AND.L 中使用的掩码（“防止 divu 溢出”）仅适用于除以 100 - 您需要使用0x7FFFF 进行掩码才能除以 10。
为什么：
0xFFFFFFFF / #100 = 0x28f5c28 - too big for a single word!
0x5FFFFF / #100 = 0xF5C2 - that fits
0x5FFFFF / #10 = 0x99999 - too big for a single word!
0x7FFFF / #10 = 0xCCCC - that fits
此外，您拥有的代码将为您提供一个从 1 到 10 (0-9 + 1) 的数字。如果要 2 到 11，则必须加 2，而不是 1。
这是一个更高级的随机数生成器，它是从 Mac OS QuickDraw 源代码中借用的。请注意，您可能需要对语法进行一些翻译（它是在 25 年前编写的！）和/或修改它加载和存储种子的方式。
;--------------------------------------------------------------
;
; FUNCTION Random: INTEGER;
;
; returns a signed 16 bit number, and updates unsigned 32 bit randSeed.
;
; recursion is randSeed := (randSeed * 16807) MOD 2147483647.
;
; See paper by Linus Schrage, A More Portable Fortran Random Number Generator
; ACM Trans Math Software Vol 5, No. 2, June 1979, Pages 132-138.
;
; Clobbers D0-D2, A0
;
;
; GET LO 16 BITS OF SEED AND FORM LO PRODUCT
; xalo := A * LoWord(seed)
;
MOVE.L GRAFGLOBALS(A5),A0 ;POINT TO QuickDraw GLOBALS
MOVE #16807,D0 ;GET A = 7^5
MOVE D0,D2 ;GET A = 7^5
MULU RANDSEED+2(A0),D0 ;CALC LO PRODUCT = XALO
;
; FORM 31 HIGHEST BITS OF LO PRODUCT
; fhi:=HiWord(seed) * ORD4(a) + HiWord(xalo);
;
MOVE.L D0,D1 ;COPY xalo
CLR.W D1
SWAP D1 ;GET HiWord(xalo) as a long
MULU RANDSEED(A0),D2 ;MULT BY HiWord(seed)
ADD.L D1,D2 ;ADD LEFTLO = FHI
;
; GET OVERFLOW PAST 31ST BIT OF FULL PRODUCT
; k:=fhi DIV 32768;
;
MOVE.L D2,D1 ;COPY FHI
ADD.L D1,D1 ;CALC 2 TIMES FHI
CLR.W D1
SWAP D1 ;CALC FHI SHIFTED RIGHT 15 FOR K
;
; ASSEMBLE ALL THE PARTS AND PRE-SUBTRACT P
; seed:=((BitAnd(XALO,$0000FFFF) - P) + BitAnd(fhi,$00007FFF) * b16) + K;
;
AND.L #$0000FFFF,D0 ;GET LO WORD XALO
SUB.L #$7FFFFFFF,D0 ;SUBTRACT P = 2^31-1
AND.L #$00007FFF,D2 ;BitAnd(fhi,$00007FFF)
SWAP D2 ;TIMES 64K
ADD.L D1,D2 ;PLUS K
ADD.L D2,D0 ;CALC TOTAL
;
; IF seed < 0 THEN seed:=seed+p;
;
BPL.S UPDATE
ADD.L #$7FFFFFFF,D0
UPDATE MOVE.L D0,RANDSEED(A0) ;UPDATE SEED
CMP.W #$8000,D0 ;IS NUMBER -32768 ?
BNE.S NUMOK ;NO, CONTINUE
CLR D0 ;YES, RETURN ZERO INSTEAD
NUMOK MOVE.W D0,4(SP) ;RETURN LO WORD AS RESULT
RTS