1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
;
page 60,132
;
title CP/DOS VioWrtCharStrAtt mapper
;
vioxxx segment byte public 'vio'
assume cs:vioxxx,ds:nothing,es:nothing,ss:nothing
;
; ************************************************************************* *
; *
; * MODULE: viowrtcharstratt Write character string with attribute
; *
; * FILE NAME: wchstra.asm
; *
; * CALLING SEQUENCE:
; *
; * push@ dword char_str
; * push word length
; * push word row
; * push word column
; * push@ dword attribute
; * push word vio handle
; * call viowrtcharstr
; *
; *
; * MODULES CALLED: BIOS int 10h
; *
; *************************************************************************
public viowrtcharstratt
.sall
.xlist
include macros.inc
.list
full_scr_err equ 0001h
error_bvs_parameter equ 0002h
str struc
old_bp dw ?
return dd ?
handle dw ? ; vio handle
attr dd ? ; attribute pointer
column dw ? ; column number
row dw ? ; starting position for output
lngth dw ? ; length of the string
addr dd ? ; string to be written (pointer)
str ends
viowrtcharstratt proc far
Enter viowrtcharstratt ; push registers
sub bh,bh
sub ax,ax ; Start with clean error condition
mov dx,[bp].column ; get column number
cmp dl,80 ; check for upper boundry
jg error ; branch if illegal number
mov ax,[bp].row ; get row number
cmp al,25 ; check for upper boundry
jg error ; branch if illegal number
mov dh,al
mov ah,02h
pushal ; Save registers in case int 10h
; messes them up
int 10h ; Set start cursor position
popal
lds si,[bp].attr ; Set up attribute in BL
mov bl,byte ptr ds:[si]
lds si,[bp].addr ; DS:SI is pointer to string
mov di,[bp].lngth
; ****************************
; cmp bl,15 ; ** assume good attribute! **
; jg error ; ****************************
top: mov al,byte ptr [si]
mov ah,09h ; set write char/attrib function code
mov cx,1 ; write only one character
pushal ; Save registers in case int 10h
; messes them up
int 10h ; Output one character
popal ; restore registers
inc si
dec di
inc dl
cmp dl,80 ; Handle end of line condition
jne around ; |
inc dh ; |
mov dl,00 ; V
cmp dh,25 ; Handle end of screen condition
jne around ; |
mov ax,full_scr_err ; Error in AX
jmp exit
around: mov ah,02h
pushal ; Save registers in case int 10h
; messes them up
int 10h ; Increment cursor position
popal
cmp di,0 ; check if complete string is written
jne top ; else, go and write next character
sub ax,ax ; set no error code
error: mov ax,error_bvs_parameter
exit: Mexit ; return
ret size str - 6
;
viowrtcharstratt endp
vioxxx ends
end
|
