?

Although the Z80 is nearly fully backward compatible with the Intel 8080, there are minor differences such as the Z80 handling the parity flag differently with certain operations. Why? Would providing ...
28
votes
13answers
3k views

BYTE Magazine outside the U.S

BYTE magazine was a well-known computer periodical published in the U.S. that had a successful run from the late-1970s to the 1990s. As such, it was not only a regular fixture on U.S. newsstands, but ...
13
votes
3answers
4k views

What does this 1970s punched-card format mean?

The 1974 Texas Regional Programming Contest (a predecessor of the ICPC) describes an input format: A room description will be contained on a single card with the format: (1X, I2, 2X, 12 (A1, I2, 2X))....
3
votes
2answers
204 views

How does the serial port on the RC2014 get addressed?

I see on the schematic that /M1 and A7 go to CS0 and CS1 respectively. As I recall, both of these need to be high for the chip to be selected. And A6 goes to CS2, which needs to be low for the chip to ...
1
vote
2answers
512 views

Was server operating systems ever created with a terminal operating system in mind? [closed]

I have always thought that in the case of Microsoft's server operating systems that they were created with the idea that the end-user of those servers would use Windows. I also thought the same for ...
0
votes
1answer
145 views

How the technology keeps improving [closed]

How does the technology keep improving despite having everything discovered already? I mean the same sized chips and electronics are used from year to year but with every new version of the main board ...
10
votes
2answers
1k views

The march of progress before microchips

Throughout the 1980s and 1990s, computer power seemed to increase so drastically that pretty much any computer you could own rapidly became obsolete. Such were the strides in available power and ...
17
votes
3answers
5k views

How did the Commodore 64 show a picture while reading cassette?

I was watching this video just now https://www.youtube.com/watch?v=I0YmJluYb6Q&ab_channel=NostalgiaNerd on things that early home computers displayed on the screen while reading cassettes, and ...
5
votes
1answer
216 views

Audio cassettes on TI-99

One of the features of the Atari machines was that the left audio channel on the cassette was connected through to the television speaker. This was used to produce things like "Conversational ...
8
votes
1answer
831 views

Why did IBM want to keep ICL alive?

According to https://en.wikipedia.org/wiki/International_Computers_Limited International Computers Limited (ICL) was a British computer hardware, computer software and computer services company that ...
10
votes
4answers
1k views

Could the Z80 do interference-free video as the 6502 could?

Technically this isn't just about video since it applies to any regularly scheduled DMA¹ from a non-CPU subsystem, but video is the most common application of this technique so I'll use that as the ...
3
votes
2answers
182 views

How to get the inner dimension for Amiga Intuition window with GIMMEZEROZERO Flag?

I am sizing the contents of my Intuition window relative to the space available in the window. A regular window exposes its initial dimensions via my_window->Width and my_window->Depth, however ...
6
votes
4answers
1k views

What was the first Ethernet hub?

An Ethernet hub is – well, Wikipedia does an impeccable job of summarizing what it is: An Ethernet hub, active hub, network hub, repeater hub, multiport repeater, or simply hub is a network hardware ...
20
votes
5answers
6k views

Was 10BASE5 a mistake?

https://en.wikipedia.org/wiki/10BASE5 gives a succint but vivid description of the physical layer of the first version of Ethernet and its subsequent replacement: 10BASE5 (also known as thick ...
1
vote
1answer
178 views

How does RETN return from NMI on the Z80 in the event of nested NMI?

I was trying to learn how the Sega Master System works. The NMI occurs when the pause button on the console is pressed. So I wrote an NMI handler that makes a beep when the NMI occurs, then waits for ...
20
votes
6answers
9k views

How did early computers handle mice?

Early computer mice worked by sending a series of pulses; the more rapid the movement, the higher the frequency. How was this handled at the computer end? At one level, it sounds easy: just run a loop,...
1
vote
0answers
94 views

MS-DOS Bear/Teddy Bear Spooky Halloween game?

In about 1993-4 I played a (probably free or shareware) MS-DOS game about a bear/teddy bear entering a house which was "spooky", I believe related to Halloween. Graphically it was primitive, ...
15
votes
2answers
1k views

Who considered multimedia capability a liability for a business computers, and why?

For technical reasons, business computers of the late '70s usually had little multimedia capability. There have been modern claims (e.g., in the comments on this video) that such capability was ...
2
votes
2answers
236 views

Commodore 1352 mouse converter

My Commodore PC30-III can only handle a Commodore 1352 mouse, but it is practically impossible to buy one. I own a couple of Amiga and serial PC mice that if I plug in, the buttons seem to work, but ...
3
votes
0answers
116 views

Looking for a medieval store-management game on the TRS-80 Color Computer, might have been code from Rainbow magazine

Crossposted from the Science Fiction and Fantasy Stack Exchange, where it's been unanswered for almost two years. I'm trying to track down a game I remember playing on our Color Computer 2 (it could ...
0
votes
1answer
127 views

How are Apple II address lines mapped to DRAM rows and columns?

The Apple II's MK4096 (4 Kbit) and MK4116 (16 Kbit) DRAM chips have 6 and 7 (respectively) address line inputs that are multiplexed: first the row address bits and then the column address bits are ...
0
votes
0answers
155 views

What was the first PC-compatible computer to have a DRAM controller?

The original IBM PC used a timer from the 8254 PIT and a channel from the 8237 DMAC in order to refresh RAM with dummy reads (and I think used NMI to signal parity errors.) I'd like to know when PC's ...
4
votes
1answer
234 views

"GAZE" GUI Organizer program?

In the early-to-mid '90s there was a GUI-based DOS organizer-like program, called GAZE, from which you could launch software and games which had an eyeball in the corner that followed the cursor as ...
4
votes
2answers
1k views

What was the first CPU/FPU without a hardware square-rooter?

The first programmable, electronic, general-purpose digital computer, ENIAC had a "square rooter": five of the accumulators were controlled by a special divider/square-rooter unit to ...
7
votes
1answer
247 views

Are there any other historical traces of the earlier versions of the Alternate Multiplex Interrupt Specification by Ralf Brown?

I'm a fervent user of the Alternate Multiplex Interrupt Specification for 86-DOS systems, a method using a common set of multiplexer interfaces over interrupt 2Dh. It was originally developed in the ...
32
votes
1answer
11k views

Why did the NES not allow rotated sprites?

I'm taking a look at the chapter on sprites from a NES programming guide at famicom.party. There is a little table which describes what the different sprite attribute flags do; 7 Flips sprite ...
4
votes
1answer
152 views

Does the Apple II's non-linear frame buffer layout help DRAM refresh?

The Apple II uses non-linear frame buffers for text and graphics. Rather than storing each line in sequence at lines 0-23: $400, $428, $450, $480,¹ ..., $7D0 it stores them at lines 0- 7: $400, $...
7
votes
1answer
241 views

What causes the horizontal lines at the left of the Atari 2600 screen?

I occasionally see video captures of Atari 2600 games that have horizontal bars down most of the left-hand side of the screen, as in this video of Star Voyager by Imagic: It's not clear to me whether ...
4
votes
1answer
509 views

Why was the original Legend of Zelda initially released on floppies?

The Legend of Zelda for the Famicom was apparently released in 1985 on floppies as a launch title for the "Famicom Disk Station" peripheral, only used in Japan due to the high prices of ...

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