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https://github.com/visrealm/vremutms9918
TMS9918A emulator library (C99)
https://github.com/visrealm/vremutms9918
assembly c colecovision creativision emulator graphics hardware msx sprites ti-99 ti99 tms9918 tms9918-emulation tms9918a tms9928 tms9929a video
Last synced: 5 days ago
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TMS9918A emulator library (C99)
- Host: GitHub
- URL: https://github.com/visrealm/vremutms9918
- Owner: visrealm
- License: mit
- Created: 2021-09-03T07:28:19.000Z (about 3 years ago)
- Default Branch: main
- Last Pushed: 2024-05-22T02:11:58.000Z (6 months ago)
- Last Synced: 2024-05-23T02:44:34.673Z (6 months ago)
- Topics: assembly, c, colecovision, creativision, emulator, graphics, hardware, msx, sprites, ti-99, ti99, tms9918, tms9918-emulation, tms9918a, tms9928, tms9929a, video
- Language: C
- Homepage:
- Size: 3.2 MB
- Stars: 40
- Watchers: 3
- Forks: 8
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# vrEmuTms9918 - TMS9918 / TMS9918A / TMS9929A VDP Emulator
TMS9918 emulator. Core engine written in C99. Zero dependencies.
The goal is to emulate all documented modes listed in the [TMS9918A/TMS9928A/TMS9929A datasheet](http://www1.cs.columbia.edu/~sedwards/papers/TMS9918.pdf)
## Supported Modes
* Graphics I (including sprites)
* Graphics II (including sprites)
* Multicolor mode (including sprites)
* Text
## Other features
* 5th sprite
* Sprite collisions
* VSYNC interrupt
* Individual scanline rendering
## PICO9918
This library is also being used in the PICO9918 project. A drop-in replacement for a physical TMS9918A powered by a Raspberry Pi Pico.
The PICO9918 running in an original TI-99/4A:
### Don't mess with Texas!
[](https://youtu.be/ljNRFKbOGJs)
See [github.com/visrealm/pico9918](https://github.com/visrealm/pico9918)
## Demos:
#### Graphics Mode I Demo
#### Graphics Mode II Demo
#### Text Mode Demo
#### Multicolor Mode Demo
## Building
vrEmuTms9918 uses the CMake build system
#### Checkout repository
```
git clone https://github.com/visrealm/vrEmuTms9918.git
cd vrEmuTms9918
```
#### Setup build
```
mkdir build
cd build
cmake ..
```
#### Build
```
cmake --build .
```
Windows: Optionally, open the generated solution file
#### Run tests
```
ctest
```
Windows: Optionally, build the ALL_TESTS project in the generated solution file
## Quick start
```c
#include "vrEmuTms9918.h"
#include "vrEmuTms9918Util.h"
#define TMS_VRAM_NAME_ADDRESS 0x3800
#define TMS_VRAM_COLOR_ADDRESS 0x0000
#define TMS_VRAM_PATT_ADDRESS 0x2000
#define TMS_VRAM_SPRITE_ATTR_ADDRESS 0x3B00
#define TMS_VRAM_SPRITE_PATT_ADDRESS 0x1800
// program entry point
int main()
{
// create a new tms9918
VrEmuTms9918 *tms9918 = vrEmuTms9918New();
// Here, we're using the helper functions provided by vrEmuTms9918Util.h
//
// In a full system emulator, the only functions required (connected to the system bus) would be:
//
// * vrEmuTms9918WriteAddr()
// * vrEmuTms9918WriteData()
// * vrEmuTms9918ReadStatus()
// * vrEmuTms9918ReadData()
//
// The helper functions below wrap the above functions and are not required.
// vrEmuTms9918Util.h/c can be omitted if you're not using them.
//
// For a full example, see https://github.com/visrealm/hbc-56/blob/master/emulator/src/devices/tms9918_device.c
// set up the VDP write-only registers
vrEmuTms9918WriteRegisterValue(tms9918, TMS_REG_0, TMS_R0_MODE_GRAPHICS_I);
vrEmuTms9918WriteRegisterValue(tms9918, TMS_REG_1, TMS_R1_MODE_GRAPHICS_I | TMS_R1_RAM_16K);
vrEmuTms9918SetNameTableAddr(tms9918, TMS_VRAM_NAME_ADDRESS);
vrEmuTms9918SetColorTableAddr(tms9918, TMS_VRAM_COLOR_ADDRESS);
vrEmuTms9918SetPatternTableAddr(tms9918, TMS_VRAM_PATT_ADDRESS);
vrEmuTms9918SetSpriteAttrTableAddr(tms9918, TMS_VRAM_SPRITE_ATTR_ADDRESS);
vrEmuTms9918SetSpritePattTableAddr(tms9918, TMS_VRAM_SPRITE_PATT_ADDRESS);
vrEmuTms9918SetFgBgColor(tms9918, TMS_BLACK, TMS_CYAN);
// send it some data (a pattern)
vrEmuTms9918SetAddressWrite(tms9918, TMS_VRAM_PATT_ADDRESS);
// update pattern #0
char smile[] = {0b00111100,
0b01000010,
0b10000001,
0b10100101,
0b10000001,
0b10011001,
0b01000010,
0b00111100};
vrEmuTms9918WriteBytes(tms9918, smile, sizeof(smile));
// update fg/bg color for first 8 characters
vrEmuTms9918SetAddressWrite(tms9918, TMS_VRAM_COLOR_ADDRESS)
vrEmuTms9918WriteData(tms9918, vrEmuTms9918FgBgColor(TMS_BLACK, TMS_LT_YELLOW));
// output smile pattern to screen
vrEmuTms9918SetAddressWrite(tms9918, TMS_VRAM_NAME_ADDRESS);
// a few smiles
vrEmuTms9918WriteData(tms9918, 0x00);
vrEmuTms9918WriteData(tms9918, 0x00);
vrEmuTms9918WriteData(tms9918, 0x00);
// render the display
char scanline[TMS9918A_PIXELS_X]; // scanline buffer
// an example output (a framebuffer for an SDL texture)
uint32_t frameBuffer[TMS9918A_PIXELS_X * TMS9918A_PIXELS_Y];
// generate all scanlines and render to framebuffer
uint32_t *pixPtr = frameBuffer;
for (int y = 0; y < TMS9918A_PIXELS_Y; ++y)
{
// get the scanline pixels
vrEmuTms9918ScanLine(tms9918, y, scanline);
for (int x = 0; x < TMS9918A_PIXELS_X; ++x)
{
// values returned from vrEmuTms9918ScanLine() are palette indexes
// use the vrEmuTms9918Palette array to convert to an RGBA value
*pixPtr++ = vrEmuTms9918Palette[scanline[x]];
}
}
// output the buffer...
...
// clean up
vrEmuTms9918Destroy(tms9918);
tms9918 = NULL;
return 0;
}
```
## Real example
This library is used in the [HBC-56](https://github.com/visrealm/hbc-56) emulator.
The HBC-56 uses this library to support:
* Rendering to an SDL texture.
* TMS9918 VSYNC Interrupts.
* Time-based rendering. Supports beam-time.
Full source: [hbc-56/emulator/src/devices/tms9918_device.c](https://github.com/visrealm/hbc-56/blob/master/emulator/src/devices/tms9918_device.c)
## License
This code is licensed under the [MIT](https://opensource.org/licenses/MIT "MIT") license