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23 lines
518 B
ArmAsm
23 lines
518 B
ArmAsm
* write one char to the crt
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* call with: ascii char to write in D0
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status1: .equ $3ff01 //really $3ff01
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port1: .equ $3ff03 //really $3ff03
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.globl _putchar
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.text
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_putchar:
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move.l (sp)+,A1 //return address
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move (sp),R0 //char to send
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move #1,R1
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move.l #status1,A0
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loop1: btst R1,(A0) //test transmitter empty
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beq loop1 //not empty
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move.b R0,2(A0) //send char
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cmp.b #$0a,R0 //line feed?
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bne l0
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move.b #$0d,R0 //carriage return
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bra loop1
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l0:
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jmp (A1) //return
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.end
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