diff --git a/BaS_gcc/sources/usb_mem.c b/BaS_gcc/sources/usb_mem.c
new file mode 100644
index 0000000..4ffa056
--- /dev/null
+++ b/BaS_gcc/sources/usb_mem.c
@@ -0,0 +1,279 @@
+/*
+ *	usb_mem.c
+ *
+ * based from Emutos / BDOS
+ * 
+ * Copyright (c) 2001 Lineo, Inc.
+ *
+ * Authors: Karl T. Braun, Martin Doering, Laurent Vogel
+ *
+ * This file is distributed under the GPL, version 2 or at your
+ * option any later version.
+ */
+
+#include <stdint.h>
+#include "bas_string.h"
+#include "bas_printf.h"
+#include "usb.h"
+#if MACHINE_FIREBEE
+#include "firebee.h"
+#elif MACHINE_M5484LITE
+#include "m5484l.h"
+#endif
+
+#ifndef FALSE
+#define FALSE 0
+#endif
+#ifndef TRUE
+#define TRUE 1
+#endif
+
+#undef USB_MEM_DEBUG
+
+#ifdef	USB_MEM_DEBUG
+#define	USB_MEM_PRINTF(fmt,args...)	xprintf(fmt ,##args)
+#else
+#define USB_MEM_PRINTF(fmt,args...)
+#endif
+
+extern int asm_set_ipl(int level);
+extern void *info_fvdi;
+extern long offscren_reserved(void);
+
+extern uint8_t usb_buffer[];	/* defined in linker control file */
+
+/* MD - Memory Descriptor */
+
+#define MD struct _md_
+
+MD
+{
+	MD *m_link;
+	long m_start;
+	long m_length;
+  void *m_own;
+};
+
+/* MPB - Memory Partition Block */
+
+#define MPB struct _mpb
+
+MPB
+{
+	MD *mp_mfl;
+	MD *mp_mal;
+	MD *mp_rover;
+};
+
+#define MAXMD 256
+
+static MD tab_md[MAXMD];
+static MPB pmd;
+
+static void *xmgetblk(void)
+{
+	int i;
+	for(i = 0; i < MAXMD; i++)
+	{
+		if(tab_md[i].m_own == NULL)
+		{
+			tab_md[i].m_own = (void*)1L;
+			return(&tab_md[i]);
+		}
+	}			   
+	return(NULL);
+}
+
+static void xmfreblk(void *m)
+{
+	int i = (int)(((long)m - (long)tab_md) / sizeof(MD));
+	if((i > 0) && (i < MAXMD))
+		tab_md[i].m_own = NULL;
+}
+
+static MD *ffit(long amount, MPB *mp)
+{
+	MD *p,*q,*p1;                    /* free list is composed of MD's */
+	int maxflg;
+	long maxval;
+	if(amount != -1)
+	{
+		amount += 15;                  /* 16 bytes alignment */
+		amount &= 0xFFFFFFF0;
+	}
+	if((q = mp->mp_rover) == 0)      /* get rotating pointer */
+		return(0) ;
+	maxval = 0;
+	maxflg = ((amount == -1) ? TRUE : FALSE) ;
+	p = q->m_link;                   /* start with next MD */
+	do /* search the list for an MD with enough space */
+	{
+		if(p == 0)
+		{
+			/*  at end of list, wrap back to start  */
+			q = (MD *) &mp->mp_mfl;      /*  q => mfl field  */
+			p = q->m_link;               /*  p => 1st MD     */
+		}
+		if((!maxflg) && (p->m_length >= amount))
+		{
+			/*  big enough */
+			if(p->m_length == amount)
+				q->m_link = p->m_link;     /* take the whole thing */
+			else
+			{
+				/* break it up - 1st allocate a new
+				   MD to describe the remainder */
+				p1 = xmgetblk();
+				if(p1 == NULL)
+					return(NULL);
+				/* init new MD */
+				p1->m_length = p->m_length - amount;
+				p1->m_start = p->m_start + amount;
+				p1->m_link = p->m_link;
+				p->m_length = amount;      /* adjust allocated block */
+				q->m_link = p1;
+			}
+			/* link allocate block into allocated list,
+			    mark owner of block, & adjust rover  */
+			p->m_link = mp->mp_mal;
+			mp->mp_mal = p;
+			mp->mp_rover = (q == (MD *) &mp->mp_mfl ? q->m_link : q);
+			return(p);                   /* got some */
+		}
+		else if(p->m_length > maxval)
+			maxval = p->m_length;
+		p = ( q=p )->m_link;
+	}
+	while(q != mp->mp_rover);
+	/*  return either the max, or 0 (error)  */
+	if(maxflg)
+	{
+		maxval -= 15; /* 16 bytes alignment */
+		if(maxval < 0)
+			maxval = 0;
+		else
+			maxval &= 0xFFFFFFF0;
+	}
+	return(maxflg ? (MD *) maxval : 0);
+}
+
+static void freeit(MD *m, MPB *mp)
+{
+	MD *p, *q;
+	q = 0;
+	for(p = mp->mp_mfl; p ; p = (q=p) -> m_link)
+	{
+		if(m->m_start <= p->m_start)
+			break;
+	}
+	m->m_link = p;
+	if(q)
+		q->m_link = m;
+	else
+		mp->mp_mfl = m;
+	if(!mp->mp_rover)
+		mp->mp_rover = m;
+	if(p)
+	{
+		if(m->m_start + m->m_length == p->m_start)
+		{ /* join to higher neighbor */
+			m->m_length += p->m_length;
+			m->m_link = p->m_link;
+			if(p == mp->mp_rover)
+				mp->mp_rover = m;
+			xmfreblk(p);
+		}
+	}
+	if(q)
+	{
+		if(q->m_start + q->m_length == m->m_start)
+		{ /* join to lower neighbor */
+			q->m_length += m->m_length;
+			q->m_link = m->m_link;
+			if(m == mp->mp_rover)
+				mp->mp_rover = q;
+			xmfreblk(m);
+		}
+	}
+}
+
+int usb_free(void *addr)
+{
+	int level;
+	MD *p, **q;
+	MPB *mpb;
+	mpb = &pmd;
+	level = asm_set_ipl(7);
+	for(p = *(q = &mpb->mp_mal); p; p = *(q = &p->m_link))
+	{
+		if((long)addr == p->m_start)
+			break;
+	}
+	if(!p)
+	{
+		asm_set_ipl(level);
+		return(-1);
+	}
+	*q = p->m_link;
+	freeit(p, mpb);
+	asm_set_ipl(level);
+	USB_MEM_PRINTF("usb_free(0x%08X)\r\n", addr);
+	return(0);
+}
+
+void *usb_malloc(long amount)
+{
+	void *ret = NULL;
+	int level;
+	MD *m;
+	if(amount == -1L)
+		return((void *)ffit(-1L,&pmd));
+	if(amount <= 0 )
+		return(0);
+	if((amount & 1))
+		amount++;
+	level = asm_set_ipl(7);
+	m = ffit(amount, &pmd);
+	if(m != NULL)
+		ret = (void *)m->m_start;
+	asm_set_ipl(level);
+	USB_MEM_PRINTF("usb_malloc(%d) = 0x%08X\r\n", amount, ret);
+	return(ret);
+}
+
+
+
+int usb_mem_init(void)
+{
+#ifdef USE_RADEON_MEMORY
+	usb_buffer = (void *)offscren_reserved();
+	if(usb_buffer == NULL)
+#else
+#endif
+	memset(usb_buffer, 0, USB_BUFFER_SIZE);
+
+	if (usb_buffer == NULL)
+		return(-1);
+	pmd.mp_mfl = pmd.mp_rover = &tab_md[0];
+	tab_md[0].m_link = (MD *)NULL;
+	tab_md[0].m_start = ((long)usb_buffer + 15) & ~15;
+	tab_md[0].m_length = USB_BUFFER_SIZE;	
+	tab_md[0].m_own = (void *)1L;
+	pmd.mp_mal = (MD *)NULL;
+	memset(usb_buffer, 0, tab_md[0].m_length);
+	USB_MEM_PRINTF("USB malloc buffer at 0x%08X size %d\r\n", tab_md[0].m_start, tab_md[0].m_length);
+	return(0);
+}
+
+void usb_mem_stop(void)
+{
+#ifndef CONFIG_USB_MEM_NO_CACHE
+#ifdef USE_RADEON_MEMORY
+	if(usb_buffer == (void *)offscren_reserved())
+		return;
+#endif
+#endif
+}
+
+
+