Works, but is a bit slower than expected (Linux bug?).

slowcat/.vimrc

@@ -0,0 +1,36 @@
+version 5.0
+set nocompatible
+let cpo_save=&cpo
+set cpo=B
+map! <xHome> <Home>
+map! <xEnd> <End>
+map! <S-xF4> <S-F4>
+map! <S-xF3> <S-F3>
+map! <S-xF2> <S-F2>
+map! <S-xF1> <S-F1>
+map! <xF4> <F4>
+map! <xF3> <F3>
+map! <xF2> <F2>
+map! <xF1> <F1>
+map <F8> :cn
+map <xHome> <Home>
+map <xEnd> <End>
+map <S-xF4> <S-F4>
+map <S-xF3> <S-F3>
+map <S-xF2> <S-F2>
+map <S-xF1> <S-F1>
+map <xF4> <F4>
+map <xF3> <F3>
+map <xF2> <F2>
+map <xF1> <F1>
+map!  }I\begin{yyplcwendO
+map!  >I<yypa/O
+let &cpo=cpo_save
+unlet cpo_save
+set autoindent
+set exrc
+set number
+set ruler
+set shiftwidth=4
+set showmatch
+set textwidth=72

slowcat/GNUmakefile

@@ -0,0 +1,13 @@
+include GNUmakevars
+include GNUmakerules
+
+all: slowcat
+install: $(BINDIR)/slowcat
+
+clean:
+	rm -f *.bak *.o core slowcat
+
+distclean: clean
+	rm -f *.d
+
+-include *.d

slowcat/slowcat.c

@@ -0,0 +1,70 @@
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+char *cmnd; 
+
+static void usage(void) {
+    fprintf(stderr, "Usage: %s [-d delay] file ...\n", cmnd);
+    exit(1);
+}
+
+
+static void do_cat(FILE *fp, double delay) {
+    int c;
+
+    while ((c = getc(fp)) != EOF) {
+	putchar(c);
+	usleep(delay * 1E6);
+    }
+}
+
+
+int main(int argc, char **argv) {
+    int rc = 0;
+    int c;
+    double delay = 0.5;
+
+    cmnd = argv[0];
+
+    while ((c = getopt(argc, argv, "d:")) != EOF) {
+        char *p;
+	switch (c) {
+	    case 'd':
+		p = NULL;
+		delay = strtod(optarg, &p);
+		if (!p || *p) usage();
+		if (delay < 0 || delay > ULONG_MAX / 1E6) usage();
+		break;
+	    case '?':
+		usage();
+	    default:
+		assert(0);
+	}
+    }
+
+    setvbuf(stdout, NULL, _IONBF, 0);
+
+    if (optind == argc) {
+	do_cat(stdin, delay);
+    } else {
+	int i;
+
+	for (i = optind; i < argc; i++) {
+	    FILE *fp = fopen(argv[i], "r");
+	    if (fp) {
+		do_cat(fp, delay);
+		fclose(fp);
+	    } else {
+		fprintf(stderr, "%s: cannot open %s for reading: %s\n",
+			argv[0], argv[i], strerror(errno));
+		rc++;
+	    }
+	}
+    }
+    return rc;
+}