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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
/*
* Clock support for MPX-OS
* Ben Burwell & Averill Morash
* CSI350 - Fall 2013
*/
#include <dos.h>
#include "mpx.h"
void interrupt (*vect08)();
unsigned long clock; /* The clock counter */
/*
* Set up MXP clock
*/
void clock_open() {
unsigned char imr;
disable();
/* set up interrupt vector for timer interrupts */
vect08 = getvect(0x08);
setvect(0x08,&clock_int);
// set the timer mode
outportb(CMR, 0x36);
outportb(0x40, 0);
outportb(0x40, 0);
// set the count clock
clock = 0L;
// enable timer interrupts
imr = inportb(IMR); // Get current IMR
imr = imr & CLOCK_ENABLE; // Clear timer bit
outportb(IMR, imr); // Set new IMR
enable();
}
/*
* Restore the MS DOS clock
*/
void clock_close() {
disable();
setvect(0x08,vect08);
enable();
}
void interrupt clock_int() {
disable();
// if it's been 24 hours, reset clock to 0
if (clock >= 1572462L) {
clock = 0L;
} else {
clock++;
}
outportb(0x20, 0x20);
enable();
}
void stop_clock() {
unsigned char imr;
disable();
imr = inportb(IMR); // Get the old imr
imr = imr | CLOCK_DISABLE; // Disable timer interrupts
outportb(IMR, imr); // Set the new imr
enable();
}
/*
* Enables the timer interrupt
*/
void start_clock() {
unsigned char imr;
disable();
imr = inportb(IMR); // Get the old imr
imr = imr & CLOCK_ENABLE; // Enable timer interrupts
outportb(IMR, imr); // Set the new imr
enable();
}
/*
* Sets the value of the clock
*/
int set_clock(int hr, int m, int s) {
unsigned long ticks;
// Validate input
if (hr > 23 || hr < 0 || m > 59 || m < 0 || s > 59 || s < 0) {
return -1;
}
// set clock
ticks = 0L;
ticks = ((unsigned long)hr * 3600L * 91L / 5L);
ticks += ((unsigned long)m * 60L * 91L / 5L);
ticks += ((unsigned long)s * 91L / 5L);
disable();
clock = ticks;
enable();
return 0;
}
/*
* Gets the value of the clock
*/
void read_clock(int *hr, int *m, int *s) {
unsigned long ticks;
long total_seconds = 0L;
int l_hr = 0;
int l_m = 0; //local vars for hr, m
disable();
ticks = clock;
enable();
total_seconds = ticks * 10L;
total_seconds = total_seconds / 182L;
//count the whole hours
while (total_seconds >= 3600L) {
l_hr++;
total_seconds = total_seconds - 3600L;
}
//count the whole minutes
while (total_seconds >= 60L) {
l_m++;
total_seconds = total_seconds - 60L;
}
*hr = l_hr;
*m = l_m;
*s = total_seconds;
}
|
