Hot answers tagged

83

With a powerful enough microscope, you can see each transistor. Reverse-engineering silicon then boils down to carefully removing each layer (ceramic or plastic to expose the chip, then each metal layer), taking detailed photographs, and figuring out what each part does. For CPUs of the era, this was already possible in the early eighties. Ken Shiriff does ...


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.


53

(More of a memory dump related to Stephen's answer) At a time when ICs were of low complexity (compared today), could you actually see each transistor on the silicon and reverse engineer it? Yes. Just try it yourself. Take some 1980s TTL, like a 7400 - I'm sure you find some on old boards - and crack it open. Usually it separates well from the plastic. Put ...


53

it seems to be a simple bounding box check, as shown here from 6502 code disassembly, collision check between ship and saucer HitDetShip: L6A63: CPX #$01 ;Is object 1 not the player's ship? L6A65: BCS HitDetSaucer ;If not, branch. L6A67: ADC #$1C ;Ship hit box 42+28 = 70 X 70 from center. HitDetSaucer: L6A69: BNE ...


35

In 1982 the original 400 and 800 were on the market. These were expensive machines to implement. Even the low-cost 400 was significantly more complex and expensive than something like a VIC-20. Say what you will about the VIC-20, it was cheap. And it proved that the #1 selling point for a computer was its price. And then came the 64. So as Commodore started ...


33

There are two elements: The background The sprites The background is very straightforward: The vanishing point never changes so you have one graphic with a checkerboard in perspective. That graphic takes 2 bits per pixel so that you have the 2 checkerboard colors and the edges of the field color. It just needs to be the width of the screen + 4 tiles (2 ...


32

It's worth noting what you can see, and what you can't. First, you cannot see any feature that is much smaller than the wavelength of light that you are using. In 1995 I designed a chip for my Master's thesis in 1.2um technology; features are clearly visible under microscope. Features in 0.5um technology might be visible, but by 1997 0.25um technology was ...


30

The physical design of the Atari 800 was radical, but not for reasons related to the aspects you highlight. As others have commented, using multiple boards for a system was pretty standard at the time. S-100 systems for example were based on a backplane, with system features implemented on multiple boards connected to that. (The Atari 400 and 800 were ...


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....


26

The gameplay can be implemented without any 3D calculations (or very little, depending on your definition of 3D calculations): The checkerboard never rotates, so it can be drawn using affine segments and fills (y = ax + b); the players never get close enough to the edges (on the goal sides) for the vanishing point to be an issue. The checkerboard isn't ...


26

The Amiga OCS was not exploited in the same way as the C64's VIC-II simply because the OCS was designed from the beginning to support rapidly changing video output modes. Unlike the C64, and most 8-bit machines, the Amiga's display coprocessor (the "Copper") existed to allow display mode updates to occur many times during the raster. For machines like the ...


23

If one game would qualify, that would be Alien Breed: the game switches from PAL to NTSC rapidly to emulate a damaged CRT display (extract of longplay at this point). A PAL to NTSC switch should occur at the top of a frame, so doing that in the middle of a frame can be considered like exploiting a bug. Now, whereas games didn't push the tricks too far, that ...


19

De Re Atari describes the cassette boot protocol, which helps understand why bootloaders were (nearly) always used. In cassette boot mode, the operating system reads a record from the tape recorder and loads the following information: byte 2 gives the number of records to load (up to 256 records, each containing 128 bytes, so 32 KB in theory) bytes 3 and 4 ...


19

Most classic computers will work fine on a TV with proper composite inputs. You want to make sure your TV has aspect ratio selection as many simply horizontally stretch the 4:3 image to 16:9. As for Atari's, it will depend on which model you have and what cabling you have. I've very successfully run Atari 800XL and 1200XL systems with LCD TVs using the ...


19

In the end, I decided that it had to be easier to take the keyboard apart than to de-solder the 4051's and so I carefully removed the 18 tiny screws from the back of the keyboard. It wasn't nearly as bad as I expected (I was concerned that I was going to have springs everywhere). After disassembly I fired up the Atari to try and see if I could get the A ...


19

I can only add to the other answers with observations and memories, some of which come from owning an Atari 800 in the time period you're asking about. First, notice the names flying around in the space of only a few answers: IBM, Apple, VIC-20, Commodore 64, TI. Add to that list TRS-80, Timex Sinclair, and the Coleco Adam (released in 1983), and more. In ...


19

They are not really inductors. They are EMI noise filters for suppressing electromagnetic interference that conduct out of the unit via the wires. These kind of EMI filters usually have two ferrite beads and a capacitor in a T configuration, to filter both incoming and outgoing interference. The type of the filter is ZJS5101-02 according to ST manuals. ...


17

If you're willing to spend some money, there are some nice options using the Atari's SIO port (the big trapezoidal plug on the side). Maybe the most flexible option is the SIO2PC adaptor, which lets you connect your Atari to a PC via serial or USB connection. This lets you do things like access a directory on your Mac or PC directly from the Atari, and ...


17

I can only really answer from my own perspective, and I only wrote real code (other than simple BASIC programs) on an Atari over the last couple of years. IDE Used In terms of classic tools IDEs were relatively light compared to tools you get today. I worked using Devpac 3, which is a good assembler that includes some useful features and a debugger. STOS ...


17

And now here are some really non-trivial hacks played with amiga chipset: 7-bitplane ECS hack: https://groups.google.com/forum/#!topic/comp.sys.amiga.misc/HQBzx6E0K1Y (see the first message in the topic) When you fill register $dff100 with value which has the number of bitplanes specified as 7 (lo-res) something strange is going on. On screen you will ...


16

Looking for either "rose.neo" atari or "rose.pc1" atari in Google images with an exact requested size of 320x200 yields this result, which seems to match your description pretty well. Could it be that one? EDIT #1 Here is a better version from Demozoo. EDIT #2 The original Neochrome file can be downloaded from this page.


15

There are versions of the Atari 520ST, and perhaps the 1040ST, that differ in having many discrete inductors attached at the I/O port lines for serial, parallel and floppy ports. Essentially all later ST have them. The first picture shows a C070115 Rev. 2 ST board wich is about the oldest in general availability. The second is a C070243 Rev. C which is the ...


14

I used to program on the Atari about 20+ years ago, so I might be a bit rusty on the subject. Also I used to mainly write demo effects and music, so I wasn't working on core game development directly (other than writing music for some). IDE is a more modern concept, so you probably won't find one on the platform itself, but there are some out there for ...


14

MOS was renamed to Commodore Semiconductor Group (CSG) sometime after Commodore bought them in 1976. After Commodore folded in 1994, the CSG division was bought by its former management and renamed to GMT Microelectronics (Great Mixed-signal Technologies). They continued with design, manufacture, and marketing of analog and mixed-signal power management ...


14

Ignoring the copyright issues of such an endeavor, you're going to have a very hard time of ripping audio in a conventional sense. Old games don't store their sound effects and music as waveforms like modern PC and console games do. This is because both the audio hardware on old computers and consoles was much more limited, and because there wasn't enough ...


14

At that point in time, Atari had separate divisions for the Home Computer market and the Consumer Electronics, or console, market. There was a lot of competition between the divisions. The Consumer Electronics division was the pride of the company due to all the cash that was rolling in thanks to the Atari VCS(2600), and it seems there was a bit of hubris ...


13

The beep comes from the OS ROM, and it is actually derived from the timing of the start and stop bits of each byte shifted into POKEY, this is determined from the interaction of the interrupts generated. The frequency output is nominally half of the operating bit rate, e.g. approximately 960Hz for a 19200 baud transmission (e.g. from a disk drive at normal ...


13

The primary personality was Shiraz Shivji, a member of the C64 team who became the lead designer of the Atari ST. As per the linked Wikipedia article, he and three others — Arthur Morgan, John Hoenig and Douglas Renn — were accused by Commodore of intellectual property theft, specifically around the disk drive in Commodore's aborted Z8000-based UNIX machine, ...


13

Yes, reverse engineering of chips with a conventional optical microscope in the late 1970s and early 1980s is generally possible. Although of course, there are limitations. Firstly, the number of wiring layers is important - already two layers of metallization and two layers of polysilicon make reverse circuit design much more difficult. Secondly, chip traps ...


12

If bit 0 of location 842 is set then the keyboard scanning routine immediately returns 0x9B which is the code indicating the ENTER key has been pressed. In short, a surprisingly literal effect. The keyboard scan is part of the "OS" ROM built into the machine. There's a source listing I'll excerpt from: Atari 800 ROM OS Source Listing ICAX1Z is a zero ...


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