diff --git a/hw/fdc.c b/hw/fdc.c
index e47a1da..cd00420 100644
--- a/hw/fdc.c
+++ b/hw/fdc.c
@@ -1137,9 +1137,9 @@
     } else {
         int tmp;
         fdctrl->data_len = 128 << (fdctrl->fifo[5] > 7 ? 7 : fdctrl->fifo[5]);
-        tmp = (cur_drv->last_sect - ks + 1);
+        tmp = (fdctrl->fifo[6] - ks + 1);
         if (fdctrl->fifo[0] & 0x80)
-            tmp += cur_drv->last_sect;
+            tmp += fdctrl->fifo[6];
         fdctrl->data_len *= tmp;
     }
     fdctrl->eot = fdctrl->fifo[6];