Multi-target assembler supporting Z80, 8080/8085, and 8086 instruction sets. Produces relocatable object files (.obj) for linking with hclink. Syntax is inspired by NASM with platform-specific extensions.

Usage

hcasm-{target} [options] <input.s>

Options:
  -o <file>       Output object file (default: a.obj)
  -dump <file>    Generate assembly listing dump
  -h              Show help

Source Format

label: mnemonic arg1, arg2 ; comment

• Labels: end with :, must start at column 1 (no leading whitespace)
• Instructions: must be indented with a tab or spaces
• Comments: start with ; and run to end of line
• Case-insensitive: all mnemonics, registers, and directives

Labels

global _start       ; export symbol for linker
extern printf       ; import symbol from another module

_start:             ; global label
.loop:              ; sub-label (becomes _start.loop)
    jp .loop        ; references _start.loop

Sections

section text        ; executable code
section data        ; initialized data (db, dw, dd)
section bss         ; uninitialized data (ds, rb, resb, rw, resw)

Output order: text → data → bss. BSS is zero-filled at load time.

Data Directives

Expressions and Number Formats

Operators: + - * / % — $ = current position — </LOBYTE — >/HIBYTE

Z80 — Syntax and Examples

; Z80 CP/M "Hello World"
section text
global _start
_start:
    ld de, msg
    ld c, 9             ; BDOS print string
    call 5
    ld c, 0             ; BDOS exit
    call 5

section data
msg: db "Hello, World!$"

8080/8085 — Syntax and Examples

; 8080 CP/M "Hello World"
section text
global _start
_start:
    lxi d, msg
    mvi c, 9
    call 5
    mvi c, 0
    call 5

section data
msg: db "Hello, World!$"

8086 — Syntax and Examples

; 8086 MS-DOS "Hello World"
section text
global _start
_start:
    mov ah, 9
    mov dx, msg
    int 0x21
    mov ah, 0x4C
    int 0x21

section data
msg: db "Hello, World!$"

Target Comparison