IBM 5150 Hardware Reference Manual page 235

LOC (lBJ
LINE SOURCE
3007
j - - -
INT 17 --------------------------------­
3006 ; PRIfHER_IO
3009 TliIS ROUTINE PROVIDES COMMUNICATION WITH THE PRINTER
3010
(AH)=O F'RIHT THE CHARACTER IN (All
3011 ON RETUIHI, AH=1 IF CHARACTER COULD NOT BE PRINTED (TIME OUT)
3012
OTHER BITS SET AS
ON
NORMAL STATUS CALL
3013 (AH)=1 INITIALIZE THE PRunER PORT
3014
RETURNS WITH (AH) SET WITH PRINTER STATUS
3015 (AH)=2 READ THE PRINTER STATUS INTO UH)
3016
3017
TIME OUT
3018
51
i
t
1. ,::1
~~~~:D
3019
3020
_ 1 ::. SElECTED
3021
1 '"
OUT OF PAPER
3022
1 = ACKNOWLEDGE
'3023
1
= BUSY
3024
3025 (OX)
=
PRINTER TO BE USED (0.1.2) CORRESPONDING TO ACTUAL VALUES
3026
I IN PRINTER_BASE AREA
3027
; DATA AREA PRINTER_BASE CONTAItIS THE BASE ADDRESS OF THE PRINTER CAROlS)
3028 AVAILABLE (LOCATED AT BEGINNWG OF DATA SEGMENT, 408H ABSOLUTE, 3 WORDS)
3029
;REGISTER5 AH IS MODIfIED
3030 • ALL OTHERS UNCHANGED
3031
;
----
------ --
-------------------------------­
3032 ASSUME CS: CODE ,DS:DATA
EF02
3033 PRINTER _10 PROC fAR
EFOZ Fe 3034 STI
INTERRUPTS BACK ON
EF03 IE
3035 PUSH
os
j
SAVE SEGMENT
EFD4 52 3036 PUSH OX
EFOS 56
3037
PUSH
5'
EF06 51
3038 PUSH CX
HD7 53 3039 PUSH
ex
EFDB 8E4000 3040 NOV 51 ,DATA
EFDB BEDE 3041 NOV DS,SI ; ESTABLISH PRINTER SEGMENT
£FDD BaFl
3042-
HOV SI,DX ; GET PRINTER PARM
EFOF 01E6 3043
5HL 51,1 ; WORD OFFSET INTO TABLE
EFEl 88940800 3044 HOV OX,PRINTER_BASE[SI) ; GET BASE ADDRESS FOR PRINTER CARD
EFES 0802
3045 OR OX,OX
j
TEST OX FOR ZERO, INDICATING NO PRINTER
EFE7 740C 3046
JZ
Bl
j
RETURN
EFE9
0.6.£4
3047 OR AH,AH
TEST FOR {AH )=0
EFEB 740£ 3048
JZ
e.
PRINT_AL
£FED FEee 3049 DEC AH TEST FOR CAH)=1
.B
EFEF 7442
3050
JZ INIT_PRT
EFFl FEee 3051 DEC AH TEST FOR (AH
)::.2
EFF3 742.6. 3052- JZ 6S PR INTER STATUS
£FFS 3053 Bl : RETURN
EFF5 58 3054
POP
ex
EFF6 S9 3055 POP
ex
EfF7 5£ 3056 POP
j
RECOVER REGISTERS
5'
EFFS 5A 3057 POP
ox
j
RECOVER REGISTERS
EFF9 IF 3058 POP
Os
EFFA CF
3059
IRET
3060
3061
j------
PRINT THE CHARACTER IN (ALI
3062­
EFF6 3063
82:
EFFB 50
3064 PUSH AX SAVE VALUe TO PRINT
EFfC 830A 3065 HOV st.IO TIME OUT VALUE
EFFE 33C9 3066 XOR ex,Cx
ESTABLISH SHIFT COUNT
FOOD EE 3067 OUT DX,AL
; OUTPUT CHAR TO PORT
FOOl 42
3068
we ox ; PorNT
TO STATUS PORT
FOOl 3069 83: ; WAIT_BUSY
FOOZ EC 3070 AL,DX ; GET STATUS '"
F003 8AEO
3071
r.OV AH,AL
j
STATUS TO AH ALSO
Foes A880 3072 TEST At,SOH
; IS TtfE PRINTER CURRENTLY BUSY
F007 750E
3073 Jt~Z 6.
j
OUT_STrlOBE
F009 EZF] 3074 LOOP 63
; DECREMENT COUNT ON TIME OUT
FODe FEee
3075 DEC 6L
FOOD 75F3 3076 JHZ
63 ; WAIT FOR NOT BUSY
FOOF BOCCOI
3077
OR AH,l ; SET EPROR FLAG
FOl2 80E4F9 3078
Arm
AH,OF9H ; TURN OFF THE OTHER BITS
Fots EBI4 3079 JHP 5HORT 87 ; RETUPtl WITli ERROR flAG SET
FOl7
30BO
84: ; OUT_STReBE
FOl7 BOOO 3081 HOV AL,OOH
j
SET THE STROBE HIGH
F019 42 3082
we
DX
; STROBE IS BIT 0 OF PORT C OF 8255
A-42