diff --git a/sortix/bga.cpp b/sortix/bga.cpp
index dac62a3d..f73c0e49 100644
--- a/sortix/bga.cpp
+++ b/sortix/bga.cpp
@@ -380,7 +380,7 @@ ssize_t BGADriver::WriteAt(off_t off, const void* buf, size_t count)
 	if ( (off_t) framesize <= off )
 		return 0;
 	if ( framesize < off + count )
-		count = off - framesize;
+		count = framesize - off;
 	Maxsi::Memory::Copy(frame + off, buf, count);
 	return count;
 }
@@ -391,7 +391,7 @@ ssize_t BGADriver::ReadAt(off_t off, void* buf, size_t count)
 	if ( (off_t) framesize <= off )
 		return 0;
 	if ( framesize < off + count )
-		count = off - framesize;
+		count = framesize - off;
 	Maxsi::Memory::Copy(buf, frame + off, count);
 	return count;
 }
diff --git a/sortix/video.cpp b/sortix/video.cpp
index 9245832c..2c44d01c 100644
--- a/sortix/video.cpp
+++ b/sortix/video.cpp
@@ -427,7 +427,7 @@ ssize_t ReadAt(off_t off, void* buf, size_t count)
 	ScopedLock lock(&videolock);
 	DriverEntry* drvent = CurrentDriverEntry();
 	if ( !drvent ) { Error::Set(EINVAL); return -1; }
-	return drvent->driver->WriteAt(off, buf, count);
+	return drvent->driver->ReadAt(off, buf, count);
 }
 
 } // namespace Video