Could you try this patch ?

--- a/src/c/files.c
+++ b/src/c/files.c
@@ -260,9 +260,7 @@ __ATTR_STK__ short fputc(short c, FILE *f)
   if (feof(f))
     (*(short*)base)++;
 
-  if (c == 9 && tmode)
-    c = ' ';   // Translate TAB in SPACE
-  if (c=='\n' && tmode)
+  if ((c=='\n' || c == '\r') && tmode)
     {
       poke(base + f->pos++, '\r');
       if (feof(f))
diff --git a/src/c/side.c b/src/c/side.c
index 4f8d683..8c767ee 100644
--- a/src/c/side.c
+++ b/src/c/side.c
@@ -421,7 +421,6 @@ draw_char46 (unsigned short a)
 { if (stream_ptr == curs_ptr) stream_ptr = gap_ptr;           \
   c = *stream_ptr & 0x00FF;                                   \
   if (c == '\r') { stream_ptr++; c = CR; }                    \
-  if (c && c < 16 && c != CR && c != (EOF&0xFF) ) c = 255;    \
   if (c && c != (EOF&0xFF)) stream_ptr++;                     \
 }