--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lcdemu/process.c	Wed Mar 14 18:16:45 2018 +0000
@@ -0,0 +1,108 @@
+/*
+ * Processing of LCD output (input to us)
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <strings.h>
+#include <X11/Xlib.h>
+#include <X11/Xresource.h>
+#include <X11/Xutil.h>
+#include "globals.h"
+
+#define	MAX_WIDTH	176
+
+static unsigned
+hexdecode(str)
+	char *str;
+{
+	unsigned accum = 0;
+	int i, c, n;
+
+	for (i = 0; i < 4; i++) {
+		c = str[i];
+		if (isdigit(c))
+			n = c - '0';
+		else if (isupper(c))
+			n = c - 'A' + 10;
+		else
+			n = c - 'a' + 10;
+		accum <<= 4;
+		accum |= n;
+	}
+	return(accum);
+}
+
+process_input_line(line)
+	char *line;
+{
+	int blitrow, blitcol, npix;
+	uint16_t pix16[MAX_WIDTH];
+	char *cp;
+	XImage *xi;
+
+	for (cp = line; isspace(*cp); cp++)
+		;
+	if (!isdigit(*cp)) {
+inv:		fprintf(stderr, "fc-lcdemu: invalid input line\n");
+		exit(1);
+	}
+	blitrow = atoi(cp);
+	while (isdigit(*cp))
+		cp++;
+	if (!isspace(*cp))
+		goto inv;
+	while (isspace(*cp))
+		cp++;
+	if (!isdigit(*cp))
+		goto inv;
+	blitcol = atoi(cp);
+	while (isdigit(*cp))
+		cp++;
+	if (!isspace(*cp))
+		goto inv;
+	while (isspace(*cp))
+		cp++;
+	if (!isxdigit(*cp))
+		goto inv;
+	for (npix = 0; *cp; ) {
+		if (!isxdigit(cp[0]) || !isxdigit(cp[1]) ||
+		    !isxdigit(cp[2]) || !isxdigit(cp[3]))
+			goto inv;
+		if (npix >= MAX_WIDTH) {
+			fprintf(stderr,
+		"fc-lcdemu error: input line exceeds MAX_WIDTH of %d pixels\n",
+				MAX_WIDTH);
+			exit(1);
+		}
+		pix16[npix++] = hexdecode(cp);
+		cp += 4;
+	}
+	xi = convert_function(pix16, npix);
+	XPutImage(mydisplay, mainwindow, mainwingc, xi, 0, 0, blitcol, blitrow,
+		  npix, 1);
+	XDestroyImage(xi);
+}
+
+input_on_stdin(inbuf, incount)
+	char *inbuf;
+{
+	char *input_end = inbuf + incount;
+	static char linebuf[1024];
+	static int linesz;
+	char *cp;
+
+	for (cp = inbuf; cp < input_end; cp++) {
+		if (*cp == '\n') {
+			linebuf[linesz] = '\0';
+			process_input_line(linebuf);
+			linesz = 0;
+			continue;
+		}
+		if (linesz < sizeof(linebuf) - 1)
+			linebuf[linesz++] = *cp;
+	}
+}