Made the directory functions compatible with the Commander X16's DOS.

It's directory listing's last line says, "mb free."

include/cbm.h

@@ -191,6 +191,8 @@ unsigned char cbm_k_acptr (void);
 unsigned char cbm_k_basin (void);
 void __fastcall__ cbm_k_bsout (unsigned char C);
 unsigned char __fastcall__ cbm_k_chkin (unsigned char FN);
+unsigned char cbm_k_chrin (void);
+void __fastcall__ cbm_k_chrout (unsigned char C);
 void __fastcall__ cbm_k_ciout (unsigned char C);
 unsigned char __fastcall__ cbm_k_ckout (unsigned char FN);
 void cbm_k_clall (void);
@@ -295,7 +297,15 @@ unsigned char __fastcall__ cbm_readdir (unsigned char lfn,
 /* Reads one directory line into cbm_dirent structure.
 ** Returns 0 if reading directory-line was successful.
 ** Returns non-zero if reading directory failed, or no more file-names to read.
-** Returns 2 on last line.  Then, l_dirent->size = the number of "blocks free."
+** Returns 2 on last line.  Then, l_dirent->size = the number of "blocks free",
+** "blocks used", or "mb free".  Return codes:
+** 0 = read file-name
+** 1 = couldn't read directory
+** 2 = read "blocks free", "blocks used", or "mb free"
+** 3 = couldn't find start of file-name
+** 4 = couldn't find end of file-name
+** 5 = couldn't read file-type
+** 6 = premature end of file
 */
 
 void __fastcall__ cbm_closedir (unsigned char lfn);

libsrc/cbm/c_basin.s

@@ -2,14 +2,16 @@
 ; Ullrich von Bassewitz, 03.06.1999
 ;
 ; unsigned char cbm_k_basin (void);
+; unsigned char cbm_k_chrin (void);
 ;
 
         .include        "cbm.inc"
 
-        .export         _cbm_k_basin
+        .export         _cbm_k_basin, _cbm_k_chrin
 
 
 _cbm_k_basin:
+_cbm_k_chrin:
         jsr     BASIN
         ldx     #0              ; Clear high byte
         rts

libsrc/cbm/c_bsout.s

@@ -2,10 +2,12 @@
 ; Ullrich von Bassewitz, 03.06.1999
 ;
 ; void __fastcall__ cbm_k_bsout (unsigned char C);
+; void __fastcall__ cbm_k_chrout (unsigned char C);
 ;
 
         .include        "cbm.inc"
 
-        .export         _cbm_k_bsout
+        .export         _cbm_k_bsout, _cbm_k_chrout
 
-_cbm_k_bsout = BSOUT
+_cbm_k_bsout  := BSOUT
+_cbm_k_chrout := CHROUT

libsrc/cbm/cbm_dir.c

@@ -6,6 +6,7 @@
 /* 2009-10-10 -- Version 0.3 */
 /* 2011-04-07 -- Version 0.4, groepaz */
 /* 2011-04-14 -- Version 0.5, Greg King */
+/* 2021-02-15 -- Version 0.6, Greg King */
 
 /* Tested with floppy-drive and IDE64 devices.        */
 /* Not tested with messed (buggy) directory listings. */
@@ -29,7 +30,7 @@ unsigned char cbm_opendir (unsigned char lfn, unsigned char device, ...)
     va_list ap;
     const char* name = "$";
 
-    /* The name used in cbm_open may optionally be passed */
+    /* The name used in cbm_open() optionally may be passed */
     if (__argsize__ == 4) {
         va_start (ap, device);
         name = va_arg (ap, const char*);
@@ -76,9 +77,10 @@ unsigned char __fastcall__ cbm_readdir (unsigned char lfn, register struct cbm_d
 
             byte = cbm_k_basin();
             switch (byte) {
-
+                /* "B" BLOCKS FREE/USED. */
-                /* "B" BLOCKS FREE. */
+                /* "M" MB FREE. */
               case 'b':
+              case 'm':
                 /* Read until end; careless callers might call us again. */
                 while (!cbm_k_readst()) {
                     cbm_k_basin();
@@ -168,7 +170,6 @@ unsigned char __fastcall__ cbm_readdir (unsigned char lfn, register struct cbm_d
             }
 
             rv = 0;
-            goto ret_val;
         }
     }
 

libsrc/cbm/readdir.c

@@ -1,5 +1,7 @@
 /*
-** Ullrich von Bassewitz, 2012-05-30. Based on code by Groepaz.
+** Based on code by Groepaz.
+** 2012-05-30, Ullrich von Bassewitz
+** 2021-02-15, Greg King
 */
 
 
@@ -52,12 +54,14 @@ struct dirent* __fastcall__ readdir (register DIR* dir)
     /* Bump the directory offset and include the bytes for line-link and size */
     dir->off += count + 4;
 
-    /* End of directory is reached if the buffer contains "blocks free". It is
+    /* End of directory is reached if the buffer contains "blocks free/used" or
-    ** sufficient here to check for the leading 'b'. buffer will contain at
+    ** "mb free.". It is sufficient here to check for the leading 'b' and 'm'.
-    ** least one byte if we come here.
+    ** buffer will contain at least one byte if we come here.
     */
-    if (buffer[0] == 'b') {
+    switch (buffer[0]) {
-        goto exitpoint;
+        case 'b':
+        case 'm':
+            goto exitpoint;
     }
 
     /* Parse the buffer for the filename and file type */
@@ -67,7 +71,6 @@ struct dirent* __fastcall__ readdir (register DIR* dir)
     b = buffer;
     while (i < count) {
         switch (s) {
-
             case 0:
                 /* Searching for start of file name */
                 if (*b == '"') {
@@ -127,6 +130,3 @@ struct dirent* __fastcall__ readdir (register DIR* dir)
 exitpoint:
     return 0;
 }
-
-
-