D.1 busmon.c

/*****************************************************************
** B U S M O N . C
** Bus Monitor Hardware interface
** Reads 24-bit count of memory references each timer tick.
*/

#include <conio.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dos.h>
#ifdef GFX
#include <graphics.h>
#endif

#define MINUTES 8
#define BUFLEN (MINUTES*1092)
#define MAXTRIES 10

#define MC_CLEAR (IOport)
#define MC_READ0 (IOport)
#define MC_READ1 (IOport+1)
#define MC_READ2 (IOport+2)

void interrupt far watch_port(void);
void (interrupt far *old_timertick)(void);

volatile unsigned long MemCount[BUFLEN];
volatile int Debug[BUFLEN];
volatile int BufPtr = 0;
unsigned int IOport = 0x300;
char Command[80] = "COMMAND";

void main(int argc, char *argv[])
    {
    int i, ch, base;
    unsigned long clip = 687000L;  /* 12.5 MHz / 18.2 Hz */
    char fname[80];
    char *endptr;
    FILE *f;

    if (argc>1)
        IOport = (unsigned int)strtoul(argv[1], &endptr, 0);
    if (argc>2)
        strcpy(Command, argv[2]);

    old_timertick = _dos_getvect(0x1c);
    _dos_setvect(0x1c, watch_port);

    printf("MemCount Port (%x) hooked to timer tick interrupt.\n", IOport);
    printf("Space allocated for roughly %d minutes worth of data.\n", MINUTES);
    system(Command);
    _dos_setvect(0x1c, old_timertick);

    /* Throw out the first count. */
    printf("A total of %d MemCounts were read.\n", BufPtr-1);
    do {
        printf("(S)ave, (A)verage, Plot (V)GA or (T)ext, (C)lip, (Q)uit: ");
        ch = toupper(getch());
        if (ch=='S') {
            printf("\nEnter filename: ");
            scanf("%s", fname);
            f = fopen(fname, "wt");
            for (i=1; i<BufPtr; i++)
                fprintf(f, "%d %d %lu\n", i, Debug[i], MemCount[i]);
            fclose(f);
            }
        else if (ch=='A') {
            double sum = 0.0;
            for (i=1; i<BufPtr; i++)
                sum += MemCount[i];
            printf("\nAverage MemCount = %lf.\n", sum/(BufPtr-1));
            }
        else if (ch=='C') {
            printf("\nCurrent clip value %ld.  Enter new value: ", clip);
            scanf("%ld", &clip);
            }
#ifdef GFX
        else if (ch=='V') {
            int gd=VGA, gm=VGAHI;
            initgraph(&gd, &gm, "\\ borlandc\\ bgi");
            base = 1;
            while (base<BufPtr) {
                for (i=0; i<640; i++) {
                    if (i+base>=BufPtr)
                        break;
                    putpixel(i, 479-(int)((double)479*MemCount[i+base]/clip), WHITE);
                    }
                i = getch();
                if (i==27) break;
                base += 640;
                cleardevice();
                }
            closegraph();
            }
#endif
        else if (ch=='T') {
            clrscr();
            base = 1;
            while (base<BufPtr) {
                for (i=0; i<640; i++) {
                    if (i+base>=BufPtr)
                        break;
                    if (MemCount[i+base] < clip) {
                        gotoxy(1+(i/8), 25-(int)((double)25*MemCount[i+base]/clip));
                        putch('X');
                        }
                    }
                i = getch();
                if (i==27) break;
                base += 640;
                clrscr();
                }
            }
        }
    while (ch != 'Q');
    }


void interrupt far watch_port()
    {
    unsigned long c=0L;
    int i;

    if (BufPtr < BUFLEN) {
        ((unsigned char *)(&c))[0] = inportb(MC_READ0);
        ((unsigned char *)(&c))[1] = inportb(MC_READ1);
        ((unsigned char *)(&c))[2] = inportb(MC_READ2);
        for (i=0; i<MAXTRIES; i++) {
            outportb(MC_CLEAR, 0);      /* clear counters */
            if (inportb(MC_READ1)==0) { /* verify clear */
                Debug[BufPtr] = i+1;
                break;
                }
            }
        MemCount[BufPtr++] = c;
        }
    _chain_intr(old_timertick);
    }