diff --git a/print16.asm b/print16.asm
index 5825978..86f421c 100644
--- a/print16.asm
+++ b/print16.asm
@@ -5,7 +5,7 @@
 print16:
 .scope
 .data zp
-.space _num 6
+.space _num 4
 .space _num_dec 6
 .text
 	pha
@@ -13,14 +13,13 @@ print16:
 	pha
 	
     lda #0
-    ldx #6
+    ldx #10
 *   dex
-    sta _num, x
-    sta _num_dec, x
+    sta _num - 1, x
     bne -
 
-	`splitbyte s, 4
-	`splitbyte s + 1, 2
+	`splitbyte s, 3
+	`splitbyte s + 1, 1
     `carry
 	`print _num_dec
 
@@ -29,43 +28,75 @@ print16:
 	pla
     rts
 
-_store:
-    adc _num_dec, y
-    sta _num_dec, y
-    ;jsr printbyte
-    rts
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; mod函数处理的数据为打印方便均使用大端序存储
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-_store2:
-    adc _num_dec, y
-    sta _num_dec, y
-    ;jsr printbyte
-    dey
+mod_4:      ; 高字节低4位若大于10，则向高位进1
+    lda _num + 3
+    cmp #10
+    bcc +
+    sbc #10             ; 此时c为1
+    tax
     lda #1
-    sta _num_dec, y
+    sta _num_dec + 3    ; 进位
+    txa
+*   sta _num_dec + 4
     rts
 
-mod_4: `mod10 4, $26
+mod_3:      ; 高字节高4位的值相当于个位加6，十位加1
+    ldx _num + 2
+    bne +   ; 如果为0直接返回
+    rts
+*   lda #6
+    `carry10 4
+    lda #1
+    `carry10 3
+    dex
+    bne -
+    rts
 
-mod_3: `mod10 3, $2c
+mod_2:      ; 低字节低4位的值相当于个位加6，十位加5，百位加2
+    ldx _num + 1
+    bne +   ; 如果为0直接返回
+    rts
+*   lda #6
+    `carry10 4
+    lda #5
+    `carry10 3
+    lda #2
+    `carry10 2
+    dex
+    bne -
+    rts
 
-mod_2: `mod10 2, $28
+mod_1:      ; 低字节低4位的值相当于个位加6，十位加9，百位加0，千位加4
+    ldx _num
+    bne +   ; 如果为0直接返回
+    rts
+*   lda #6
+    `carry10 4
+    lda #9
+    `carry10 3
+    lda #4
+    `carry10 1
+    dex
+    bne -
+    rts
 
-mod_1: `mod10 1, $2a
 .scend
 
-.macro mod10
-    ldy #_1
-    lda _num, y
-    ;jsr printbyte
-    cmp #10
+.macro carry10
     clc
-    bmi _s
-    adc #_2
-    jsr _store2
-    rts
-_s: adc #$30
-    jsr _store
-    rts
+    adc _num_dec + _1
+    bcc _skip
+    pha
+    adc _num_dec + _1 - 1
+    sta _num_dec + _1 - 1
+    pla
+_skip:
+    sta _num_dec + _1
+    ;jsr printbyte
 .macend
 
 .macro splitbyte
@@ -88,15 +119,45 @@ _s: adc #$30
     tya
     pha
 
+    sed         ; 设置为bcd加减法
     jsr mod_4
     jsr mod_3
     jsr mod_2
-    jsr mod_1
-    lda #$30
-    clc
-    adc _num_dec
-    sta _num_dec
-    
+    jsr mod_1   ; 此时结果中有些位可能大于10，需要进行进位处理
+    ldx #4
+_loop:
+    lda _num_dec, x
+    ldy #0      ; y记录进位数
+    cmp #10
+    bcc _skip   ; 小于10不进位
+    pha
+    ora #$f0
+    ror
+    ror
+    ror
+    ror
+    tay
+    pla
+    ora #$0f
+    sta _num_dec, x
+    tya
+    dex
+    adc _num_dec, x
+    sta _num_dec, x
+    inx
+_skip:
+    dex
+    bne _loop
+
+    cld         ; 退出bcd模式
+    lda #$30    ; 转化为可显示字符
+    ldx #5
+_up:
+    adc _num_dec - 1, x
+    sta _num_dec - 1, x
+    dex
+    bne _up
+
     pla
     tay
 .macend
diff --git a/printbyte.asm b/printbyte.asm
index b9a8c8c..7da63c8 100644
--- a/printbyte.asm
+++ b/printbyte.asm
@@ -2,6 +2,7 @@
 .space _na 1	; a的临时存放处
 .text
 printbyte:
+    php
     pha
     sta _na
     txa
@@ -18,4 +19,5 @@ printbyte:
     pla
     tax
     pla
+    plp
     rts
\ No newline at end of file
diff --git a/snake.prg b/snake.prg
index 8b44b5d..31e306d 100644
Binary files a/snake.prg and b/snake.prg differ