1 files changed, 82 insertions, 0 deletions
diff --git a/reference/C/CONTRIB/SNIP/iswprot.c b/reference/C/CONTRIB/SNIP/iswprot.c
new file mode 100755
index 0000000..3d2fb6b
--- /dev/null
+++ b/reference/C/CONTRIB/SNIP/iswprot.c
@@ -0,0 +1,82 @@
+/*
+**  ISWPROT.C - Detect if floppy drive is write protected
+**
+**  public domain by Bob Stout w/ corrections & additions by Wayne King
+*/
+
+#include <dos.h>
+
+#ifdef __TURBOC__
+ #define FAR far
+#else
+ #define FAR _far
+#endif
+
+/*
+**  isWprot()
+**
+**  Parameters: 1 - Drive number (A: = 0, B: = 1)
+**
+**  Returns: -1 - Error
+**            0 - Not write protected
+**            1 write protected
+**
+**  Note: If drive door is open, an error is returned but the critical
+**        error handler is NOT tripped
+*/
+
+int isWprot(int drive)
+{
+      union REGS regs;
+      struct SREGS sregs;
+      char buf[512], FAR *bufptr = (char FAR *)buf;   /* Needed by MSC  */
+
+      /* First read sector 0  */
+
+      segread(&sregs);
+      regs.x.ax = 0x201;
+      regs.x.cx = 1;
+      regs.x.dx = drive & 0x7f;
+      sregs.es  = FP_SEG(bufptr);
+      regs.x.bx = FP_OFF(bufptr);
+      int86x(0x13, &regs, &regs, &sregs);
+      if (regs.x.cflag && regs.h.ah != 6)
+      {
+            regs.h.ah = 0x00;         /* reset diskette subsystem */
+            regs.h.dl = drive & 0x7f;
+            int86x(0x13, &regs, &regs, &sregs);
+            return -1;
+      }
+
+      /* Try to write it back */
+
+      segread(&sregs);
+      regs.x.ax = 0x301;
+      regs.x.cx = 1;
+      regs.x.dx = drive & 0x7f;
+      sregs.es  = FP_SEG(bufptr);
+      regs.x.bx = FP_OFF(bufptr);
+      int86x(0x13, &regs, &regs, &sregs);
+      return (3 == regs.h.ah);
+}
+
+#ifdef TEST
+
+#include <stdio.h>
+#include <ctype.h>
+
+int main(int argc, char *argv[])
+{
+      int drive;
+
+      if (2 > argc)
+      {
+            puts("Usage: ISWPROT drive_letter");
+            return -1;
+      }
+      drive = toupper(argv[1][0]) - 'A';
+      printf("isWprot(%c:) returned %d\n", drive + 'A', isWprot(drive));
+      return 0;
+}
+
+#endif