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78 lines
1.1 KiB
NASM
78 lines
1.1 KiB
NASM
; stdio
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;
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; Allows other modules to print to "standard out", that is, the console through
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; which the user is connected in a decoupled manner.
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;
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; *** REQUIREMENTS ***
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; STDIO_GETC: a macro that follows GetC API
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; STDIO_PUTC: a macro that follows GetC API
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; *** VARIABLES ***
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; Used to store formatted hex values just before printing it.
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STDIO_HEX_FMT .equ STDIO_RAMSTART
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STDIO_RAMEND .equ STDIO_HEX_FMT+2
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; print null-terminated string pointed to by HL
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printstr:
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push af
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push hl
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.loop:
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ld a, (hl) ; load character to send
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or a ; is it zero?
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jr z, .end ; if yes, we're finished
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STDIO_PUTC
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inc hl
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jr .loop
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.end:
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pop hl
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pop af
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ret
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; print A characters from string that HL points to
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printnstr:
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push bc
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push hl
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ld b, a
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.loop:
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ld a, (hl) ; load character to send
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STDIO_PUTC
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inc hl
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djnz .loop
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.end:
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pop hl
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pop bc
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ret
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printcrlf:
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ld a, ASCII_CR
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STDIO_PUTC
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ld a, ASCII_LF
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STDIO_PUTC
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ret
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; Print the hex char in A
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printHex:
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push af
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push hl
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ld hl, STDIO_HEX_FMT
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call fmtHexPair
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ld a, 2
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call printnstr
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pop hl
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pop af
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ret
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; Print the hex pair in HL
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printHexPair:
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push af
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ld a, h
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call printHex
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ld a, l
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call printHex
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pop af
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ret
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