Support for reading and writing tape errors and gaps.

larsbrinkhoff · Apr 13, 2022 · d756320 · d756320
1 parent a54fde6
commit d756320
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diff --git a/dis.h b/dis.h
@@ -120,13 +120,16 @@ extern void	by_five_octets (FILE *f, int position);
 extern void	by_eight_octets (FILE *f, int position);
 extern void	write_word (FILE *, word_t);
 extern void	flush_word (FILE *);
+extern void     (*tape_hook) (int code);
 extern int      get_7track_record (FILE *f, word_t **buffer);
 extern int      get_9track_record (FILE *f, word_t **buffer);
 extern void     write_7track_record (FILE *f, word_t *buffer, int);
 extern void     write_9track_record (FILE *f, word_t *buffer, int);
 extern void     write_tape_mark (FILE *f);
 extern void     write_tape_eof (FILE *f);
 extern void     write_tape_eot (FILE *f);
+extern void     write_tape_gap (FILE *f, unsigned code);
+extern void     write_tape_error (FILE *f, unsigned code);
 extern word_t	get_core_word (FILE *f);
 extern void	write_core_word (FILE *f, word_t word);
 extern void	read_raw_at (FILE *f, struct pdp10_memory *memory,

diff --git a/main.c b/main.c
@@ -22,6 +22,23 @@
 #include "opcode/pdp10.h"
 #include "memory.h"
 
+static void
+tape_special (int code)
+{
+  switch ((code >> 24) & 0xFF)
+    {
+    case 0x80:
+      fprintf (output_file, "Tape error %06x.\n", code & 0xFFFFFF);
+      break;
+    case 0xFF:
+      fprintf (output_file, "Tape gap (%06x).\n", code & 0xFFFFFF);
+      break;
+    default:
+      fprintf (output_file, "Tape special (%08x).\n", code);
+      break;
+    }
+}
+
 static void
 usage (char **argv)
 {
@@ -93,6 +110,8 @@ main (int argc, char **argv)
 
   init_memory (&memory);
 
+  tape_hook = tape_special;
+
   if (!input_file_format)
     guess_input_file_format (file);
   input_file_format->read (file, &memory, cpu_model);

diff --git a/tape-word.c b/tape-word.c
@@ -23,6 +23,11 @@ static int reclen = 0;
 static int beginning_of_tape = 1;
 static int marks = 0;
 
+static void tape_special (int code);
+static int get_tape_record (FILE *f, word_t **buffer);
+
+void (*tape_hook) (int code) = tape_special;
+
 static int
 get_byte (FILE *f)
 {
@@ -84,6 +89,22 @@ static void write_reclen (FILE *f, int n)
     marks = 0;
 }
 
+static void tape_special (int code)
+{
+  switch ((code >> 24) & 0xFF)
+    {
+    case 0x80:
+      fprintf (stderr, "Tape error %06x.\n", code & 0xFFFFFF);
+      break;
+    case 0xFF:
+      fprintf (stderr, "Tape gap (%06x).\n", code & 0xFFFFFF);
+      break;
+    default:
+      fprintf (stderr, "Tape special (%08x).\n", code);
+      break;
+    }
+}
+
 int get_9track_record (FILE *f, word_t **buffer)
 {
   int i, x, reclen;
@@ -92,6 +113,12 @@ int get_9track_record (FILE *f, word_t **buffer)
   reclen = get_reclen (f);
   if (reclen == 0)
     return 0;
+  else if (reclen & 0x80000000)
+    {
+      tape_hook (reclen);
+      return get_tape_record (f, buffer);
+    }
+
   if (reclen % 5)
     {
       fprintf (stderr, "Not a CORE DUMP tape image.\n"
@@ -182,6 +209,12 @@ int get_7track_record (FILE *f, word_t **buffer)
   reclen = get_reclen (f);
   if (reclen == 0)
     return 0;
+  else if (reclen & 0x80000000)
+    {
+      tape_hook (reclen);
+      return get_tape_record (f, buffer);
+    }
+
   if (reclen % 6)
     {
       fprintf (stderr, "Not a 7-track tape image.\n"
@@ -310,6 +343,18 @@ write_tape_eot (FILE *f)
     write_tape_mark (f);
 }
 
+void
+write_tape_gap (FILE *f, unsigned code)
+{
+  write_reclen (f, 0xFF000000 | (code & 0xFFFFFF));
+}
+
+void
+write_tape_error (FILE *f, unsigned code)
+{
+  write_reclen (f, 0x80000000 | (code & 0xFFFFFF));
+}
+
 static void
 flush_record (FILE *f)
 {