bas.c: handle weirdness when VNTP > $100 (e.g. SPIDER.TB).

1 files changed, 11 insertions, 0 deletions

diff --git a/bas.c b/bas.c
index 94ba310..5321070 100644
--- a/bas.c
+++ b/bas.c
@@ -103,6 +103,8 @@ void dump_header_vars(void) {
 }
 
 void parse_header(void) {
+	int vntp_offset;
+
 	lomem = getword(0);
 	vntp = getword(2);
 	vntd = getword(4);
@@ -110,11 +112,20 @@ void parse_header(void) {
 	stmtab = getword(8);
 	stmcur = getword(10);
 	starp = getword(12);
+
 	codestart = stmtab - TBL_OFFSET - (vntp - 256);
 	vnstart = vntp - TBL_OFFSET;
 	vvstart = vvtp - TBL_OFFSET;
 	code_end = starp - TBL_OFFSET;
 
+	if(vnstart > 0x0e) {
+		if(verbose)
+			fprintf(stderr, "VNTP is $%02x (not ($100), adjusting pointers.\n", vntp);
+		vntp_offset = vnstart - 0x0e;
+		vnstart -= vntp_offset;
+		vvstart -= vntp_offset;
+	}
+
 	if(filelen < code_end) {
 		fprintf(stderr, "Warning: file is truncated: %d bytes, should be %d.\n", filelen, code_end);
 	}