Diff: module.h

Revision:

0:806c2f2a7d47

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/module.h	Wed Jun 29 14:25:56 2011 +0000
@@ -0,0 +1,99 @@
+// -------------------------------------------------------------
+// BBC Basic hardware emulation part
+// -------------------------------------------------------------
+
+#include "bbc_0100.h"
+
+#include "mbed.h"
+#define byte unsigned char
+#define word unsigned short
+
+// some defaults
+#define ESCFLG  0xff80          // escape flag
+#define FAULT   0xff82          // fault address
+#define DEFERR  0xff84          // default error handler
+#define CMDPTR  0xff86          // command line tail
+#define SCRATCHPAD  0xff88      // Basic scratchpad area
+#define RESERVED    0xff9a      
+#define OSRDRM  0xffb9          // read byte in paged ROM
+#define MAINVDU 0xffbc          // main VDU character output entry point
+#define OSEVEN  0xffbf          // generate an event
+#define GSINIT  0xffc2          // general string input initialise routine
+#define GSREAD  0xffc5          // read character from string input
+#define UKCMD   0xffc9          // unknown command
+#define OSFSC   0xffcb          // filing system control
+#define OSFIND  0xffce          // open or close a file
+#define OSGBPB  0xffd1          // multiple byte access
+#define OSBPUT  0xffd4          // put a byte to a file
+#define OSBGET  0xffd7          // get a byte from a file
+#define OSARGS  0xffda          // read or set file arguments
+#define OSFILE  0xffdd          // load or save a file
+#define OSRDCH  0xffe0          // input a character
+#define OSASCI  0xffe3          // print a character with CR converted to LF, CR
+#define OSNEWL  0xffe7          // print a LF, CR sequence
+#define OSWRCH  0xffee          // print a character
+#define OSWORD  0xfff1          // do an OSWORD call
+#define OSBYTE  0xfff4          // do an OSBYTE call
+#define OSCLI   0xfff7          // interpret a command
+#define BRKV    0xfffa          // FAULT vector
+
+// default CP/M ram pages
+#define RAMSIZE (word)0x4000    // 16K ram
+#define RAMSTART 0x34ee
+#define RAMEND   RAMSTART+RAMSIZE
+#define PAGE     0x3800
+
+// the emulated ram space
+volatile unsigned char ram[RAMSIZE];
+
+// ramtop space with vectors
+volatile unsigned char ramtop[0x80];
+
+
+// read from memory space
+unsigned char rdmem(word addr) {
+    extern volatile unsigned short pc;
+ 
+     // all rom space
+    if (addr<RAMSTART) {
+        return rom[addr];
+    }
+
+    // ramtop with vectors
+    if ((addr >=0xff80) && (addr <=0xffff)) {
+        return ramtop[addr-0xff80];
+    }
+
+    // relocate $3400
+    if ((addr >= RAMSTART) && (addr < RAMEND)) {
+        return ram[addr-0x34ee];
+    }
+    return 0xff;   // non existant memory reads as 0xff
+}
+
+// write to memory space
+void wrmem (word addr, byte val) {
+    extern volatile unsigned short pc;
+
+    // memtop vector space
+    if ((addr >=0xff80) && (addr <=0xffff)) {
+        ramtop[addr-0xff80]=val;
+        return;
+    }
+    // printf("MEMW %04x %02x\n\r",addr,val);
+    if ((addr >= RAMSTART) && (addr < RAMEND)) {
+        ram[addr-RAMSTART] = val;
+    } 
+}
+
+// write a byte to IO space
+void out(unsigned char addr, unsigned char val) {
+    printf("IO out called %02d, %02d\n\r",addr,val);
+}
+
+// read a byte from IO space
+unsigned char in(unsigned char addr) {
+    printf("IO in called %02d\n\r",addr);
+    return 0xff;
+}
+