New InstallShield script format?

AFAIR "isdcc" supports scripts for IS v5.5 and below (setup.ins). "sid" and "isd" supports v6+, but starting from v8 additional mangling is applied to the setup.inx. Try de-mangle it with the following code:

#include <stdio.h>
#include <fcntl.h>
#include <io.h>
#define XOR_VAL 0xF1
void main (void) {
int i, c;
unsigned char b;
// Set "stdin" and "stdout" to have binary mode
_setmode (_fileno (stdin), _O_BINARY);
_setmode (_fileno (stdout), _O_BINARY);
// Decrypt INX
for (i = 0; (c = getchar ()) != EOF; i++) {
c ^= XOR_VAL;
b = (unsigned char)((c >> 2) | (c << 6)) - (i % 71);
putchar (b);
}
}

and feed result to sid/isd