3 ms·

It looks simple & short, but on the other hand I've checked the repo and it has 1k commits, so probably not THAT simple I have some small, 4fun experience with

It looks simple & short, but on the other hand I've checked the repo and it has 1k commits, so probably not THAT simple I have some small, 4fun experience with compilers and I do wonder - how people start with game emulators? what are the basic concepts? what is the easiest hello-world game to start w/?

zeta0134 3y ago
The typical hello world is actually a CHIP 8 emulator, which is a type of VM that ran on an old calculator, the specifics of which elude me. It's got a tiny memory space, simple instructions and a handful of features, so it's the sort of thing you can get up and "running" with minimal effort. It lets you explore the high level concepts involved in running a "guest" system on some hosts, and tickles the challenge of synchronizing the timing and dealing with video and sound, without being overwhelming the way a physical console can be.
- tester756 3y ago
  Calculator sounds like a great idea! thanks
  - khedoros1 3y ago
    "Calculator" doesn't quite cover it. CHIP-8 was developed to run on the COSMAC VIP home computer, and later similar ones like the Telmac 1800, which were shipped as kits for users to build at home.
khedoros1 3y ago
> how people start with game emulators? I had some Computer Organization and Architecture classes in university, and a previously-existing burning desire to understand emulation. I decided that the NES would be a good target; it was the oldest game hardware that I had personal interest in. In 2008, I found as much info as I could about how to structure an emulator, and technical documents about the NES, and started building. I got something basic working in a couple months, and came back to it every couple of years, either to add functionality or experiment with optimizations. > what are the basic concepts? A CPU goes through a repeating fetch->decode->execute loop, and mostly communicates with the rest of the system over a "bus", which has some number of address lines (in the NES, 16 address lines provide access to 2^16 or 65,536 addresses), some number of data lines (in the NES, 8 lines for 8-bit values), and some number of control lines (read/write, ready, and others that vary system-to-system). Different devices are connected at different address ranges. They could be RAM, ROM, I/O hardware, etc. So when a CPU is booting, the system is usually designed to expose some ROM at the first address the CPU fetches from. > what is the easiest hello-world game to start w/? Chip-8, probably. Space Invaders is a good one too; simple, but using a CPU related to those in a lot of other systems, and a bit less of a toy-scale system than Chip-8.

zeta0134 3y ago

The typical hello world is actually a CHIP 8 emulator, which is a type of VM that ran on an old calculator, the specifics of which elude me. It's got a tiny memory space, simple instructions and a handful of features, so it's the sort of thing you can get up and "running" with minimal effort. It lets you explore the high level concepts involved in running a "guest" system on some hosts, and tickles the challenge of synchronizing the timing and dealing with video and sound, without being overwhelming the way a physical console can be.

tester756 3y ago
Calculator sounds like a great idea! thanks
- khedoros1 3y ago
  "Calculator" doesn't quite cover it. CHIP-8 was developed to run on the COSMAC VIP home computer, and later similar ones like the Telmac 1800, which were shipped as kits for users to build at home.

khedoros1 3y ago

> how people start with game emulators? I had some Computer Organization and Architecture classes in university, and a previously-existing burning desire to understand emulation. I decided that the NES would be a good target; it was the oldest game hardware that I had personal interest in. In 2008, I found as much info as I could about how to structure an emulator, and technical documents about the NES, and started building. I got something basic working in a couple months, and came back to it every couple of years, either to add functionality or experiment with optimizations. > what are the basic concepts? A CPU goes through a repeating fetch->decode->execute loop, and mostly communicates with the rest of the system over a "bus", which has some number of address lines (in the NES, 16 address lines provide access to 2^16 or 65,536 addresses), some number of data lines (in the NES, 8 lines for 8-bit values), and some number of control lines (read/write, ready, and others that vary system-to-system). Different devices are connected at different address ranges. They could be RAM, ROM, I/O hardware, etc. So when a CPU is booting, the system is usually designed to expose some ROM at the first address the CPU fetches from. > what is the easiest hello-world game to start w/? Chip-8, probably. Space Invaders is a good one too; simple, but using a CPU related to those in a lot of other systems, and a bit less of a toy-scale system than Chip-8.