Started cputc and related functions implementation.

libsrc/c1p/cputc.c

@@ -0,0 +1,71 @@
+/*
+ * cputc.c
+ *
+ * void __fastcall__ cputcxy (unsigned char x, unsigned char y, char c);
+ * void __fastcall__ cputc (char c);
+ */
+
+#include <conio.h>
+
+/* Implements a 25 by 25 screen in the 1024 bytes video ram (32 by 32) */
+#define LINEWIDTH 0x20
+#define SCREENBASE ((char *) 0xd000)
+#define TOP_OFFSET 4
+#define LEFT_OFFSET 3
+#define SCREENVISBASE (SCREENBASE + 4 * LINEWIDTH + LEFT_OFFSET)
+#define WIDTH 25
+#define HEIGHT 25
+
+static unsigned char xpos = 0;
+static unsigned char ypos = 0;
+
+void __fastcall__ cputc(char c)
+{
+    char * const cp = SCREENVISBASE + ypos * LINEWIDTH + xpos;
+
+    *cp = c;
+
+    xpos += 1;
+    if (xpos > WIDTH - 1) {
+        xpos = 0;
+        ypos += 1;
+
+        if (ypos > HEIGHT - 1) {
+            ypos = 0;
+        }
+    }
+}
+
+void __fastcall__ cputcxy (unsigned char x, unsigned char y, char c)
+{
+    xpos = x > WIDTH - 1 ? WIDTH - 1 : x;
+    ypos = y > HEIGHT - 1 ? HEIGHT - 1 : y;
+
+    cputc(c);
+}
+
+unsigned char wherex (void)
+{
+    return xpos;
+}
+
+unsigned char wherey (void)
+{
+    return ypos;
+}
+
+void __fastcall__ gotox (unsigned char x)
+{
+    xpos = x;
+}
+
+void __fastcall__ gotoy (unsigned char y)
+{
+    ypos = y;
+}
+
+void __fastcall__ gotoxy (unsigned char x, unsigned char y)
+{
+    xpos = x;
+    ypos = y;
+}