diff --git a/26_day/bootpack.c b/26_day/bootpack.c
index 3ec1287..8d16a9e 100644
--- a/26_day/bootpack.c
+++ b/26_day/bootpack.c
@@ -8,6 +8,8 @@
 void keywin_off(struct SHEET *key_win);
 void keywin_on(struct SHEET *key_win);
 struct SHEET *open_console(struct SHTCTL *shtctl, unsigned int memtotal);
+void close_console(struct SHEET *sht);
+void close_constask(struct TASK *task);
 
 void HariMain(void)
 {
@@ -51,6 +53,7 @@ void HariMain(void)
 	init_pic();
 	io_sti(); /* IDT/PIC的初始化已经完成，于是开放CPU的中断 */
 	fifo32_init(&fifo, 128, fifobuf, 0);
+	*((int *) 0x0fec) = (int) &fifo;
 	init_pit();
 	init_keyboard(&fifo, 256);
 	enable_mouse(&fifo, 512, &mdec);
@@ -123,9 +126,13 @@ void HariMain(void)
 		} else {
 			i = fifo32_get(&fifo);
 			io_sti();
-			if (key_win->flags == 0) { /*输入窗口被关闭*/
-				key_win = shtctl->sheets[shtctl->top - 1];
-				keywin_on(key_win);
+			if (key_win != 0 && key_win->flags == 0) { /*窗口被关闭*/
+				if (shtctl->top == 1) { /*当画面上只剩鼠标和背景时*/
+					key_win = 0;
+				} else {
+					key_win = shtctl->sheets[shtctl->top - 1];
+					keywin_on(key_win);
+				}
 			}
 			if (256 <= i && i <= 511) { /* 键盘数据*/
 				if (i < 0x80 + 256) { /*将按键编码转换为字符编码*/
@@ -143,10 +150,10 @@ void HariMain(void)
 						s[0] += 0x20; /*将大写字母转换为小写字母*/
 					}
 				}
-				if (s[0] != 0) { /*一般字符、退格键、回车键*/
+				if (s[0] != 0 && key_win != 0) { /*一般字符、退格键、回车键*/
 					fifo32_put(&key_win->task->fifo, s[0] + 256);
 				}
-				if (i == 256 + 0x0f) {	/* Tab键 */
+				if (i == 256 + 0x0f && key_win != 0) {	/* Tab键 */
 					keywin_off(key_win);
 					j = key_win->height - 1;
 					if (j == 0) {
@@ -182,7 +189,7 @@ void HariMain(void)
 					fifo32_put(&keycmd, KEYCMD_LED);
 					fifo32_put(&keycmd, key_leds);
 				}
-				if (i == 256 + 0x3b && key_shift != 0) {
+				if (i == 256 + 0x3b && key_shift != 0 && key_win != 0) {
 					task = key_win->task;
 					if (task != 0 && task->tss.ss0 != 0) {	/* Shift+F1 */
 						cons_putstr0(task->cons, "\nBreak(key) :\n");
@@ -192,8 +199,10 @@ void HariMain(void)
 						io_sti();
 					}
 				}
-				if (i == 256 + 0x3c && key_shift != 0 ) { /* Shift+F2 */
-					keywin_off(key_win);
+				if (i == 256 + 0x3c && key_shift != 0) { /* Shift+F2 */
+					if (key_win != 0) {
+						keywin_off(key_win);
+					}
 					key_win = open_console(shtctl, memtotal);
 					sheet_slide(key_win, 32, 4);
 					sheet_updown(key_win, shtctl->top);
@@ -282,6 +291,8 @@ void HariMain(void)
 						} 
 					}
 				}
+			} else if (768 <= i && i <= 1023) { /*命令行窗口关闭处理*/
+				close_console(shtctl->sheets0 + (i - 768));
 			}
 		}
 	}
@@ -311,6 +322,8 @@ struct SHEET *open_console(struct SHTCTL *shtctl, unsigned int memtotal)
 	struct SHEET *sht = sheet_alloc(shtctl);
 	unsigned char *buf = (unsigned char *) memman_alloc_4k(memman, 256 * 165);
 	struct TASK *task = task_alloc();
+	task->cons_stack = memman_alloc_4k(memman, 64 * 1024);
+	task->tss.esp = task->cons_stack + 64 * 1024 - 12;
 	int *cons_fifo = (int *) memman_alloc_4k(memman, 128 * 4);
 	sheet_setbuf(sht, buf, 256, 165, -1); /*无透明色*/
 	make_window8(buf, 256, 165, "console", 0);
@@ -331,3 +344,23 @@ struct SHEET *open_console(struct SHTCTL *shtctl, unsigned int memtotal)
 	fifo32_init(&task->fifo, 128, cons_fifo, task);
 	return sht;
 }
+
+void close_constask(struct TASK *task)
+{
+	struct MEMMAN *memman = (struct MEMMAN *) MEMMAN_ADDR;
+	task_sleep(task);
+	memman_free_4k(memman, task->cons_stack, 64 * 1024);
+	memman_free_4k(memman, (int) task->fifo.buf, 128 * 4);
+	task->flags = 0; /*用来替代task_free(task); */
+	return;
+}
+
+void close_console(struct SHEET *sht)
+{
+	struct MEMMAN *memman = (struct MEMMAN *) MEMMAN_ADDR;
+	struct TASK *task = sht->task;
+	memman_free_4k(memman, (int) sht->buf, 256 * 165);
+	sheet_free(sht);
+	close_constask(task);
+	return;
+}
diff --git a/26_day/bootpack.h b/26_day/bootpack.h
index 9975f09..31a6385 100644
--- a/26_day/bootpack.h
+++ b/26_day/bootpack.h
@@ -211,7 +211,7 @@ struct TASK {
 	struct FIFO32 fifo;
 	struct TSS32 tss;
 	struct CONSOLE *cons;
-	int ds_base;
+	int ds_base, cons_stack;
 };
 struct TASKLEVEL {
 	int running; /*正在运行的任务数量*/
@@ -255,6 +255,7 @@ void cmd_mem(struct CONSOLE *cons, int memtotal);
 void cmd_cls(struct CONSOLE *cons);
 void cmd_dir(struct CONSOLE *cons);
 void cmd_type(struct CONSOLE *cons, int *fat, char *cmdline);
+void cmd_exit(struct CONSOLE *cons, int *fat);
 int cmd_app(struct CONSOLE *cons, int *fat, char *cmdline);
 int *hrb_api(int edi, int esi, int ebp, int esp, int ebx, int edx, int ecx, int eax);
 int *inthandler0d(int *esp);
diff --git a/26_day/console.c b/26_day/console.c
index 1b39bc1..d219b85 100644
--- a/26_day/console.c
+++ b/26_day/console.c
@@ -173,6 +173,8 @@ void cons_runcmd(char *cmdline, struct CONSOLE *cons, int *fat, int memtotal)
 		cmd_dir(cons);
 	} else if (strncmp(cmdline, "type ", 5) == 0) {
 		cmd_type(cons, fat, cmdline);
+	} else if (strcmp(cmdline, "exit") == 0) {
+		cmd_exit(cons, fat);
 	} else if (cmdline[0] != 0) {
 		if (cmd_app(cons, fat, cmdline) == 0) {
 			/*不是命令，不是应用程序，也不是空行*/
@@ -250,6 +252,22 @@ void cmd_type(struct CONSOLE *cons, int *fat, char *cmdline)
 	return;
 }
 
+void cmd_exit(struct CONSOLE *cons, int *fat)
+{
+	struct MEMMAN *memman = (struct MEMMAN *) MEMMAN_ADDR;
+	struct TASK *task = task_now();
+	struct SHTCTL *shtctl = (struct SHTCTL *) *((int *) 0x0fe4);
+	struct FIFO32 *fifo = (struct FIFO32 *) *((int *) 0x0fec);
+	timer_cancel(cons->timer);
+	memman_free_4k(memman, (int) fat, 4 * 2880);
+	io_cli();
+	fifo32_put(fifo, cons->sht - shtctl->sheets0 + 768); /* 768〜1023 */
+	io_sti();
+	for (;;) {
+		task_sleep(task);
+	}
+}
+
 int cmd_app(struct CONSOLE *cons, int *fat, char *cmdline)
 {
 	struct MEMMAN *memman = (struct MEMMAN *) MEMMAN_ADDR;