IBM PC CONVERTIBLE Technical Reference page 228

Convert AX to ASCII (DSP _BYTE)
06C6
06C6 51
06C7
50
06C8 B1 04
06CA 02 E8
06CC E8 06EO R
06CF E8 06E7 R
0602 8A E8
0604 58
0605 24 OF
0607 E8 06EO R
06DA 8A E5
06DC 59
0600 EB 08 90
06EO
06EO
06EO 04 90
06E2 27
06E3 14 40
06E5 27
06E6 C3
06E7
06E7
06E7 50
06E8 53
06E9 B4 DE
06EB B7 00
06ED CD 10
06EF 5B
06FO 58
06Fl C3
06F2
*********************************************************************
ROUTINE-NAME: DSP _BYTE
FUNCTION: THIS ROUTINE Will CONVERT THE BYTE
IN
Al INTO TWO ASCII
CHARACTERS
IN
AX AND DISPLAY THEM AT THE CURRENT
CURSOR lOCATION. THE CURSOR Will BE MOVED TWO CHARACTERS
TO THE RIGHT.
ENTRY CONDITIONS:
INPUT CONDITIONS: DSP_BYTE: Al
XlALNIB: Al
DSP_HEX: Al
RESTRICTIONS: NONE
EXIT CONDITIONS:
BYTE TO BE CONVERTED
lOW NI BBlE TO BE CONVERTED
BYTE TO BE DISPLAYED
DSP_BYTE: BYTE IS CONVERTED AND PRINTED, ASCII IN AX
XlALNIB: ASCII RETURNED IN Al
DSP_HEX: CHARACTER DISPLAYED AND CURSOR ADVANCED
REGISTERS MODIFIED: AX
*********************************************************************
DSP _BYTE PROC NEAR
PUSH CX
PUSH
AX
SAVE FOR lOW NIBBLE DISPLAY
MOV Cl,4 SHI FT COUNT
SHR
Al,Cl
NYBBlE SWAP
CAll XlALNIB CONVERT THE HIGH NI BBlE
CAll DSP _HEX DISPLAY THE FIRST CHARACTER
MOV CH,Al SAVE UPPER ASCI I CHARACTER
POP AX RECOVER THE NIBBLE
AND Al,OFH ISOLATE TO lOW NIBBLE
DO lOW NIBBLE CONVERSION
CAll XlALNIB 2ND ASCII CHARACTER IN Al
MOV AH,CH RESTORE 1ST ASCI I CHAR TO AH
POP CX
JMP
DSP _HEX
DISPLAY SECOND CHARACTER
DSP _BYTE
ENDP
CONVERT BYTE IN lOW NIBBLE IN Al TO ASCII IN Al
XlALNIB PROC NEAR
ADD Al,090H ADD FIRST CONVERSION FACTOR
DAA ADJ FOR NUM AND ALPHA RANGE
ADC Al,040H ADD CONV AND ADJ lOW
NI
BBlE
DAA ADJ HIGH NIB TO ASCHI RANGE
RET
XlALNIB ENDP
PRINT CHARACTER IN Al USING TELETYPE INTERFACE TO VIDEO 1(0
DSP _HEX PROC NEAR
PUSH AX SAVE REGS
PUSH BX
MOV AH,14 DISPLAY CHARACTER IN Al
MOV BH,O
INT 10H
CAll VIDEO_IO
POP BX RESTORE REGS
POP AX
RET
DSP _HEX
ENDP
ROM BIOS 2-203