diff --git a/lang/cem/libcc.ansi/build.lua b/lang/cem/libcc.ansi/build.lua
index ee1049d66..29c85b351 100644
--- a/lang/cem/libcc.ansi/build.lua
+++ b/lang/cem/libcc.ansi/build.lua
@@ -39,9 +39,12 @@ for _, plat in ipairs(vars.plats) do
 			"./core/math/*.c",
 			"./core/math/*.e",
 			"./core/misc/*.c",
+			"./core/printf/*.c",
+			"./core/scanf/*.c",
 			"./core/setjmp/*.c",
 			"./core/setjmp/*.e",
 			"./core/stdlib/*.c",
+			"./core/stdio/*.c",
 			"./core/string/*.c",
 			"./core/time/*.c",
 			"./sys/exit/*.c",
@@ -57,7 +60,6 @@ for _, plat in ipairs(vars.plats) do
 			"./core/stdlib/ext_fmt.h",
 			"./core/time/loc_time.h",
 			"./sys/malloc/malloc.h",
-			"./sys/stdio/loc_incl.h",
 		},
 		vars = { plat = plat }
 	}
diff --git a/lang/cem/libcc.ansi/sys/stdio/doprnt.c b/lang/cem/libcc.ansi/core/printf/doprnt.c
similarity index 96%
rename from lang/cem/libcc.ansi/sys/stdio/doprnt.c
rename to lang/cem/libcc.ansi/core/printf/doprnt.c
index 9f74c7659..3eae73f0c 100644
--- a/lang/cem/libcc.ansi/sys/stdio/doprnt.c
+++ b/lang/cem/libcc.ansi/core/printf/doprnt.c
@@ -7,7 +7,7 @@
 #include <stdio.h>
 #include <stdarg.h>
 #include <string.h>
-#include "loc_incl.h"
+#include "doprnt.h"
 
 #if ACKCONF_WANT_STDIO
 
@@ -44,15 +44,13 @@ gnum(register const char* f, int* ip, va_list* app)
 #define set_pointer(flags) /* compilation might continue */
 #endif
 
+int (*_doprnt_put)(int c);
+
 #define PUTC(c)                  \
 	do                           \
 	{                            \
-		int i = putc(c, stream); \
-		if (i == EOF)            \
-		{                        \
-			if (ferror(stream))  \
-				return -1;       \
-		}                        \
+	    if (_doprnt_put(c))      \
+		    return -1;           \
 	} while (0)
 
 /* print an ordinal number */
@@ -157,7 +155,7 @@ o_print(va_list* ap, int flags, char* s, char c, int precision, int is_signed)
 	return s;
 }
 
-int _doprnt(register const char* fmt, va_list ap, FILE* stream)
+int _doprnt(register const char* fmt, va_list ap)
 {
 	register char* s;
 	register int j;
diff --git a/lang/cem/libcc.ansi/sys/stdio/loc_incl.h b/lang/cem/libcc.ansi/core/printf/doprnt.h
similarity index 58%
rename from lang/cem/libcc.ansi/sys/stdio/loc_incl.h
rename to lang/cem/libcc.ansi/core/printf/doprnt.h
index b30d3272a..efb056d86 100644
--- a/lang/cem/libcc.ansi/sys/stdio/loc_incl.h
+++ b/lang/cem/libcc.ansi/core/printf/doprnt.h
@@ -1,29 +1,5 @@
-/*
- * loc_incl.h - local include file for stdio library
- */
-/* $Id$ */
-
-#include	<stdio.h>
-#include    <ack/config.h>
-
-#define	fileno(p)		((p)->_fd)
-#define	io_testflag(p,x)	((p)->_flags & (x))
-
-#include	<stdarg.h>
-int _doprnt(const char *format, va_list ap, FILE *stream);
-int _doscan(FILE * stream, const char *format, va_list ap);
-char *_i_compute(unsigned long val, int base, char *s, int nrdigits);
-char *_f_print(va_list *ap, int flags, char *s, char c, int precision);
-
-extern void __register_stdio_cleanup(void);
-
-FILE *popen(const char *command, const char *type);
-FILE *fdopen(int fd, const char *mode);
-
-#if	ACKCONF_WANT_STDIO_FLOAT
-char *_ecvt(long double value, int ndigit, int *decpt, int *sign);
-char *_fcvt(long double value, int ndigit, int *decpt, int *sign);
-#endif
+#ifndef DOPRNT_H
+#define DOPRNT_H
 
 #define	FL_LJUST	0x0001		/* left-justify field */
 #define	FL_SIGN		0x0002		/* sign in signed conversions */
@@ -38,3 +14,15 @@ char *_fcvt(long double value, int ndigit, int *decpt, int *sign);
 #define FL_SIGNEDCONV	0x0400		/* may contain a sign */
 #define	FL_NOASSIGN	0x0800		/* do not assign (in scanf) */
 #define	FL_NOMORE	0x1000		/* all flags collected */
+
+extern int (*_doprnt_put)(int c);
+
+extern int _doprnt(register const char* fmt, va_list ap);
+extern char* _f_print(va_list* ap, int flags, char* s, char c, int precision);
+
+#if	ACKCONF_WANT_STDIO_FLOAT
+char *_ecvt(long double value, int ndigit, int *decpt, int *sign);
+char *_fcvt(long double value, int ndigit, int *decpt, int *sign);
+#endif
+
+#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/fltpr.c b/lang/cem/libcc.ansi/core/printf/fltpr.c
similarity index 99%
rename from lang/cem/libcc.ansi/sys/stdio/fltpr.c
rename to lang/cem/libcc.ansi/core/printf/fltpr.c
index 3fdc80852..7b9f28a69 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fltpr.c
+++ b/lang/cem/libcc.ansi/core/printf/fltpr.c
@@ -5,7 +5,7 @@
 
 #include <string.h>
 #include <stdarg.h>
-#include "loc_incl.h"
+#include "doprnt.h"
 
 #if ACKCONF_WANT_STDIO && ACKCONF_WANT_STDIO_FLOAT
 
diff --git a/lang/cem/libcc.ansi/sys/stdio/fprintf.c b/lang/cem/libcc.ansi/core/printf/fprintf.c
similarity index 80%
rename from lang/cem/libcc.ansi/sys/stdio/fprintf.c
rename to lang/cem/libcc.ansi/core/printf/fprintf.c
index 3085bf96a..3be0ea66b 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fprintf.c
+++ b/lang/cem/libcc.ansi/core/printf/fprintf.c
@@ -5,7 +5,6 @@
 
 #include <stdio.h>
 #include <stdarg.h>
-#include "loc_incl.h"
 
 #if ACKCONF_WANT_STDIO
 
@@ -15,9 +14,7 @@ int fprintf(FILE* stream, const char* format, ...)
 	int retval;
 
 	va_start(ap, format);
-
-	retval = _doprnt(format, ap, stream);
-
+	retval = vfprintf(stream, format, ap);
 	va_end(ap);
 
 	return retval;
diff --git a/lang/cem/libcc.ansi/sys/stdio/icompute.c b/lang/cem/libcc.ansi/core/printf/icompute.c
similarity index 94%
rename from lang/cem/libcc.ansi/sys/stdio/icompute.c
rename to lang/cem/libcc.ansi/core/printf/icompute.c
index 9b48d51a4..7f497d107 100644
--- a/lang/cem/libcc.ansi/sys/stdio/icompute.c
+++ b/lang/cem/libcc.ansi/core/printf/icompute.c
@@ -3,7 +3,7 @@
  */
 /* $Id$ */
 
-#include "loc_incl.h"
+#include <stdio.h>
 
 #if ACKCONF_WANT_STDIO
 
diff --git a/lang/cem/libcc.ansi/sys/stdio/printf.c b/lang/cem/libcc.ansi/core/printf/printf.c
similarity index 80%
rename from lang/cem/libcc.ansi/sys/stdio/printf.c
rename to lang/cem/libcc.ansi/core/printf/printf.c
index 6b118c859..7f282456a 100644
--- a/lang/cem/libcc.ansi/sys/stdio/printf.c
+++ b/lang/cem/libcc.ansi/core/printf/printf.c
@@ -5,7 +5,6 @@
 
 #include <stdio.h>
 #include <stdarg.h>
-#include "loc_incl.h"
 
 #if ACKCONF_WANT_STDIO
 
@@ -15,9 +14,7 @@ int printf(const char* format, ...)
 	int retval;
 
 	va_start(ap, format);
-
-	retval = _doprnt(format, ap, stdout);
-
+	retval = vfprintf(stdout, format, ap);
 	va_end(ap);
 
 	return retval;
diff --git a/lang/cem/libcc.ansi/core/printf/snprintf.c b/lang/cem/libcc.ansi/core/printf/snprintf.c
new file mode 100644
index 000000000..5342785ab
--- /dev/null
+++ b/lang/cem/libcc.ansi/core/printf/snprintf.c
@@ -0,0 +1,23 @@
+/*
+ * sprintf - print formatted output on an array
+ */
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#if ACKCONF_WANT_STDIO
+
+int snprintf(char* s, size_t len, const char* format, ...)
+{
+	va_list ap;
+	int retval;
+
+	va_start(ap, format);
+	retval = vsnprintf(s, len, format, ap);
+	va_end(ap);
+
+	return retval;
+}
+
+#endif
diff --git a/lang/cem/libcc.ansi/core/printf/sprintf.c b/lang/cem/libcc.ansi/core/printf/sprintf.c
new file mode 100644
index 000000000..86e81e4a4
--- /dev/null
+++ b/lang/cem/libcc.ansi/core/printf/sprintf.c
@@ -0,0 +1,23 @@
+/*
+ * sprintf - print formatted output on an array
+ */
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#if ACKCONF_WANT_STDIO
+
+int sprintf(char* s, const char* format, ...)
+{
+	va_list ap;
+	int retval;
+
+	va_start(ap, format);
+	retval = vsnprintf(s, 32767, format, ap);
+	va_end(ap);
+
+	return retval;
+}
+
+#endif
diff --git a/lang/cem/libcc.ansi/core/printf/vfprintf.c b/lang/cem/libcc.ansi/core/printf/vfprintf.c
new file mode 100644
index 000000000..7e665a22f
--- /dev/null
+++ b/lang/cem/libcc.ansi/core/printf/vfprintf.c
@@ -0,0 +1,27 @@
+/*
+ * vfprintf - formatted output without ellipsis
+ */
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include "doprnt.h"
+
+#if ACKCONF_WANT_STDIO
+
+static FILE* vfprintf_stream;
+
+static int vfprintf_putc(int c)
+{
+	putc(c, vfprintf_stream);
+	return ferror(vfprintf_stream);
+}
+
+int vfprintf(FILE* stream, const char* format, va_list arg)
+{
+	vfprintf_stream = stream;
+	_doprnt_put = vfprintf_putc;
+	return _doprnt(format, arg);
+}
+
+#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/vprintf.c b/lang/cem/libcc.ansi/core/printf/vprintf.c
similarity index 78%
rename from lang/cem/libcc.ansi/sys/stdio/vprintf.c
rename to lang/cem/libcc.ansi/core/printf/vprintf.c
index 5cc6b837f..999fdaa4d 100644
--- a/lang/cem/libcc.ansi/sys/stdio/vprintf.c
+++ b/lang/cem/libcc.ansi/core/printf/vprintf.c
@@ -5,13 +5,12 @@
 
 #include <stdio.h>
 #include <stdarg.h>
-#include "loc_incl.h"
 
 #if ACKCONF_WANT_STDIO
 
 int vprintf(const char* format, va_list arg)
 {
-	return _doprnt(format, arg, stdout);
+	return vfprintf(stdout, format, arg);
 }
 
 #endif
diff --git a/lang/cem/libcc.ansi/core/printf/vsnprintf.c b/lang/cem/libcc.ansi/core/printf/vsnprintf.c
new file mode 100644
index 000000000..af97b5351
--- /dev/null
+++ b/lang/cem/libcc.ansi/core/printf/vsnprintf.c
@@ -0,0 +1,38 @@
+/*
+ * vsprintf - print formatted output without ellipsis on an array
+ */
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include "doprnt.h"
+
+#if ACKCONF_WANT_STDIO
+
+static char* output_buffer;
+static size_t output_buffer_len;
+
+static int snprintf_putc(int c)
+{
+	if (output_buffer_len)
+	{
+		*output_buffer++ = c;
+		output_buffer_len--;
+	}
+	return 0;
+}
+
+int vsnprintf(char* s, size_t len, const char* format, va_list ap)
+{
+	int retval;
+
+	output_buffer = s;
+	output_buffer_len = len;
+	_doprnt_put = snprintf_putc;
+	retval = _doprnt(format, ap);
+	snprintf_putc('\0');
+
+	return retval;
+}
+
+#endif
diff --git a/lang/cem/libcc.ansi/core/printf/vsprintf.c b/lang/cem/libcc.ansi/core/printf/vsprintf.c
new file mode 100644
index 000000000..c8da509ab
--- /dev/null
+++ b/lang/cem/libcc.ansi/core/printf/vsprintf.c
@@ -0,0 +1,16 @@
+/*
+ * vsprintf - print formatted output without ellipsis on an array
+ */
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#if ACKCONF_WANT_STDIO
+
+int vsprintf(char* s, const char* format, va_list ap)
+{
+	return vsnprintf(s, 32767, format, ap);
+}
+
+#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/doscan.c b/lang/cem/libcc.ansi/core/scanf/doscan.c
similarity index 90%
rename from lang/cem/libcc.ansi/sys/stdio/doscan.c
rename to lang/cem/libcc.ansi/core/scanf/doscan.c
index 3a1076bad..97cf777a2 100644
--- a/lang/cem/libcc.ansi/sys/stdio/doscan.c
+++ b/lang/cem/libcc.ansi/core/scanf/doscan.c
@@ -7,7 +7,7 @@
 #include <stdlib.h>
 #include <ctype.h>
 #include <stdarg.h>
-#include "loc_incl.h"
+#include "doscan.h"
 
 #if ACKCONF_WANT_STDIO
 
@@ -26,15 +26,16 @@
 static char Xtable[NR_CHARS];
 static char inp_buf[NUMLEN];
 
+int (*_doscan_get)(void);
+void (*_doscan_unget)(int c);
+
 /* Collect a number of characters which constitite an ordinal number.
  * When the type is 'i', the base can be 8, 10, or 16, depending on the
  * first 1 or 2 characters. This means that the base must be adjusted
  * according to the format of the number. At the end of the function, base
  * is then set to 0, so strtol() will get the right argument.
  */
-static char*
-o_collect(register int c, register FILE* stream, char type,
-    int width, int* basep)
+static char* o_collect(register int c, char type, int width, int* basep)
 {
 	register char* bufp = inp_buf;
 	register int base;
@@ -63,14 +64,14 @@ o_collect(register int c, register FILE* stream, char type,
 	{
 		*bufp++ = c;
 		if (--width)
-			c = getc(stream);
+			c = _doscan_get();
 	}
 
 	if (width && c == '0' && base == 16)
 	{
 		*bufp++ = c;
 		if (--width)
-			c = getc(stream);
+			c = _doscan_get();
 		if (c != 'x' && c != 'X')
 		{
 			if (type == 'i')
@@ -80,7 +81,7 @@ o_collect(register int c, register FILE* stream, char type,
 		{
 			*bufp++ = c;
 			if (--width)
-				c = getc(stream);
+				c = _doscan_get();
 		}
 	}
 	else if (type == 'i')
@@ -95,14 +96,14 @@ o_collect(register int c, register FILE* stream, char type,
 		{
 			*bufp++ = c;
 			if (--width)
-				c = getc(stream);
+				c = _doscan_get();
 		}
 		else
 			break;
 	}
 
 	if (width && c != EOF)
-		ungetc(c, stream);
+		_doscan_unget(c);
 	if (type == 'i')
 		base = 0;
 	*basep = base;
@@ -119,8 +120,7 @@ o_collect(register int c, register FILE* stream, char type,
  * not necessary, although the use of the width field can cause incomplete
  * numbers to be passed to strtod(). (e.g. 1.3e+)
  */
-static char*
-f_collect(register int c, register FILE* stream, register int width)
+static char* f_collect(register int c, register int width)
 {
 	register char* bufp = inp_buf;
 	int digit_seen = 0;
@@ -129,7 +129,7 @@ f_collect(register int c, register FILE* stream, register int width)
 	{
 		*bufp++ = c;
 		if (--width)
-			c = getc(stream);
+			c = _doscan_get();
 	}
 
 	while (width && isdigit(c))
@@ -137,26 +137,26 @@ f_collect(register int c, register FILE* stream, register int width)
 		digit_seen++;
 		*bufp++ = c;
 		if (--width)
-			c = getc(stream);
+			c = _doscan_get();
 	}
 	if (width && c == '.')
 	{
 		*bufp++ = c;
 		if (--width)
-			c = getc(stream);
+			c = _doscan_get();
 		while (width && isdigit(c))
 		{
 			digit_seen++;
 			*bufp++ = c;
 			if (--width)
-				c = getc(stream);
+				c = _doscan_get();
 		}
 	}
 
 	if (!digit_seen)
 	{
 		if (width && c != EOF)
-			ungetc(c, stream);
+			_doscan_unget(c);
 		return inp_buf - 1;
 	}
 	else
@@ -166,30 +166,30 @@ f_collect(register int c, register FILE* stream, register int width)
 	{
 		*bufp++ = c;
 		if (--width)
-			c = getc(stream);
+			c = _doscan_get();
 		if (width && (c == '+' || c == '-'))
 		{
 			*bufp++ = c;
 			if (--width)
-				c = getc(stream);
+				c = _doscan_get();
 		}
 		while (width && isdigit(c))
 		{
 			digit_seen++;
 			*bufp++ = c;
 			if (--width)
-				c = getc(stream);
+				c = _doscan_get();
 		}
 		if (!digit_seen)
 		{
 			if (width && c != EOF)
-				ungetc(c, stream);
+				_doscan_unget(c);
 			return inp_buf - 1;
 		}
 	}
 
 	if (width && c != EOF)
-		ungetc(c, stream);
+		_doscan_unget(c);
 	*bufp = '\0';
 	return bufp - 1;
 }
@@ -199,7 +199,7 @@ f_collect(register int c, register FILE* stream, register int width)
  * the routine that does the scanning 
  */
 
-int _doscan(register FILE* stream, const char* format, va_list ap)
+int _doscan(const char* format, va_list ap)
 {
 	int done = 0; /* number of items done */
 	int nrchars = 0; /* number of characters read */
@@ -226,15 +226,15 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 		{
 			while (isspace(*format))
 				format++; /* skip whitespace */
-			ic = getc(stream);
+			ic = _doscan_get();
 			nrchars++;
 			while (isspace(ic))
 			{
-				ic = getc(stream);
+				ic = _doscan_get();
 				nrchars++;
 			}
 			if (ic != EOF)
-				ungetc(ic, stream);
+				_doscan_unget(ic);
 			nrchars--;
 		}
 		if (!*format)
@@ -242,12 +242,12 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 
 		if (*format != '%')
 		{
-			ic = getc(stream);
+			ic = _doscan_get();
 			nrchars++;
 			if (ic != *format++)
 			{
 				if (ic != EOF)
-					ungetc(ic, stream);
+					_doscan_unget(ic);
 				nrchars--;
 				break; /* error */
 			}
@@ -256,7 +256,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 		format++;
 		if (*format == '%')
 		{
-			ic = getc(stream);
+			ic = _doscan_get();
 			nrchars++;
 			if (ic == '%')
 			{
@@ -299,7 +299,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 		{
 			do
 			{
-				ic = getc(stream);
+				ic = _doscan_get();
 				nrchars++;
 			} while (isspace(ic));
 			if (ic == EOF)
@@ -307,7 +307,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 		}
 		else if (kind != 'n')
 		{ /* %c or %[ */
-			ic = getc(stream);
+			ic = _doscan_get();
 			if (ic == EOF)
 				break; /* outer while */
 			nrchars++;
@@ -344,7 +344,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 				if (!width)
 					return done;
 
-				str = o_collect(ic, stream, kind, width, &base);
+				str = o_collect(ic, kind, width, &base);
 				if (str < inp_buf
 				    || (str == inp_buf
 				           && (*str == '-'
@@ -385,7 +385,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 						*str++ = (char)ic;
 					if (--width)
 					{
-						ic = getc(stream);
+						ic = _doscan_get();
 						nrchars++;
 					}
 				}
@@ -393,7 +393,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 				if (width)
 				{
 					if (ic != EOF)
-						ungetc(ic, stream);
+						_doscan_unget(ic);
 					nrchars--;
 				}
 				break;
@@ -411,7 +411,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 						*str++ = (char)ic;
 					if (--width)
 					{
-						ic = getc(stream);
+						ic = _doscan_get();
 						nrchars++;
 					}
 				}
@@ -421,7 +421,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 				if (width)
 				{
 					if (ic != EOF)
-						ungetc(ic, stream);
+						_doscan_unget(ic);
 					nrchars--;
 				}
 				break;
@@ -468,7 +468,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 				if (!*format || !(Xtable[ic] ^ reverse))
 				{
 					if (ic != EOF)
-						ungetc(ic, stream);
+						_doscan_unget(ic);
 					return done;
 				}
 
@@ -481,7 +481,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 						*str++ = (char)ic;
 					if (--width)
 					{
-						ic = getc(stream);
+						ic = _doscan_get();
 						nrchars++;
 					}
 				} while (width && ic != EOF && (Xtable[ic] ^ reverse));
@@ -489,7 +489,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 				if (width)
 				{
 					if (ic != EOF)
-						ungetc(ic, stream);
+						_doscan_unget(ic);
 					nrchars--;
 				}
 				if (!(flags & FL_NOASSIGN))
@@ -508,7 +508,7 @@ int _doscan(register FILE* stream, const char* format, va_list ap)
 
 				if (!width)
 					return done;
-				str = f_collect(ic, stream, width);
+				str = f_collect(ic, width);
 
 				if (str < inp_buf
 				    || (str == inp_buf
diff --git a/lang/cem/libcc.ansi/core/scanf/doscan.h b/lang/cem/libcc.ansi/core/scanf/doscan.h
new file mode 100644
index 000000000..2502ea8e8
--- /dev/null
+++ b/lang/cem/libcc.ansi/core/scanf/doscan.h
@@ -0,0 +1,23 @@
+#ifndef DOSCAN_H
+#define DOSCAN_H
+
+#define	FL_LJUST	0x0001		/* left-justify field */
+#define	FL_SIGN		0x0002		/* sign in signed conversions */
+#define	FL_SPACE	0x0004		/* space in signed conversions */
+#define	FL_ALT		0x0008		/* alternate form */
+#define	FL_ZEROFILL	0x0010		/* fill with zero's */
+#define	FL_SHORT	0x0020		/* optional h */
+#define	FL_LONG		0x0040		/* optional l */
+#define	FL_LONGDOUBLE	0x0080		/* optional L */
+#define	FL_WIDTHSPEC	0x0100		/* field width is specified */
+#define	FL_PRECSPEC	0x0200		/* precision is specified */
+#define FL_SIGNEDCONV	0x0400		/* may contain a sign */
+#define	FL_NOASSIGN	0x0800		/* do not assign (in scanf) */
+#define	FL_NOMORE	0x1000		/* all flags collected */
+
+extern int (*_doscan_get)(void);
+extern void (*_doscan_unget)(int c);
+
+extern int _doscan(const char* format, va_list ap);
+
+#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/fscanf.c b/lang/cem/libcc.ansi/core/scanf/fscanf.c
similarity index 81%
rename from lang/cem/libcc.ansi/sys/stdio/fscanf.c
rename to lang/cem/libcc.ansi/core/scanf/fscanf.c
index b06d47253..21fd6c8ee 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fscanf.c
+++ b/lang/cem/libcc.ansi/core/scanf/fscanf.c
@@ -5,7 +5,6 @@
 
 #include <stdio.h>
 #include <stdarg.h>
-#include "loc_incl.h"
 
 #if ACKCONF_WANT_STDIO
 
@@ -15,9 +14,7 @@ int fscanf(FILE* stream, const char* format, ...)
 	int retval;
 
 	va_start(ap, format);
-
-	retval = _doscan(stream, format, ap);
-
+	retval = vfscanf(stream, format, ap);
 	va_end(ap);
 
 	return retval;
diff --git a/lang/cem/libcc.ansi/sys/stdio/scanf.c b/lang/cem/libcc.ansi/core/scanf/scanf.c
similarity index 81%
rename from lang/cem/libcc.ansi/sys/stdio/scanf.c
rename to lang/cem/libcc.ansi/core/scanf/scanf.c
index d52788084..6796013cf 100644
--- a/lang/cem/libcc.ansi/sys/stdio/scanf.c
+++ b/lang/cem/libcc.ansi/core/scanf/scanf.c
@@ -5,7 +5,6 @@
 
 #include <stdio.h>
 #include <stdarg.h>
-#include "loc_incl.h"
 
 #if ACKCONF_WANT_STDIO
 
@@ -15,9 +14,7 @@ int scanf(const char* format, ...)
 	int retval;
 
 	va_start(ap, format);
-
-	retval = _doscan(stdin, format, ap);
-
+	retval = vfscanf(stdin, format, ap);
 	va_end(ap);
 
 	return retval;
diff --git a/lang/cem/libcc.ansi/core/scanf/sscanf.c b/lang/cem/libcc.ansi/core/scanf/sscanf.c
new file mode 100644
index 000000000..eb972eeb2
--- /dev/null
+++ b/lang/cem/libcc.ansi/core/scanf/sscanf.c
@@ -0,0 +1,47 @@
+/*
+ * sscanf - read formatted output from a string
+ */
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include "doscan.h"
+
+#if ACKCONF_WANT_STDIO
+
+static const char* input_buffer;
+
+static int sscanf_getc(void)
+{
+	char c = *input_buffer;
+	if (c == 0)
+		return EOF;
+	input_buffer++;
+	return c;
+}
+
+static void sscanf_ungetc(int c)
+{
+	/* sscanf always ungets the last character read. */
+	input_buffer--;
+}
+
+int sscanf(const char* s, const char* format, ...)
+{
+	va_list ap;
+	int retval;
+
+	va_start(ap, format);
+
+	input_buffer = s;
+	_doscan_get = sscanf_getc;
+	_doscan_unget = sscanf_ungetc;
+	retval = _doscan(format, ap);
+
+	va_end(ap);
+
+	return retval;
+}
+
+#endif
diff --git a/lang/cem/libcc.ansi/core/scanf/vfscanf.c b/lang/cem/libcc.ansi/core/scanf/vfscanf.c
new file mode 100644
index 000000000..c5a562049
--- /dev/null
+++ b/lang/cem/libcc.ansi/core/scanf/vfscanf.c
@@ -0,0 +1,32 @@
+/*
+ * vfscanf.c - read formatted input from stream
+ */
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include "doscan.h"
+
+#if ACKCONF_WANT_STDIO
+
+static FILE* vfscanf_stream;
+
+static int vfscanf_getc(void)
+{
+	return getc(vfscanf_stream);
+}
+
+static void vfscanf_ungetc(int c)
+{
+	ungetc(c, vfscanf_stream);
+}
+
+int vfscanf(FILE* stream, const char* format, va_list ap)
+{
+	vfscanf_stream = stream;
+	_doscan_get = vfscanf_getc;
+	_doscan_unget = vfscanf_ungetc;
+	return _doscan(format, ap);
+}
+
+#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/clearerr.c b/lang/cem/libcc.ansi/core/stdio/clearerr.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/clearerr.c
rename to lang/cem/libcc.ansi/core/stdio/clearerr.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/feof.c b/lang/cem/libcc.ansi/core/stdio/feof.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/feof.c
rename to lang/cem/libcc.ansi/core/stdio/feof.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/ferror.c b/lang/cem/libcc.ansi/core/stdio/ferror.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/ferror.c
rename to lang/cem/libcc.ansi/core/stdio/ferror.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/fgetc.c b/lang/cem/libcc.ansi/core/stdio/fgetc.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/fgetc.c
rename to lang/cem/libcc.ansi/core/stdio/fgetc.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/fgets.c b/lang/cem/libcc.ansi/core/stdio/fgets.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/fgets.c
rename to lang/cem/libcc.ansi/core/stdio/fgets.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/fputc.c b/lang/cem/libcc.ansi/core/stdio/fputc.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/fputc.c
rename to lang/cem/libcc.ansi/core/stdio/fputc.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/fputs.c b/lang/cem/libcc.ansi/core/stdio/fputs.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/fputs.c
rename to lang/cem/libcc.ansi/core/stdio/fputs.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/fread.c b/lang/cem/libcc.ansi/core/stdio/fread.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/fread.c
rename to lang/cem/libcc.ansi/core/stdio/fread.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/fwrite.c b/lang/cem/libcc.ansi/core/stdio/fwrite.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/fwrite.c
rename to lang/cem/libcc.ansi/core/stdio/fwrite.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/getc.c b/lang/cem/libcc.ansi/core/stdio/getc.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/getc.c
rename to lang/cem/libcc.ansi/core/stdio/getc.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/getchar.c b/lang/cem/libcc.ansi/core/stdio/getchar.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/getchar.c
rename to lang/cem/libcc.ansi/core/stdio/getchar.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/putc.c b/lang/cem/libcc.ansi/core/stdio/putc.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/putc.c
rename to lang/cem/libcc.ansi/core/stdio/putc.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/putchar.c b/lang/cem/libcc.ansi/core/stdio/putchar.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/putchar.c
rename to lang/cem/libcc.ansi/core/stdio/putchar.c
diff --git a/lang/cem/libcc.ansi/sys/stdio/puts.c b/lang/cem/libcc.ansi/core/stdio/puts.c
similarity index 100%
rename from lang/cem/libcc.ansi/sys/stdio/puts.c
rename to lang/cem/libcc.ansi/core/stdio/puts.c
diff --git a/lang/cem/libcc.ansi/headers/ack/config.h b/lang/cem/libcc.ansi/headers/ack/config.h
index 2ee784213..41e9bc3b6 100644
--- a/lang/cem/libcc.ansi/headers/ack/config.h
+++ b/lang/cem/libcc.ansi/headers/ack/config.h
@@ -63,4 +63,9 @@
 #define ACKCONF_WANT_STDIO 1
 #endif
 
+#ifndef ACKCONF_WANT_EMULATED_FILE
+/* Implement FILE* on top of read()/write() file descriptors. */
+#define ACKCONF_WANT_EMULATED_FILE 1
+#endif
+
 #endif
diff --git a/lang/cem/libcc.ansi/headers/ack/emufile.h b/lang/cem/libcc.ansi/headers/ack/emufile.h
new file mode 100644
index 000000000..06a1ffcec
--- /dev/null
+++ b/lang/cem/libcc.ansi/headers/ack/emufile.h
@@ -0,0 +1,67 @@
+#ifndef ACK_EMUFILE_H
+#define ACK_EMUFILE_H
+
+/*
+ * Focus point of all stdio activity.
+ */
+struct FILE {
+	int		_count;
+	int		_fd;
+	int		_flags;
+	int		_bufsiz;
+	unsigned char	*_buf;
+	unsigned char	*_ptr;
+};
+
+#define	_IOFBF		0x000
+#define	_IOREAD		0x001
+#define	_IOWRITE	0x002
+#define	_IONBF		0x004
+#define	_IOMYBUF	0x008
+#define	_IOEOF		0x010
+#define	_IOERR		0x020
+#define	_IOLBF		0x040
+#define	_IOREADING	0x080
+#define _IOWRITING	0x100
+#define	_IOAPPEND	0x200
+
+#if !defined BUFSIZ
+#define	BUFSIZ      1024
+#endif
+
+#define	FOPEN_MAX	20
+extern FILE	*__iotab[FOPEN_MAX];
+
+#define	stdin       (&__stdin)
+#define	stdout      (&__stdout)
+#define	stderr      (&__stderr)
+extern FILE	__stdin, __stdout, __stderr;
+
+#define	FILENAME_MAX 255
+#define	TMP_MAX     999
+#define	L_tmpnam    (sizeof("/tmp/") + 15)
+#define ACK_TMP_PREFIX "/tmp/tmp."
+
+extern int __fillbuf(FILE *_stream);
+extern int __flushbuf(int _c, FILE *_stream);
+
+#define	getc(p)		(--(p)->_count >= 0 ? (int) (*(p)->_ptr++) : \
+				__fillbuf(p))
+#define	putc(c, p)	(--(p)->_count >= 0 ? \
+			 (int) (*(p)->_ptr++ = (c)) : \
+			 __flushbuf((c),(p)))
+
+#define	feof(p)		(((p)->_flags & _IOEOF) != 0)
+#define	ferror(p)	(((p)->_flags & _IOERR) != 0)
+#define clearerr(p)	((p)->_flags &= ~(_IOERR|_IOEOF))
+
+/* Non-standard extensions */
+
+extern int fileno(FILE *_stream);
+extern FILE* fdopen(int fildes, const char *type);
+#define	fileno(stream) ((stream)->_fd)
+
+#define	io_testflag(p,x)	((p)->_flags & (x))
+extern void __register_stdio_cleanup(void);
+
+#endif
diff --git a/lang/cem/libcc.ansi/headers/stdio.h b/lang/cem/libcc.ansi/headers/stdio.h
index 52f286f20..c6ddb8808 100644
--- a/lang/cem/libcc.ansi/headers/stdio.h
+++ b/lang/cem/libcc.ansi/headers/stdio.h
@@ -10,53 +10,21 @@
 #define	_STDIO_H
 
 #include <stddef.h>
+#include <stdarg.h>
+#include <ack/config.h>
 
-/*
- * Focus point of all stdio activity.
- */
-typedef struct __iobuf {
-	int		_count;
-	int		_fd;
-	int		_flags;
-	int		_bufsiz;
-	unsigned char	*_buf;
-	unsigned char	*_ptr;
-} FILE;
+/* Public stdio entry points. */
 
-#define	_IOFBF		0x000
-#define	_IOREAD		0x001
-#define	_IOWRITE	0x002
-#define	_IONBF		0x004
-#define	_IOMYBUF	0x008
-#define	_IOEOF		0x010
-#define	_IOERR		0x020
-#define	_IOLBF		0x040
-#define	_IOREADING	0x080
-#define _IOWRITING	0x100
-#define	_IOAPPEND	0x200
+typedef struct FILE FILE;
+
+#define	EOF         (-1)
 
 #define	SEEK_SET    0
 #define	SEEK_CUR    1
 #define	SEEK_END    2
 
-#define	stdin       (&__stdin)
-#define	stdout      (&__stdout)
-#define	stderr      (&__stderr)
-
-#define	BUFSIZ      1024
-#define	EOF         (-1)
-
-#define	FOPEN_MAX	20
-
-#define	FILENAME_MAX 255
-#define	TMP_MAX     999
-#define	L_tmpnam    (sizeof("/tmp/") + 15)
-
 typedef long int fpos_t;
 
-extern FILE	*__iotab[FOPEN_MAX];
-extern FILE	__stdin, __stdout, __stderr;
-
 extern int	remove(const char *_filename);
 extern int	rename(const char *_old, const char *_new);
 extern FILE	*tmpfile(void);
@@ -69,6 +37,7 @@ extern void	setbuf(FILE *_stream, char *_buf);
 extern int	setvbuf(FILE *_stream, char *_buf, int _mode, size_t _size);
 extern int	fprintf(FILE *_stream, const char *_format, ...);
 extern int	fscanf(FILE *_stream, const char *_format, ...);
+extern int	vfscanf(FILE *_stream, const char *_format, va_list ap);
 extern int	printf(const char *_format, ...);
 extern int	scanf(const char *_format, ...);
 extern int	sprintf(char *_s, const char *_format, ...);
@@ -76,8 +45,8 @@ extern int	snprintf(char *_s, size_t _len, const char *_format, ...);
 extern int	sscanf(const char *_s, const char *_format, ...);
 extern int	vfprintf(FILE *_stream, const char *_format, char *_arg);
 extern int	vprintf(const char *_format, char *_arg);
-extern int	vsprintf(char *_s, const char *_format, char *_arg);
-extern int	vsnprintf(char *_s, size_t _len, const char *_format, char *_arg);
+extern int	vsprintf(char *_s, const char *_format, va_list ap);
+extern int	vsnprintf(char *_s, size_t _len, const char *_format, va_list ap);
 extern int	fgetc(FILE *_stream);
 extern char	*fgets(char *_s, int _n, FILE *_stream);
 extern int	fputc(int _c, FILE *_stream);
@@ -101,25 +70,16 @@ extern int	feof(FILE *_stream);
 extern int	ferror(FILE *_stream);
 extern void	perror(const char *_s);
 
-extern int __fillbuf(FILE *_stream);
-extern int __flushbuf(int _c, FILE *_stream);
-
 #define	getchar()	getc(stdin)
-#define	putchar(c)	putc(c,stdout)
-#define	getc(p)		(--(p)->_count >= 0 ? (int) (*(p)->_ptr++) : \
-				__fillbuf(p))
-#define	putc(c, p)	(--(p)->_count >= 0 ? \
-			 (int) (*(p)->_ptr++ = (c)) : \
-			 __flushbuf((c),(p)))
+#define	putchar(c)	putc(c, stdout)
 
-#define	feof(p)		(((p)->_flags & _IOEOF) != 0)
-#define	ferror(p)	(((p)->_flags & _IOERR) != 0)
-#define clearerr(p)	((p)->_flags &= ~(_IOERR|_IOEOF))
+/* Internal function used in several places which is approximately itoa(). */
+extern char *_i_compute(unsigned long val, int base, char *s, int nrdigits);
 
-/* Non-standard extensions */
-
-extern int fileno(FILE *_stream);
-extern FILE* fdopen(int fildes, const char *type);
-#define	fileno(stream) ((stream)->_fd)
+#if ACKCONF_WANT_EMULATED_FILE
+#include <ack/emufile.h>
+#else
+#include <ack/file.h>
+#endif
 
 #endif	/* _STDIO_H */
diff --git a/lang/cem/libcc.ansi/sys/stdio/data.c b/lang/cem/libcc.ansi/sys/stdio/data.c
index ccf1664ce..aba91557a 100644
--- a/lang/cem/libcc.ansi/sys/stdio/data.c
+++ b/lang/cem/libcc.ansi/sys/stdio/data.c
@@ -5,19 +5,19 @@
 
 #include <stdio.h>
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
-struct __iobuf __stdin = {
+struct FILE __stdin = {
 	0, 0, _IOREAD, 0,
 	(unsigned char*)NULL, (unsigned char*)NULL,
 };
 
-struct __iobuf __stdout = {
+struct FILE __stdout = {
 	0, 1, _IOWRITE, 0,
 	(unsigned char*)NULL, (unsigned char*)NULL,
 };
 
-struct __iobuf __stderr = {
+struct FILE __stderr = {
 	0, 2, _IOWRITE | _IOLBF, 0,
 	(unsigned char*)NULL, (unsigned char*)NULL,
 };
diff --git a/lang/cem/libcc.ansi/sys/stdio/fclose.c b/lang/cem/libcc.ansi/sys/stdio/fclose.c
index 9a56b4cfe..a805a6e84 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fclose.c
+++ b/lang/cem/libcc.ansi/sys/stdio/fclose.c
@@ -6,9 +6,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 int fclose(FILE* fp)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/fdopen.c b/lang/cem/libcc.ansi/sys/stdio/fdopen.c
index 084d39c14..aff7d248e 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fdopen.c
+++ b/lang/cem/libcc.ansi/sys/stdio/fdopen.c
@@ -5,9 +5,8 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include "../stdio/loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 FILE* fdopen(int fd, const char* mode)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/fflush.c b/lang/cem/libcc.ansi/sys/stdio/fflush.c
index f0f53bb25..7746ef0fb 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fflush.c
+++ b/lang/cem/libcc.ansi/sys/stdio/fflush.c
@@ -6,9 +6,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 int fflush(FILE* stream)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/fileno.c b/lang/cem/libcc.ansi/sys/stdio/fileno.c
index e42608845..36e2b8bb9 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fileno.c
+++ b/lang/cem/libcc.ansi/sys/stdio/fileno.c
@@ -5,7 +5,7 @@
 
 #include <stdio.h>
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 int(fileno)(FILE* stream)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/fillbuf.c b/lang/cem/libcc.ansi/sys/stdio/fillbuf.c
index 75187edac..09cc5cfc6 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fillbuf.c
+++ b/lang/cem/libcc.ansi/sys/stdio/fillbuf.c
@@ -6,9 +6,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 int __fillbuf(register FILE* stream)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/flushbuf.c b/lang/cem/libcc.ansi/sys/stdio/flushbuf.c
index 81325d3a6..0cf271704 100644
--- a/lang/cem/libcc.ansi/sys/stdio/flushbuf.c
+++ b/lang/cem/libcc.ansi/sys/stdio/flushbuf.c
@@ -6,9 +6,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 static int
 do_write(int d, char* buf, int nbytes)
diff --git a/lang/cem/libcc.ansi/sys/stdio/fopen.c b/lang/cem/libcc.ansi/sys/stdio/fopen.c
index ce8c5634e..f2189ee8f 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fopen.c
+++ b/lang/cem/libcc.ansi/sys/stdio/fopen.c
@@ -8,9 +8,8 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 #define PMODE 0666
 
diff --git a/lang/cem/libcc.ansi/sys/stdio/freopen.c b/lang/cem/libcc.ansi/sys/stdio/freopen.c
index 255e04cb6..846208420 100644
--- a/lang/cem/libcc.ansi/sys/stdio/freopen.c
+++ b/lang/cem/libcc.ansi/sys/stdio/freopen.c
@@ -7,9 +7,8 @@
 #include <stdio.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 #define PMODE 0666
 
diff --git a/lang/cem/libcc.ansi/sys/stdio/fseek.c b/lang/cem/libcc.ansi/sys/stdio/fseek.c
index c1ecd5650..4ab5c10e3 100644
--- a/lang/cem/libcc.ansi/sys/stdio/fseek.c
+++ b/lang/cem/libcc.ansi/sys/stdio/fseek.c
@@ -6,9 +6,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 int fseek(FILE* stream, long int offset, int whence)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/ftell.c b/lang/cem/libcc.ansi/sys/stdio/ftell.c
index 8053a1de2..d69202bd3 100644
--- a/lang/cem/libcc.ansi/sys/stdio/ftell.c
+++ b/lang/cem/libcc.ansi/sys/stdio/ftell.c
@@ -6,9 +6,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 long ftell(FILE* stream)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/setbuf.c b/lang/cem/libcc.ansi/sys/stdio/setbuf.c
index 5ac3e8ece..58a99ecad 100644
--- a/lang/cem/libcc.ansi/sys/stdio/setbuf.c
+++ b/lang/cem/libcc.ansi/sys/stdio/setbuf.c
@@ -4,9 +4,8 @@
 /* $Id$ */
 
 #include <stdio.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 void setbuf(register FILE* stream, char* buf)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/setvbuf.c b/lang/cem/libcc.ansi/sys/stdio/setvbuf.c
index 1dfc6a0be..439d12dd4 100644
--- a/lang/cem/libcc.ansi/sys/stdio/setvbuf.c
+++ b/lang/cem/libcc.ansi/sys/stdio/setvbuf.c
@@ -5,9 +5,8 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 int setvbuf(register FILE* stream, char* buf, int mode, size_t size)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/snprintf.c b/lang/cem/libcc.ansi/sys/stdio/snprintf.c
deleted file mode 100644
index 4ee372faa..000000000
--- a/lang/cem/libcc.ansi/sys/stdio/snprintf.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * sprintf - print formatted output on an array
- */
-/* $Id$ */
-
-#include <stdio.h>
-#include <stdarg.h>
-#include "loc_incl.h"
-
-#if ACKCONF_WANT_STDIO
-
-int snprintf(char* s, size_t len, const char* format, ...)
-{
-	va_list ap;
-	int retval;
-	FILE tmp_stream;
-
-	va_start(ap, format);
-
-	tmp_stream._fd = -1;
-	tmp_stream._flags = _IOWRITE + _IONBF + _IOWRITING;
-	tmp_stream._buf = (unsigned char*)s;
-	tmp_stream._ptr = (unsigned char*)s;
-	tmp_stream._count = len;
-
-	retval = _doprnt(format, ap, &tmp_stream);
-	putc('\0', &tmp_stream);
-
-	va_end(ap);
-
-	return retval;
-}
-
-#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/sprintf.c b/lang/cem/libcc.ansi/sys/stdio/sprintf.c
deleted file mode 100644
index 3a116c0f4..000000000
--- a/lang/cem/libcc.ansi/sys/stdio/sprintf.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * sprintf - print formatted output on an array
- */
-/* $Id$ */
-
-#include <stdio.h>
-#include <stdarg.h>
-#include "loc_incl.h"
-
-#if ACKCONF_WANT_STDIO
-
-int sprintf(char* s, const char* format, ...)
-{
-	va_list ap;
-	int retval;
-	FILE tmp_stream;
-
-	va_start(ap, format);
-
-	tmp_stream._fd = -1;
-	tmp_stream._flags = _IOWRITE + _IONBF + _IOWRITING;
-	tmp_stream._buf = (unsigned char*)s;
-	tmp_stream._ptr = (unsigned char*)s;
-	tmp_stream._count = 32767;
-
-	retval = _doprnt(format, ap, &tmp_stream);
-	putc('\0', &tmp_stream);
-
-	va_end(ap);
-
-	return retval;
-}
-
-#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/sscanf.c b/lang/cem/libcc.ansi/sys/stdio/sscanf.c
deleted file mode 100644
index bd39100bd..000000000
--- a/lang/cem/libcc.ansi/sys/stdio/sscanf.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * sscanf - read formatted output from a string
- */
-/* $Id$ */
-
-#include <stdio.h>
-#include <stdarg.h>
-#include <string.h>
-#include "loc_incl.h"
-
-#if ACKCONF_WANT_STDIO
-
-int sscanf(const char* s, const char* format, ...)
-{
-	va_list ap;
-	int retval;
-	FILE tmp_stream;
-
-	va_start(ap, format);
-
-	tmp_stream._fd = -1;
-	tmp_stream._flags = _IOREAD + _IONBF + _IOREADING;
-	tmp_stream._buf = (unsigned char*)s;
-	tmp_stream._ptr = (unsigned char*)s;
-	tmp_stream._count = strlen(s);
-
-	retval = _doscan(&tmp_stream, format, ap);
-
-	va_end(ap);
-
-	return retval;
-}
-
-#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/tmpfile.c b/lang/cem/libcc.ansi/sys/stdio/tmpfile.c
index e50fd0d35..d6aa31825 100644
--- a/lang/cem/libcc.ansi/sys/stdio/tmpfile.c
+++ b/lang/cem/libcc.ansi/sys/stdio/tmpfile.c
@@ -7,13 +7,12 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
-#include "loc_incl.h"
 
 #if ACKCONF_WANT_STDIO
 
 FILE* tmpfile(void)
 {
-	static char name_buffer[L_tmpnam] = "/tmp/tmp.";
+	static char name_buffer[L_tmpnam] = ACK_TMP_PREFIX;
 	static char* name = NULL;
 	FILE* file;
 
diff --git a/lang/cem/libcc.ansi/sys/stdio/tmpnam.c b/lang/cem/libcc.ansi/sys/stdio/tmpnam.c
index 89fb9a4e3..2f40ce716 100644
--- a/lang/cem/libcc.ansi/sys/stdio/tmpnam.c
+++ b/lang/cem/libcc.ansi/sys/stdio/tmpnam.c
@@ -7,13 +7,12 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
-#include "loc_incl.h"
 
 #if ACKCONF_WANT_STDIO
 
 char* tmpnam(char* s)
 {
-	static char name_buffer[L_tmpnam] = "/tmp/tmp.";
+	static char name_buffer[L_tmpnam] = ACK_TMP_PREFIX;
 	static unsigned long count = 0;
 	static char* name = NULL;
 
diff --git a/lang/cem/libcc.ansi/sys/stdio/ungetc.c b/lang/cem/libcc.ansi/sys/stdio/ungetc.c
index a53cc1cf9..f00447e27 100644
--- a/lang/cem/libcc.ansi/sys/stdio/ungetc.c
+++ b/lang/cem/libcc.ansi/sys/stdio/ungetc.c
@@ -4,9 +4,8 @@
 /* $Id$ */
 
 #include <stdio.h>
-#include "loc_incl.h"
 
-#if ACKCONF_WANT_STDIO
+#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
 
 int ungetc(int ch, FILE* stream)
 {
diff --git a/lang/cem/libcc.ansi/sys/stdio/vfprintf.c b/lang/cem/libcc.ansi/sys/stdio/vfprintf.c
deleted file mode 100644
index 02b473dd6..000000000
--- a/lang/cem/libcc.ansi/sys/stdio/vfprintf.c
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * vfprintf - formatted output without ellipsis
- */
-/* $Id$ */
-
-#include <stdio.h>
-#include <stdarg.h>
-#include "loc_incl.h"
-
-#if ACKCONF_WANT_STDIO
-
-int vfprintf(FILE* stream, const char* format, va_list arg)
-{
-	return _doprnt(format, arg, stream);
-}
-
-#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/vsnprintf.c b/lang/cem/libcc.ansi/sys/stdio/vsnprintf.c
deleted file mode 100644
index d973b8066..000000000
--- a/lang/cem/libcc.ansi/sys/stdio/vsnprintf.c
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * vsprintf - print formatted output without ellipsis on an array
- */
-/* $Id$ */
-
-#include <stdio.h>
-#include <stdarg.h>
-#include "loc_incl.h"
-
-#if ACKCONF_WANT_STDIO
-
-int vsnprintf(char* s, size_t len, const char* format, va_list arg)
-{
-	int retval;
-	FILE tmp_stream;
-
-	tmp_stream._fd = -1;
-	tmp_stream._flags = _IOWRITE + _IONBF + _IOWRITING;
-	tmp_stream._buf = (unsigned char*)s;
-	tmp_stream._ptr = (unsigned char*)s;
-	tmp_stream._count = len;
-
-	retval = _doprnt(format, arg, &tmp_stream);
-	putc('\0', &tmp_stream);
-
-	return retval;
-}
-
-#endif
diff --git a/lang/cem/libcc.ansi/sys/stdio/vsprintf.c b/lang/cem/libcc.ansi/sys/stdio/vsprintf.c
deleted file mode 100644
index 00065bec0..000000000
--- a/lang/cem/libcc.ansi/sys/stdio/vsprintf.c
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * vsprintf - print formatted output without ellipsis on an array
- */
-/* $Id$ */
-
-#include <stdio.h>
-#include <stdarg.h>
-#include "loc_incl.h"
-
-#if ACKCONF_WANT_STDIO
-
-int vsprintf(char* s, const char* format, va_list arg)
-{
-	int retval;
-	FILE tmp_stream;
-
-	tmp_stream._fd = -1;
-	tmp_stream._flags = _IOWRITE + _IONBF + _IOWRITING;
-	tmp_stream._buf = (unsigned char*)s;
-	tmp_stream._ptr = (unsigned char*)s;
-	tmp_stream._count = 32767;
-
-	retval = _doprnt(format, arg, &tmp_stream);
-	putc('\0', &tmp_stream);
-
-	return retval;
-}
-
-#endif
diff --git a/plat/cpm/README b/plat/cpm/README
index c7d7b1ac4..a774d0d50 100644
--- a/plat/cpm/README
+++ b/plat/cpm/README
@@ -1,26 +1,22 @@
-# $Source$
-# $State$
-# $Revision$
-
-
 The cpm platform
 =================
 
 cpm is an i80-based BSP that generates CP/M executables that can be run on any
 CP/M-compliant machine.
 
-This port only implements a very limited set of syscalls --- and most of those
-are stubs required to make the demo apps link. File descriptors 0, 1 and 2
-represent the console. Each read() blocks and reads an entire line (it can't
-read part of a line) from the CP/M line editor, then appends \n. Each write()
-converts \n to \r\n. The line editor and \n conversion can't be turned off.
+CP/M has special needs in many ways, the main one being that it doesn't
+support byte-accessible files --- only complete 128-byte sectors can be read
+or written. The port's read/write/open/close/lseek etc should handle this
+transparently, but trying to write a fragment of a sector will involve a
+read/modify/write cycle. No buffering is done (that's stdio's job).
 
-There's a special, if rather minimilist, interface to give applications access
+File descriptors 0, 1 and 2 represent the console, as usual.
+
+In addition, there's a special interface to give applications direct access
 to CP/M. See include/cpm.h for details.
 
-Link with `ack -fp` to enable software floating point. Otherwise, attempts to
-use floating-point numbers will cause the program to terminate.
-
+Floating point is not supported and attempts to use floating-point numbers
+will cause the program to terminate.
 
 Example command line
 ====================
diff --git a/plat/cpm/descr b/plat/cpm/descr
index 2dea09e10..c023fc45c 100644
--- a/plat/cpm/descr
+++ b/plat/cpm/descr
@@ -75,6 +75,8 @@ name led
 		(.ocm.bas.mod.b.c.p:{TAIL}={PLATFORMDIR}/libc.a) \
 		{FLOATS?} \
 		(.e:{TAIL}={PLATFORMDIR}/libem.a \
+		           {PLATFORMDIR}/libsys.a \
+				   {PLATFORMDIR}/libc.a \
 		           {PLATFORMDIR}/libsys.a \
 				   {PLATFORMDIR}/libem.a \
 		           {PLATFORMDIR}/libend.a)
diff --git a/plat/cpm/include/ack/file.h b/plat/cpm/include/ack/file.h
new file mode 100644
index 000000000..b60da6870
--- /dev/null
+++ b/plat/cpm/include/ack/file.h
@@ -0,0 +1,46 @@
+#ifndef ACK_FILE_H
+#define ACK_FILE_H
+
+/* CP/M custom FILE* implementation. */
+
+#define L_tmpnam 16 /* 0a:12345678.abc */
+#define ACK_TMP_PREFIX "0a:tmp"
+#define TMP_MAX 999
+
+#include <cpm.h>
+
+#define CPM_FAKE_FILE ((FILE*)1)
+#define stdin CPM_FAKE_FILE
+#define stdout CPM_FAKE_FILE
+#define stderr CPM_FAKE_FILE
+
+struct FILE
+{
+    uint8_t user;
+    FCB fcb;
+    char buffer[128];
+};
+
+#define getc(p) cpm_getc(p)
+#define putc(c, p) cpm_putc(c, p)
+#define feof(p) cpm_feof(p)
+#define ferror(p) cpm_ferror(p)
+#define clearerr(p) cpm_clearerr(p)
+
+extern int cpm_putc(int c, FILE* stream);
+extern int cpm_getc(FILE* stream);
+
+#if 0
+#define	getc(p)		(--(p)->_count >= 0 ? (int) (*(p)->_ptr++) : \
+				__fillbuf(p))
+#define	putc(c, p)	(--(p)->_count >= 0 ? \
+			 (int) (*(p)->_ptr++ = (c)) : \
+			 __flushbuf((c),(p)))
+
+#define	feof(p)		(((p)->_flags & _IOEOF) != 0)
+#define	ferror(p)	(((p)->_flags & _IOERR) != 0)
+#define clearerr(p)	((p)->_flags &= ~(_IOERR|_IOEOF))
+#endif
+
+
+#endif
diff --git a/plat/cpm/include/ack/plat.h b/plat/cpm/include/ack/plat.h
index 321dadf18..d6270fe5c 100644
--- a/plat/cpm/include/ack/plat.h
+++ b/plat/cpm/include/ack/plat.h
@@ -6,9 +6,21 @@
 #ifndef _ACK_PLAT_H
 #define _ACK_PLAT_H
 
+/* The 8080 code generator doesn't do floating point. */
+
+#define ACKCONF_WANT_STDIO_FLOAT 0
+
 /* We're providing a time() system call rather than wanting a wrapper around
  * gettimeofday() in the libc. */
  
 #define ACKCONF_WANT_EMULATED_TIME 0
 
+/* Processes? CP/M? Hahahaha... */
+
+#define ACKCONF_WANT_EMULATED_POPEN 0
+
+/* We have a very small address space, so override the default buffer size. */
+
+#define BUFSIZ 256
+
 #endif
diff --git a/plat/cpm/include/build.lua b/plat/cpm/include/build.lua
index 9820e3e09..ea35db386 100644
--- a/plat/cpm/include/build.lua
+++ b/plat/cpm/include/build.lua
@@ -9,6 +9,7 @@ local function addheader(h)
 end
 
 addheader("ack/plat.h")
+addheader("ack/file.h")
 addheader("sys/types.h")
 addheader("cpm.h")
 
diff --git a/plat/cpm/include/cpm.h b/plat/cpm/include/cpm.h
index 3ea9f6e09..3ad97b183 100644
--- a/plat/cpm/include/cpm.h
+++ b/plat/cpm/include/cpm.h
@@ -67,10 +67,19 @@ extern uint8_t* cpm_ramtop;
 extern uint8_t cpm_cmdlinelen;
 extern char cpm_cmdline[0x7f];
 
+/* Special: parses a filename into an FCB. Returns the user code (if any).
+ * Warning: cannot fail (because CP/M filespecs are incredibly lax). */
+
+extern uint8_t cpm_parse_filename(FCB* fcb, const char* filename);
+
 /* Special: if the CCP hasn't been overwritten, returns to it; otherwise does
  * a warmboot. */
 extern void cpm_exit(void);
 
+/* Special: equivalent to cpm_read_random() except if you read unwritten data
+ * 0 is returned (and the buffer contains garbage). */
+extern uint8_t cpm_read_random_safe(FCB* fcb);
+
 /* Extends cpm_ramtop over the CCP, for a little extra space. */
 extern void cpm_overwrite_ccp(void);
 
@@ -114,4 +123,7 @@ extern void cpm_overwrite_ccp(void);
 /* 37 */ extern uint8_t cpm_reset_drives(uint16_t drive_bitmap);
 /* 40 */ extern uint8_t cpm_write_random_filled(FCB* fcb);
 
+#define cpm_get_user() cpm_get_set_user(0xff)
+#define cpm_set_user(u) cpm_get_set_user(u)
+
 #endif
diff --git a/plat/cpm/libsys/build.lua b/plat/cpm/libsys/build.lua
index 9091a6917..070290326 100644
--- a/plat/cpm/libsys/build.lua
+++ b/plat/cpm/libsys/build.lua
@@ -47,28 +47,28 @@ local bdos_calls = {
 
 local trap_calls = {
     "EARRAY",
+    "EBADGTO",
+    "EBADLAE",
+    "EBADLIN",
+    "EBADMON",
+    "EBADPC",
+    "EBADPTR",
+    "ECASE",
+    "ECONV",
+    "EFDIVZ",
+    "EFOVFL",
+    "EFUND",
+    "EFUNFL",
+    "EHEAP",
+    "EIDIVZ",
+    "EILLINS",
+    "EIOVFL",
+    "EIUND",
+    "EMEMFLT",
+    "EODDZ",
     "ERANGE",
     "ESET",
-    "EIOVFL",
-    "EFOVFL",
-    "EFUNFL",
-    "EIDIVZ",
-    "EFDIVZ",
-    "EIUND",
-    "EFUND",
-    "ECONV",
     "ESTACK",
-    "EHEAP",
-    "EILLINS",
-    "EODDZ",
-    "ECASE",
-    "EMEMFLT",
-    "EBADPTR",
-    "EBADPC",
-    "EBADLAE",
-    "EBADMON",
-    "EBADLIN",
-    "EBADGTO",
     "EUNIMPL",
 }
 
diff --git a/plat/cpm/libsys/close.c b/plat/cpm/libsys/close.c
index 1c570029b..be5ae0ec4 100644
--- a/plat/cpm/libsys/close.c
+++ b/plat/cpm/libsys/close.c
@@ -1,14 +1,31 @@
-/* $Source$
- * $State$
- * $Revision$
- */
-
 #include <stdlib.h>
 #include <errno.h>
 #include <unistd.h>
+#include <cpm.h>
+#include "cpmsys.h"
 
 int close(int fd)
 {
-	errno = EBADF;
-	return -1;
+    struct FCBE* fcbe = &__fd[fd];
+    int result = 0;
+    uint8_t olduser;
+
+    __init_file_descriptors();
+    if (fcbe->fcb.f[0])
+    {
+        /* There's an actual filename here, so assume it's an open file. */
+
+        olduser = cpm_get_user();
+        cpm_set_user(fcbe->user);
+        if (cpm_close_file(&fcbe->fcb) == 0xff)
+        {
+            errno = EIO;
+            result = -1;
+        }
+        cpm_set_user(olduser);
+    }
+
+    memset(fcbe, 0, sizeof(struct FCBE));
+    return result;
 }
+
diff --git a/plat/cpm/libsys/cpm_read_random_safe.c b/plat/cpm/libsys/cpm_read_random_safe.c
new file mode 100644
index 000000000..1c5838bd6
--- /dev/null
+++ b/plat/cpm/libsys/cpm_read_random_safe.c
@@ -0,0 +1,10 @@
+#include <string.h>
+#include <cpm.h>
+
+uint8_t cpm_read_random_safe(FCB* fcb)
+{
+    uint8_t r = cpm_read_random(fcb);
+    if ((r == 1) || (r == 4))
+        r = 0;
+    return r;
+}
diff --git a/plat/cpm/libsys/cpmsys.h b/plat/cpm/libsys/cpmsys.h
new file mode 100644
index 000000000..d659f9e9f
--- /dev/null
+++ b/plat/cpm/libsys/cpmsys.h
@@ -0,0 +1,22 @@
+#ifndef CPMSYS_H
+#define CPMSYS_H
+
+/* File descriptor emulation */
+
+struct FCBE
+{
+    uint16_t length; /* number of records */
+    FCB fcb; /* drive 0 means the console, f[0] == 0 means unallocated */
+    uint8_t user;
+    uint8_t offset; /* into current sector */
+};
+
+#define NUM_FILE_DESCRIPTORS 8
+extern struct FCBE __fd[NUM_FILE_DESCRIPTORS];
+extern uint8_t __transfer_buffer[128];
+
+extern void __init_file_descriptors(void);
+
+#define SECTOR_ALIGNED(s) (((s) & 0x7f) == 0)
+
+#endif
diff --git a/plat/cpm/libsys/fcb.c b/plat/cpm/libsys/fcb.c
new file mode 100644
index 000000000..96705c467
--- /dev/null
+++ b/plat/cpm/libsys/fcb.c
@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <cpm.h>
+#include <string.h>
+#include <ctype.h>
+#include "cpmsys.h"
+
+static const char* fill(uint8_t* dest, const char* src, int len)
+{
+    do
+    {
+        char c = toupper(*src);
+        if (!c || (c == '.'))
+            c = ' ';
+        else if (c == '*')
+            c = '?';
+        else
+            src++;
+        *dest++ = c;
+    }
+    while (--len);
+    return src;
+}
+
+uint8_t cpm_parse_filename(FCB* fcb, const char* filename)
+{
+    uint8_t user = cpm_get_user();
+    char c;
+
+    memset(fcb, 0, sizeof(FCB));
+    memset(fcb->f, ' ', sizeof(fcb->f));
+
+    {
+        const char* colon = strchr(filename, ':');
+        if (colon)
+        {
+            c = *filename++;
+            if (isdigit(c))
+            {
+                user = strtol(filename-1, &filename, 10);
+                c = *filename++;
+            }
+            c = toupper(c);
+            if (isalpha(c))
+            {
+                fcb->dr = c - '@';
+                c = *filename++;
+            }
+
+            filename = colon + 1;
+        }
+    }
+
+    /* Read filename part. */
+
+    filename = fill(&fcb->f[0], filename, 8);
+    filename = strchr(filename, '.');
+    if (filename)
+        fill(&fcb->f[8], filename+1, 3);
+
+    if (fcb->dr == 0)
+        fcb->dr = cpm_get_current_drive() + 1;
+    return user;
+}
+
diff --git a/plat/cpm/libsys/fd.c b/plat/cpm/libsys/fd.c
new file mode 100644
index 000000000..e98c9d7b2
--- /dev/null
+++ b/plat/cpm/libsys/fd.c
@@ -0,0 +1,19 @@
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <cpm.h>
+#include "cpmsys.h"
+
+struct FCBE __fd[NUM_FILE_DESCRIPTORS];
+uint8_t __transfer_buffer[128];
+
+void __init_file_descriptors(void)
+{
+    static uint8_t initialised = 0;
+    if (!initialised)
+    {
+        /* Mark stdin, stdout, stderr as being open files. */
+        __fd[0].fcb.f[0] = __fd[1].fcb.f[0] = __fd[2].fcb.f[0] = ' ';
+        initialised = 1;
+    }
+}
diff --git a/plat/cpm/libsys/lseek.c b/plat/cpm/libsys/lseek.c
index ecbc4b520..9b8648b52 100644
--- a/plat/cpm/libsys/lseek.c
+++ b/plat/cpm/libsys/lseek.c
@@ -1,14 +1,28 @@
-/* $Source$
- * $State$
- * $Revision$
- */
-
+#include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <sys/types.h>
 #include <unistd.h>
+#include <cpm.h>
+#include "cpmsys.h"
 
 off_t lseek(int fd, off_t offset, int whence)
 {
-	errno = EINVAL;
-	return -1;
+    struct FCBE* fcbe = &__fd[fd];
+
+    __init_file_descriptors();
+    if (fcbe->fcb.dr == 0)
+    {
+        /* Can't seek the console. */
+        return 0;
+    }
+
+    if (whence == SEEK_END)
+        offset += fcbe->length<<7;
+    if (whence == SEEK_CUR)
+        offset += (U16(fcbe->fcb.r)<<7) | fcbe->offset;
+    
+    U16(fcbe->fcb.r) = offset>>7;
+    fcbe->offset = offset & 0x7f;
+    return offset;
 }
diff --git a/plat/cpm/libsys/open.c b/plat/cpm/libsys/open.c
index f3522eae5..82345fb55 100644
--- a/plat/cpm/libsys/open.c
+++ b/plat/cpm/libsys/open.c
@@ -1,14 +1,61 @@
-/* $Source$
- * $State$
- * $Revision$
- */
-
+#include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <unistd.h>
+#include <cpm.h>
+#include "cpmsys.h"
 
 int open(const char* path, int access, ...)
 {
-	errno = EACCES;
+	uint8_t fd = 0;
+    struct FCBE* fcbe = &__fd[0];
+	uint8_t olduser;
+	
+    __init_file_descriptors();
+	while (fd != NUM_FILE_DESCRIPTORS)
+	{
+		if (fcbe->fcb.f[0] == 0)
+			break;
+		fd++;
+		fcbe++;
+	}
+	if (fd == NUM_FILE_DESCRIPTORS)
+	{
+		errno = EMFILE;
+		return -1;
+	}
+
+	fcbe->user = cpm_parse_filename(&fcbe->fcb, path);
+
+	olduser = cpm_get_user();
+	cpm_set_user(fcbe->user);
+
+	if (access & O_TRUNC)
+	{
+		cpm_delete_file(&fcbe->fcb);
+		access |= O_CREAT;
+	}
+	if (access & O_CREAT)
+	{
+		if (cpm_make_file(&fcbe->fcb) == 0xff)
+			goto eio;
+	}
+	else
+	{
+		if (cpm_open_file(&fcbe->fcb) == 0xff)
+			goto eio;
+	}
+
+	cpm_seek_to_end(&fcbe->fcb);
+	fcbe->length = U16(fcbe->fcb.r);
+	if (!(access & O_APPEND))
+		U16(fcbe->fcb.r) = 0;
+	return fd;
+
+eio:
+	fcbe->fcb.f[0] = 0;
+	errno = EIO;
 	return -1;
 }
+
+
diff --git a/plat/cpm/libsys/read.c b/plat/cpm/libsys/read.c
index b04a13ee5..c2a1abd61 100644
--- a/plat/cpm/libsys/read.c
+++ b/plat/cpm/libsys/read.c
@@ -3,47 +3,109 @@
  * $Revision$
  */
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <unistd.h>
+#include <string.h>
 #include <cpm.h>
+#include "cpmsys.h"
 
 ssize_t read(int fd, void* buffer, size_t count)
 {
-	short save;
-	unsigned char before_n;
+	uint8_t* bbuffer = buffer;
+	struct FCBE* fcbe = &__fd[fd];
+	uint8_t olduser;
+	ssize_t result;
+	uint8_t* src;
 
-	/* We're only allowed to read from fd 0, 1 or 2. */
-	if ((fd < 0) || (fd > 2))
+    __init_file_descriptors();
+	if (fcbe->fcb.dr == 0)
 	{
-		errno = EBADF;
-		return -1;
+		/* Read from the console. */
+
+		if (count == 0)
+			return 0;
+		*(uint8_t*)buffer = cpm_conin();
+		return 1;
 	}
 
-	/* We need room for at least 1 char plus '\n'. */
-	if (count < 2)
+	olduser = cpm_get_user();
+	cpm_set_user(fcbe->user);
+
+	if (U16(fcbe->fcb.r) >= fcbe->length)
+		goto done;
+	if (fcbe->offset || !SECTOR_ALIGNED(count))
 	{
-		errno = EINVAL;
-		return -1;
+		/* We need to read bytes until we're at a sector boundary. */
+
+		cpm_set_dma(__transfer_buffer);
+		if (cpm_read_random_safe(&fcbe->fcb) != 0)
+			goto eio;
+
+		/* Copy enough bytes to reach the end of the sector. */
+
+		src = __transfer_buffer + fcbe->offset;
+		while ((count != 0) && (fcbe->offset != 128))
+		{
+			*bbuffer++ = *src++;
+			fcbe->offset++;
+			count--;
+		}
+
+		/* If we've read enough bytes, advance to the next sector. */
+
+		if (fcbe->offset == 128)
+		{
+			U16(fcbe->fcb.r)++;
+			fcbe->offset = 0;
+		}
 	}
 
-	/* Make room to append '\n' later. */
-	before_n = count > 255 ? 255 : count - 1;
+	while (count >= 128)
+	{
+		if (U16(fcbe->fcb.r) >= fcbe->length)
+			goto done;
 
-	/* Borrow 2 bytes of RAM before the buffer. */
-	/* This might overwrite count!!! */
-	save = ((short*)buffer)[-1];
+		/* Read entire sectors directly into the destination buffer. */
 
-	/* Read one line from the console. */
-	((unsigned char*)buffer)[-2] = before_n;
-	cpm_readline((uint8_t*)buffer - 2);
-	before_n = ((unsigned char*)buffer)[-1];
+		cpm_set_dma(bbuffer);
+		if (cpm_read_random_safe(&fcbe->fcb) != 0)
+			goto eio;
+		count -= 128;
+		bbuffer += 128;
+		U16(fcbe->fcb.r)++;
+	}
 
-	((char*)buffer)[before_n] = '\n'; /* Append '\n'. */
-	((short*)buffer)[-1] = save; /* Give back borrowed bytes. */
+	if (count != 0)
+	{
+		if (U16(fcbe->fcb.r) >= fcbe->length)
+			goto done;
 
-	/* Echo '\n' to console. */
-	cpm_printstring("\r\n$");
+		/* There's some trailing data to read. */
 
-	return (int)before_n + 1;
+		cpm_set_dma(__transfer_buffer);
+		if (cpm_read_random_safe(&fcbe->fcb) != 0)
+			goto eio;
+
+		src = __transfer_buffer;
+		while (count != 0)
+		{
+			*bbuffer++ = *src++;
+			count--;
+		}
+
+		fcbe->offset = count;
+	}
+
+done:
+	result = bbuffer - (uint8_t*)buffer;
+exit:
+	cpm_set_user(olduser);
+	return result;
+
+eio:
+	errno = EIO;
+	result = -1;
+	goto exit;
 }
diff --git a/plat/cpm/libsys/write.c b/plat/cpm/libsys/write.c
index 768e9b2eb..eb2c89a0a 100644
--- a/plat/cpm/libsys/write.c
+++ b/plat/cpm/libsys/write.c
@@ -6,7 +6,9 @@
 #include <stdlib.h>
 #include <errno.h>
 #include <unistd.h>
+#include <string.h>
 #include <cpm.h>
+#include "cpmsys.h"
 
 void _sys_write_tty(char c)
 {
@@ -17,24 +19,107 @@ void _sys_write_tty(char c)
 
 ssize_t write(int fd, void* buffer, size_t count)
 {
-	int i;
-	char* p = buffer;
-	
-	/* We're only allowed to write to fd 0, 1 or 2. */
-	
-	if ((fd < 0) || (fd > 2))
+	const uint8_t* bbuffer = buffer;
+	struct FCBE* fcbe = &__fd[fd];
+	uint8_t olduser;
+	uint16_t result;
+	uint8_t* dest;
+
+    __init_file_descriptors();
+	if (fcbe->fcb.dr == 0)
 	{
-		errno = EBADF;
-		return -1;
+		/* Write to the console. */
+
+		size_t i = count;
+		while (i--)
+			_sys_write_tty(*bbuffer++);
+		return count;
 	}
-	
-	/* Write all data. */
-	
-	i = count;
-	while (i--)
-		_sys_write_tty(*p++);
-	
-	/* No failures. */
-	
-	return count;
+
+	olduser = cpm_get_user();
+	cpm_set_user(fcbe->user);
+
+	if (fcbe->offset || !SECTOR_ALIGNED(count))
+	{
+		/* We're not at a sector boundary, so we need to do a
+		 * read/modify/write of the initial fragment. */
+
+		cpm_set_dma(__transfer_buffer);
+		if (cpm_read_random_safe(&fcbe->fcb) != 0)
+			goto eio;
+
+		/* Copy enough bytes to reach the end of the sector. */
+
+		dest = __transfer_buffer + fcbe->offset;
+		while ((count != 0) && (fcbe->offset != 128))
+		{
+			*dest++ = *bbuffer++;
+			fcbe->offset++;
+			count--;
+		}
+
+		/* Write back. */
+
+		if (cpm_write_random(&fcbe->fcb) != 0)
+			goto eio;
+
+		/* If we've written enough bytes, advance to the next sector. */
+
+		if (fcbe->offset == 128)
+		{
+			U16(fcbe->fcb.r)++;
+			fcbe->offset = 0;
+		}
+	}
+
+	while (count >= 128)
+	{
+		/* Write entire sectors directly from the source buffer. */
+
+		cpm_set_dma(bbuffer);
+		if (cpm_write_random(&fcbe->fcb) != 0)
+			goto eio;
+		count -= 128;
+		bbuffer += 128;
+		U16(fcbe->fcb.r)++;
+	}
+
+	if (count != 0)
+	{
+		/* There's some trailing data to write. We need another
+		 * read/modify/write cycle. */
+
+		cpm_set_dma(__transfer_buffer);
+		if (cpm_read_random_safe(&fcbe->fcb) != 0)
+			goto eio;
+
+		dest = __transfer_buffer;
+		while (count != 0)
+		{
+			*dest++ = *bbuffer++;
+			count--;
+		}
+
+		if (cpm_write_random(&fcbe->fcb) != 0)
+			goto eio;
+
+		fcbe->offset = count;
+	}
+
+	if (U16(fcbe->fcb.r) >= fcbe->length)
+	{
+		fcbe->length = U16(fcbe->fcb.r);
+		if (fcbe->offset != 0)
+			fcbe->length++;
+	}
+
+	result = bbuffer - (uint8_t*)buffer;
+exit:
+	cpm_set_user(olduser);
+	return result;
+
+eio:
+	errno = EIO;
+	result = -1;
+	goto exit;
 }
diff --git a/plat/cpm/tests/build.lua b/plat/cpm/tests/build.lua
index 6518c6849..1a8488136 100644
--- a/plat/cpm/tests/build.lua
+++ b/plat/cpm/tests/build.lua
@@ -4,5 +4,6 @@ plat_testsuite {
     name = "tests",
     plat = "cpm",
     method = "plat/cpm/emu+emu",
-	skipsets = {"floats"},
+    skipsets = {"floats"},
+    tests = { "./*.c" },
 }
diff --git a/plat/cpm/tests/parsefcb_c.c b/plat/cpm/tests/parsefcb_c.c
new file mode 100644
index 000000000..53605e2a4
--- /dev/null
+++ b/plat/cpm/tests/parsefcb_c.c
@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <cpm.h>
+#include "test.h"
+
+struct testcase
+{
+    const char* input;
+    uint8_t drive;
+    uint8_t user;
+    const char filename[11];
+};
+
+struct testcase tests[] =
+{
+    { "12345678.ABC", 'A', 0,  "12345678ABC" },
+    { "12345678.A",   'A', 0,  "12345678A  " },
+    { "12345678",     'A', 0,  "12345678   " },
+    { "1",            'A', 0,  "1          " },
+    { ".X",           'A', 0,  "        X  " },
+
+    { "B:FOO",        'B', 0,  "FOO        " },
+    { "Z:FOO",        'Z', 0,  "FOO        " },
+    { "1Z:FOO",       'Z', 1,  "FOO        " },
+    { "23Z:FOO",      'Z', 23, "FOO        " },
+
+    { "*.*",          'A', 0,  "???????????" },
+    { "FOO*.*",       'A', 0,  "FOO????????" },
+    { "FOO*",         'A', 0,  "FOO?????   " },
+    { "FOO.*",        'A', 0,  "FOO     ???" },
+};
+
+static int failed = 0;
+
+static void do_test(int i, struct testcase* test)
+{
+    static FCB fcb;
+    uint8_t got_user = cpm_parse_filename(&fcb, test->input);
+
+    if ((got_user == test->user)
+        && (fcb.dr == (test->drive - '@'))
+        && (memcmp(fcb.f, test->filename, 11) == 0))
+        return;
+
+    printf("Want: %s -> %d%c:'%.11s' but got %d%c:'%.11s'\n",
+        test->input,
+        test->user, test->drive, test->filename,
+        got_user, fcb.dr+'@', fcb.f);
+
+    failed = 1;
+}
+
+int main(int argc, const char* argv[])
+{
+    int i;
+
+    failed = 0;
+    cpm_select_drive(0); /* A: */
+    cpm_set_user(0);
+
+    for (i=0; i<sizeof(tests)/sizeof(*tests); i++)
+        do_test(i, &tests[i]);
+
+    if (failed)
+        fail(0);
+    finished();
+}
diff --git a/tests/plat/build.lua b/tests/plat/build.lua
index c35bd2d96..f7eecc0dd 100644
--- a/tests/plat/build.lua
+++ b/tests/plat/build.lua
@@ -6,11 +6,12 @@ definerule("plat_testsuite",
 		method = { type="string" },
 		sets = { type="table", default={"core", "b", "bugs", "m2", "floats"}},
 		skipsets = { type="table", default={}},
+		tests = { type="targets", default={} },
 	},
 	function(e)
 		-- Remember this is executed from the caller's directory; local
 		-- target names will resolve there.
-		local testfiles = {}
+		local testfiles = filenamesof(e.tests)
 		local skipsets = {}
 		for _, set in ipairs(e.skipsets) do
 			skipsets[set] = true