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https://github.com/visrealm/hbc-56

Homebrew 65C02 computer on a backplane
https://github.com/visrealm/hbc-56

6502 6502-processor 8-bit assembly ay-3-8910 backplane c commodore emulation emulator homebrew pcb tms9918 z80

Last synced: 5 days ago
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Homebrew 65C02 computer on a backplane

Host: GitHub
URL: https://github.com/visrealm/hbc-56
Owner: visrealm
License: mit
Created: 2021-06-05T07:27:34.000Z (over 3 years ago)
Default Branch: main
Last Pushed: 2024-06-15T01:15:12.000Z (5 months ago)
Last Synced: 2024-10-25T22:31:53.605Z (11 days ago)
Topics: 6502, 6502-processor, 8-bit, assembly, ay-3-8910, backplane, c, commodore, emulation, emulator, homebrew, pcb, tms9918, z80
Language: Assembly
Homepage: https://youtube.com/@TroySchrapel
Size: 65.7 MB
Stars: 193
Watchers: 13
Forks: 27
Open Issues: 2
Metadata Files:
- Readme: README.md
- License: LICENSE

Awesome Lists containing this project

README

        # HBC-56







A homebrew 8-bit computer on a (56 pin) backplane.

Initially supporting the 65C02 CPU, TMS9918A VDP and Dual AY-3-8910 PSG's. With plans to add support for Z80 and perhaps other CPUs in the future.

Current cards:

* 65C02 CPU card with 65C22 VIA and Interrupt controller

* RAM/ROM card (32KB of each) + optional 32KB shadow RAM

* LCD display card (supports regular character LCD and 12864B graphics LCD)

* TMS9918A display card (composite output)

* Dual AY-3-8910 sound card

* PS/2 keyboard and dual NES controller card



All [source code](code/6502) and [schematics](schematics) are available in this repository.

## Emulator

I have also included an emulator for this system. The emulator supports the following:

* Realtime execution of code (at ~3.7MHz).

* Step through disassembled code with labels.

* Source code debugging (using ACME assembler .rpt file).

* TMS9918 VRAM visualisation of pattern and sprite pattern tables.

* Examine CPU and VDP registers, RAM and VRAM.

* Full support for all TMS9918A display modes. See my TMS9918 emulator here: [github.com/visrealm/vrEmuTms9918](https://github.com/visrealm/vrEmuTms9918)

* Support for the dual AY-3-8910 audio, keyboard and NES controller.

The emulator is also available for Web (Beta). [HBC-56 Emulator Online](https://visrealm.github.io/hbc-56/github-pages/emulator)



Full details on the Emulator and source code here: [emulator](emulator)

### PICO-56

The PICO-56 project emulates the entire HBC-56 system on a single Raspberry Pi Pico.



PICO-56 repository: [https://github.com/visrealm/pico-56](https://github.com/visrealm/pico-56)

## Building

This project uses the CMAKE build system to build the emulator and assembler. VSCode works very well with CMAKE, but you can also build manually:

### Windows or Linux

```

$ git clone --recurse-submodules https://github.com/visrealm/hbc-56.git

$ cd hbc-56

$ cmake -B build -DCMAKE_BUILD_TYPE=Release -S .

$ cmake --build build --config Release

```

The `hbc-56/build/bin` directory will then hold everything you need to run the emulator.

### WebAssembly

To build the WebAssembly version of the emulator (from `/hbc-56`): 

##### Windows (Developer Command Prompt)

```

$ ./emconfigure build_wasm

$ cmake --build build_wasm --config Release

```

##### Linux

```

$ ./emconfigure.sh build_wasm

$ cmake --build build_wasm --config Release

```

To test the WebAssembly build, you will need to serve the files from a web server. A simple python http.server will work just fine:

```

$ cd build_wasm/bin

$ python -m http.server

Serving HTTP on :: port 8000 (http://[::]:8000/) ...

```

Then navigate to [http://localhost:8000](http://localhost:8000)

## Running the demos

There are several ways to build and run the demos. They are set up with makefiles, so it is preferred to have [MAKE](http://gnuwin32.sourceforge.net/packages/make.htm) installed and in your PATH environment variable.

#### VSCode

1. Open the [code/6502](code/6502) directory in VSCode

2. For each test/demo program (eg. basic, invaders, tests\tms, tests\sfx, etc.) navigate to the .asm file and hit **\+\**. This will build and run the program in the emulator. **\+\+\** to just build the ROM image without running.

  

#### Command-line (MAKE)

  

For each path ([basic](code/6502/basic), [invaders](code/6502/invaders), [tests/tms](code/6502/tests/tms),[tests/sfx](code/6502/tests/sfx)):

1. Open a console to the path

2. Type `make` (this will build the default program and run it in the emulator:




 * Type `make all` to build and run all demos in the directory

 * Type `make ` (filename without extension) to build and run a specific demo eg:

 

```

cd code/6502/tests/inp

make kbtest

```



#### Manually building a demo (without MAKE)

Example: invaders

```

cd code\6502\invaders

..\..\..\tools\acme\acme -I ..\lib -I ..\kernel -o invaders.o -l invaders.o.lmap invaders.asm

```

#### Manually running a demo  (without MAKE)

Example: invaders

```

cd code\6502\invaders

..\..\..\emulator\bin\Hbc56Emu.exe --rom invaders.o

```



Example: basic

```

cd code\6502\basic

..\..\..\emulator\bin\Hbc56Emu.exe --rom basic_tms.o

```



## Memory map

The HBC-56 has 64KB addressable memory divided into RAM, ROM and IO as follows:

| From | To | Purpose |

|--|--|--|

| $0000 | $7eff | RAM |

| $7f00 | $7fff | I/O |

| $8000 | $ffff | ROM |

The RAM and ROM is further divided by the HBC-56 Kernel:

| From | To | Size | Purpose |

|--|--|--|--|

| $0000 | $00ff | 256 bytes | Zero page |

| $0100 | $01ff | 256 bytes | Stack |

| $0200 | $79ff | 30 kilobytes | User RAM |

| $7a00 | $7eff | 1280 bytes | Kernel RAM |

| $7f00 | $7fff | 256 bytes | I/O |

| $8000 | $dfff | 24 kilobytes | User ROM |

| $e000 | $ffff | 8 kilobytes | Kernel ROM |

IO ports for current devices (all at $7fxx)

| Port | Purpose |

|--|--|

| $02 | LCD Command |

| $03 | LCD Data |

| $08 | ROM Banking Register |

| $10 | TMS9918A Command |

| $11 | TMS9918A Data |

| $20 | UART MC68B50 Register |

| $21 | UART MC68B50 Data |

| $40 | AY-3-8910 A Register |

| $41 | AY-3-8910 A Write |

| $42 | AY-3-8910 A Read |

| $44 | AY-3-8910 B Register |

| $45 | AY-3-8910 B Write |

| $46 | AY-3-8910 B Read |

| $80 | PS/2 Keyboard Data |

| $81 | PS/2 Keyboard Status |

| $82 | NES 1 Data |

| $83 | NES 2 Data |

| $df | Interrupt Register |

| $f0 - $ff | 65c22 VIA |

### Thanks

Thanks to PCBWay for supporting this project.

[![PCBWay](/img/pcbway_sm.png)](https://pcbway.com/g/186WQ9)

## Videos

[![Backplane 6502 + TMS9918: Breakout](https://img.visualrealmsoftware.com/youtube/thumb/4C_1yekWGg4)](https://www.youtube.com/watch?v=4C_1yekWGg4 "Backplane 6502 + TMS9918: Breakout")

[![Backplane 6502 + TMS9918: Invaders](https://img.visualrealmsoftware.com/youtube/thumb/Ug6Ppz-NF2Q)](https://www.youtube.com/watch?v=Ug6Ppz-NF2Q "Backplane 6502 + TMS9918: Invaders")

[![6502 8-bit homebrew with backplane. Troy's HBC-56 project preview.](https://img.visualrealmsoftware.com/youtube/thumb/x4IN8i7_U_4?t=3)](https://www.youtube.com/watch?v=x4IN8i7_U_4 "6502 8-bit homebrew with backplane. Troy's HBC-56 project preview.")

## License

This code is licensed under the [MIT](https://opensource.org/licenses/MIT "MIT") license