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Fix labels and improve comments

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Jeremiah Orians 2017-12-16 16:40:26 -05:00
parent 0e23b418ae
commit c67bbc8fff
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1 changed files with 12 additions and 3 deletions
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15
stage0/stage0_monitor.s
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@ -44,22 +44,31 @@
;; Check for EOF
JUMP.NP R0 @finish
:.L1
;; Write out unprocessed byte
LOADUI R1 0x1101 ; Write to TAPE_02
FPUTC ; Print the Char
;; Convert byte to nybble
CALLI R13 @hex ; Convert it
;; Get another byte if nonhex
JUMP.NP R0 @loop ; Don't use nonhex chars
JUMP.Z R11 @.L99 ; Jump if toggled
;; Deal with the case of second nybble
JUMP.Z R11 @second_nybble ; Jump if toggled
;; Process first byte of pair
ANDI R15 R0 0x0F ; Store First nibble
FALSE R11 ; Flip the toggle
JUMP @loop
:.L99
;; Combined second nybble in pair with first
:second_nybble
SL0I R15 4 ; Shift our first nibble
ANDI R0 R0 0x0F ; Mask out top
ADD R0 R0 R15 ; Combine nibbles
;; Writeout and prepare for next cycle
LOADI R11 1 ; Flip the toggle
LOADUI R1 0x1100 ; Write the combined byte
FPUTC ; To TAPE_01