--- a/simtool/writecmd.c	Sun Mar 07 03:58:49 2021 +0000
+++ b/simtool/writecmd.c	Sun Mar 07 04:06:39 2021 +0000
@@ -1,6 +1,8 @@
 #include <sys/types.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <strings.h>
 #include "curfile.h"
 
 cmd_update_bin(argc, argv)
@@ -44,15 +46,21 @@
 cmd_update_rec(argc, argv)
 	char **argv;
 {
-	unsigned recno;
+	unsigned recno, mode;
 	u_char data[255];
 	int rc;
 
-	recno = strtoul(argv[1], 0, 0);
-	if (recno < 1 || recno > 255) {
-		fprintf(stderr,
+	if (!strcmp(argv[1], "prev")) {
+		recno = 0;
+		mode = 0x03;
+	} else {
+		recno = strtoul(argv[1], 0, 0);
+		if (recno < 1 || recno > 255) {
+			fprintf(stderr,
 			"error: record number argument is out of range\n");
-		return(-1);
+			return(-1);
+		}
+		mode = 0x04;
 	}
 	rc = read_hex_data_file(argv[2], data, 255);
 	if (rc < 0)
@@ -61,21 +69,5 @@
 		fprintf(stderr, "error: hex data length != EF record length\n");
 		return(-1);
 	}
-	return update_rec_op(recno, 0x04, data, curfile_record_len);
+	return update_rec_op(recno, mode, data, curfile_record_len);
 }
-
-cmd_update_rec_prev(argc, argv)
-	char **argv;
-{
-	u_char data[255];
-	int rc;
-
-	rc = read_hex_data_file(argv[1], data, 255);
-	if (rc < 0)
-		return(rc);
-	if (rc != curfile_record_len) {
-		fprintf(stderr, "error: hex data length != EF record length\n");
-		return(-1);
-	}
-	return update_rec_op(0, 0x03, data, curfile_record_len);
-}