https://github.com/maokij/ocala
Ocala is an assembler for Z80 / R800 / 6502.
https://github.com/maokij/ocala
6502 assembler msx r800 z80
Last synced: 2 months ago
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Ocala is an assembler for Z80 / R800 / 6502.
- Host: GitHub
- URL: https://github.com/maokij/ocala
- Owner: maokij
- License: mit
- Created: 2025-05-17T06:00:32.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2026-01-01T09:54:52.000Z (7 months ago)
- Last Synced: 2026-01-04T21:27:44.416Z (7 months ago)
- Topics: 6502, assembler, msx, r800, z80
- Language: Go
- Homepage: https://maokij.github.io/
- Size: 655 KB
- Stars: 2
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
- Notice: NOTICE.txt
Awesome Lists containing this project
README
# Ocala
Ocala is an assembler for Z80 / 6502.
https://maokij.github.io/
MSX1 sprite32:
MSX2 scroll:
## Features
- Modules and namespaces
- Flexible link methods
- Macros and inline procedures
- Controll flows like if/loop
- Infix notation for machine language instructions
- MSX BIOS functions library
## Example Code
Hello world for MSX:
```
// Specify the target CPU.
arch z80
// Include another file.
include "msx.oc"
// Specify the link method.
msx:link-as-rom main _
// Define the module.
module main {
// Define the procedure.
proc main() {
// Define message string data. This will be placed in the rodata section.
data message = byte [ "Hello, world!" ] : rodata
// Initialize the SP register. Same as "LD SP, F380h."
SP <- msx:STACK_ADDR
// Initialize the screen as 32x24 mode using BIOS.
msx:init32(!)
// Transfer data to the screen using BIOS.
BC@sizeof(message) . DE@msx:t32nam(10 12) . HL@message . msx:ldirvm(BC DE HL => !)
// The main loop. Do nothing.
never-return loop { msx:wait }
}
}
```
Output assembly list:
```
__ARCH__ = "z80"
- 4000 .org 16384
000000 4000[8] 41 42 10 40 00 00 00 00 .byte 65, 66, 16, 64, 0, 0, 0, 0
000008 4008[8] 00 00 00 00 00 00 00 00 .byte 0, 0, 0, 0, 0, 0, 0, 0
- 4010 main:main:
000010 4010[3] 31 80 f3 LD SP, msx:STACK_ADDR
000013 4013[3] cd 6f 00 CALL msx:init32
000016 4016[3] 01 0d 00 LD BC, sizeof(.message.#984)
000019 4019[3] 11 8a 19 LD DE, msx:t32nam(10 12)
00001c 401c[3] 21 26 40 LD HL, .message.#984
00001f 401f[3] cd 5c 00 CALL msx:ldirvm
- 4022 .beg.G1.#988:
000022 4022[1] 76 HALT
000023 4023[3] c3 22 40 JP .beg.G1.#988
- 4026 .align 2 ; (.defb 0)
- 4026 .message.#984:
000026 4026[8] 48 65 6c 6c 6f 2c 20 77 .byte "Hello, world!"
:[5] 6f 72 6c 64 21
- c000 .org 49152
```
## Installation
### Using precompiled binaries
Download the archive of latest version from
the [releases](https://github.com/maokij/ocala/releases) page.
Then extract all files from the archive.
To verify your installation, try below.
```
$ ./ocala/bin/ocala -h
```
And make a symbolic link to the binary file if necessary.
```
$ ln -nfs "$(realpath ./ocala/bin/ocala)" ~/.local/bin/ocala
```
### Building from source
Clone this repository. Then execute below.
```
$ make install prefix=$HOME/.local
```
## Usage
```
Usage: ocala [options] file
Options:
-D value
Define the symbol
-I value
Add the directory to the include path
-L string
Specify the list file name
-V Display the version information
-l Generate a list file
-o string
Specify the output file name
-t string
Specify the target arch
```
## License
MIT