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66

Both the Sinclair ZX Spectrum and the Pac-Man arcade machine used the Zilog Z 80 CPU. Pac-Man's display was slightly larger and vertical at 224×288 while the Speccy's was horizontal at 256×192. The Speccy did not have hardware sprites or pixel-addressable colours. The original 48K Speccy only had "1 bit" beeper sound though later models had an AY ...


61

Pong. I've lived in the UK for many years and never heard it called Ping! That is news to me. Now, when talking about the video game called Pong, we call it Pong.


60

Having the display vertical reduces the width of the cabinet. This means that a game machine can be fitted into a smaller space in a pub/bar, or in an amusement arcade where machines are in rows you can get more machines (potentially a third more) into the same space. One-third more machines means one-third more revenue. The orientation may also have been ...


51

There are only seven fruit in Pac-man. The way the game calculates the number of fruit to draw is as follows: LD A,(#4E13): Load the level number (at memory address 0x4E13) into A. INC A: Increment A. CP #08: Is A < 8? JP NC,#2C2E: If not, jump to large-number fruit handling code. LD DE,#3B08: Load the address of the cherry into DE. Start the fruit-...


39

The way I understand it, ROMs are like virtual games, Not really. ROMs are a piece of hardware storing a bit image. Like a disk, a tape or a punch card. It holds an image of the game's software. and emulators are like virtual game consoles, or handhelds. Basically yes. What I don't understand is how there are ROMs for arcade games, which don't have ...


38

This isn't a deliberate animation, it's an accident of the way the screen is being photographed, combined with the fact that a Donkey Kong arcade machine uses a CRT turned on its side. A typical CRT draws an image by drawing many successive horizontal lines, starting at the top and working towards the bottom. The "refresh rate" indicates how many times ...


35

The reason for this glitch is rather obscure; it's not surprising that the developers didn't catch it. It all starts with the tunnels on the sides of the screen. These tunnels allow Ms. Pac-man and the ghosts to move from one side of the screen to the other. But, somewhere in development, somebody decided that the ghosts were moving too quickly through them. ...


35

CRTs don't have pixels, they don't work that way. Also, arcade monitors expose all the picture controls at the back so it is possible to adjust them quite extensively. Operators would have made sure that the picture was the right shape and in focus near the edges. Since the controls are all analogue and no-one bothered to measure the display geometry the ...


35

Most of the time, game coders are not going to program an A.I. just to show the demo so the moves are pre-recorded, and generally the demo ends quickly with the main character dying/exploding (maybe not to show too much of the level) To record the moves, the programmers probably added some piece of code to log all player input along with the exact frame ...


33

Ken's answer is close but not quite right. On the real arcade hardware the signal sent to the CRT monitor is read directly from RAM as the electron beam scans over the screen. That means that whatever is shown on screen is whatever is in RAM at the moment the beam passes that area. The game's CPU takes a few frames to draw the entire play area (the girders, ...


33

To understand what was going on with licensed and unlicensed ports of popular arcade games in the 1980s, you have to understand two critical factors. The video gaming culture of the time, and the preeminence of coin-op arcade games. The role of trademarks and legal trademark protections, which was the more crucial law pertaining to arcade game ports at the ...


30

Yeah, I remember this arcade game, too. My brother was quite good at it, so I saw it a lot. Could it be Space Encounters? It was a full-sized arcade cabinet with an aircraft-yoke type controller with fire buttons on the tip of the yoke. I seem to recall rubbery handles on the yoke that looked like they came from a kid's bike handlebars. This controlled ...


29

Dig Dug stores the positions of objects in tables in memory. There are two tables for this: an enemy table containing the positions of up to four Pookas and four Fygars, and a rock table containing the positions of up to six rocks. There is also a table containing tunnel data, but this is stored in a different way. The game divides the playable area into ...


27

I actually did this with pinball machines in 1980-ish. Getting 3-5 games before the coin was lost wasn't impossible, and some of my friends did better than that.


27

According to Atari co-founder Nolan Bushnell, Pong was marketed as "Ping" in the UK. He said so in this 1982 BBC interview ("because evidently Pong is not a good word in England"), and repeated it 16 years later in this interview with German online magazine Telepolis. If nothing else, Bushnell is probably the source of the story you heard....


22

Space Invaders uses a simple display format where bytes are read from memory in order via an address counter, and shifted out via a shift register. Timing is controlled by discrete hardware. The video hardware has priority over the CPU. When it needs to read a byte it asserts the 8080's READY signal, giving it exclusive access to the memory bus. This can be ...


21

The other answers already covered a lot, but there is something else that is important but which hasn't already been addressed in detail: Despite appearances to the contrary, arcade machines are quite frequently not built with unique hardware. For example, the hardware originally designed for Galaga was used for several additional games, including well ...


21

It's difficult to be sure that there was never a system in use that was vulnerable to this trick, but certainly there were systems available from a very early stage that weren't. This coin acceptor is typical: it uses a ratchet mechanism that engages the moment the coin is accepted to prevent reverse motion.


20

(From the perspective of the electronics, that means the displays were drawn sideways.) Not necessary. There is no inherent reason for drawing sideways. A video circuit can easy be made for either, as line width and number of lines can be defined either way. This is especially true for early games, where electronics were rather special to type and so was ...


19

The 6502 accesses the Atari Math Box, via a pre-defined memory map and address decoder,[1§I] as a memory-mapped I/O device.[1§IV] The top four bits of the External Address Bus are sent to the address decoder to determine whether to activate the high-score module, the POKEY module or the Math Box for a given operation.[1§IV] The bottom five bits of the ...


17

You could fool purely mechanical devices with mechanical tricks. One trick I have used when a kid, was with bottle caps. We wore them out underneath our shoes, until they were the size of a coin, fit for a bubblegum machine. But I get the feeling that with the earliest introduction of electronics into slot and arcade machines, the electronic sensing of the ...


16

I can personally confirm this worked on at least some video arcade machines in the 80s, when I was young. I can vividly remember being at an arcade at one point, and losing a quarter in the machine. Instead of refunding my money, the attendant came by and gave me a free game with the use of a coin-shaped slug welded to a long, flexible wire. It looked like ...


16

For space invaders what happens is the game has short list of movements (11 in ROM but only 10 are used) left and right or stay still. If there is no bullet in flight the player fires, each time the bullet fires the next direction action is pulled from the list and the player starts moving in that direction. The time of flight of the bullet acts as a timer, ...


14

The three CPUs were designated as follows: CPU 1 - Main game logic and control of the other two CPU 2 - Graphics and enemy movement CPU 3 - Sound The three CPUs communicate via shared RAM. CPU 2 and 3 perform start-up checks (such as a ROM checksum) and then go into infinite loops, with all activity happening inside interrupts triggered by CPU 1. CPU 2 is ...


14

Did arcade monitors have same pixel aspect ratio as TV sets? Short answer: No, not necessarily. Long Answer: To start with, 'Title Safe Area' is an idea to define the parts of one transmission to be displayed even if any of the many receivers is maladjusted. It's nothing inherent to the TV signal or its definition, it's a safeguard against less than ...


14

(Links are to the pertinent points in the video) 00:15 Казахскся. ССР. A.D.2048 "Kazakh SSR A.D.2048" (Russian script, Latin date) 02:49 Сиби́рь 1 "Siberia" (Russian script) 06:24 געלראב "Balrog"2 (written backwards and mis-spelled3) (looks like some kind of Aramaic or Hebrew script; Hebrew shown above) 11:03 Amazon "...


13

Midway's port of Western Gun, known as Gun Fight in the West is the first arcade game that used a microprocessor (the same Intel 8080 used with Space Invaders). The original Western Gun release in Japan used Taito's Transistor-Transistor Logic chip (possibly one in the 7400 chipset family, as used on many of Taito's boards). Dave Nutting made the decision to ...


13

Galaga has specialized graphics hardware that draws 64 individual sprites, so to update a screen full of objects you only need to update 256 bytes at the most. The star field is generated completely in hardware with a LFSR (linear feedback shift register), and there is a 8x8 tile map to draw the score and any other text. I'd guess the Galaga CPUs are ...


13

Yes they existed, and they were produced by Sega, with the interactive movie Time Traveler being the most common though Holosseum, an upgrade kit for Time Traveler, is probably the fighting game you are thinking of. It wasn't a real hologram, obviously, but just a 2d image projected via a concave dome-shaped mirror to give the appearance of floating in ...


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