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57 lines
2.1 KiB
NASM
57 lines
2.1 KiB
NASM
1 year ago
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; echo example - takes input and then prints it back out
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; This is for testing the InputConsole of the Simple Test Machine
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; by Joey Pollack
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; assemble with win2c64 (or lin2c64, or mac2c64) using the -R option
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; win2c64 found here:
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; https://www.aartbik.com/retro.php
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; CONSTANTS
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con_out .equ $1100 ; console output buffer address
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con_in .equ $1200 ; console input buffer address
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con_flags .equ $009A ; console flags address
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prt_str_flag .equ $0002 ; print string flag
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prmp_input_flag .equ $0004 ; prompt for input flag
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; MAIN
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main .org $0200 ; program load address for the Simple Test Machine
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ldx #0
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loop lda text,x
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sta con_out,x
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inx
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cpx #12 ; length of text
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bne loop
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; null terminate the string
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lda #0
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sta con_out,x
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; Print the prompt message
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lda con_flags ; load the console flags
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ora #prt_str_flag ; set the print string flag
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sta con_flags ; store the modified flags
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; Prompt the user for input
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lda con_flags ; load the console flags
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ora #prmp_input_flag ; set the prompt for input flag
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sta con_flags ; store the flags back to memory - this should trigger reading input
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; Echo the input back to the console
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; iterate the input buffer and move each byte to the output buffer
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ldx #0 ; initialize the offset counter
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loop2 lda con_in,x ; load byte from the input buffer, offset by x register
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sta con_out,x ; store byte into output buffer, offset by x register
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inx ; increment the offset
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cmp #0 ; check for the null byte
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bne loop2 ; branch back to loop2 if we are not at the null byte yet
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lda con_flags ; load the console flags
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ora #prt_str_flag ; set the print string flag
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sta con_flags ; store the modified flags
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; End the program
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rts ; 0x60
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; MEMORY
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text .byte "Enter Text: "
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