vic20: Increase framedrop during cassette access

src/arch/vic20/setup.c

···
 	sim->speed_auto = (aspeed != 0);
 	sim->speed_tape = 0;
 
+	sim->framedrop_base = 0;
+	sim->framedrop_tape = 0;
+
 	pce_log_tag (MSG_INF, "VIC20:",
 		"cpu=6502 clock=%lu speed=%u autospeed=%d pal=%d\n",
 		sim->clock, sim->speed, sim->speed_auto, sim->pal
···
 	if (snd != NULL) {
 		pce_log_tag (MSG_INF, "VIC:", "sound=%s\n", snd);
 	}
+
+	sim->framedrop_base = drop;
 
 	v20_video_init (&sim->video);
 

src/arch/vic20/vic20.c

···
 
 void v20_set_speed_tape (vic20_t *sim, unsigned char val)
 {
-	sim->speed_tape = (val != 0);
+	if (val) {
+		sim->speed_tape = 1;
+		sim->framedrop_tape = 4;
+	}
+	else {
+		sim->speed_tape = 0;
+		sim->framedrop_tape = 0;
+	}
 
 	v20_set_speed (sim, sim->speed_base);
 }
 
 void v20_set_speed (vic20_t *sim, unsigned speed)
 {
-	int report;
+	int      report;
+	unsigned drop;
 
 	report = (sim->speed_base != speed);
+
+	drop = sim->framedrop_base;
+
+	if (sim->framedrop_tape > drop) {
+		drop = sim->framedrop_tape;
+	}
+
+	v20_video_set_framedrop (&sim->video, drop);
 
 	sim->speed_base = speed;
 

src/arch/vic20/vic20.h

···
 	char          speed_auto;
 	char          speed_tape;
 
+	unsigned      framedrop_base;
+	unsigned      framedrop_tape;
+
 	unsigned long clock;
 	unsigned long sync_clk;
 	unsigned long sync_us;