1 files changed, 4 insertions, 0 deletions
diff --git a/bas.c b/bas.c
index 24508e4..ab02b28 100644
--- a/bas.c
+++ b/bas.c
@@ -217,6 +217,10 @@ int vntable_ok(void) {
 
 		/* numbers and letters are allowed, inverse or normal. */
 		c &= 0x7f;
+		if(c == '_') {
+			fprintf(stderr, "%s: Underscore in variable name; Turbo or BASIC XE?\n", self);
+			continue;
+		}
 		if(c >= 0x30 && c <= 0x39) continue;
 		if(c >= 0x41 && c <= 0x5a) continue;