00001 *************************
00002 *
00003 * CKPGNV.ASM
00004 * (+n -- +n flag)
00005 * MDJ 01-23-91
00006 *
00007 * CHECKS IF PAGE NUMBER
00008 * +n ON THE TOP OF THE 
00009 * U-STACK IS A VALID PAGE
00010 * NUMBER FOR THE 
00011 * DOCUMENT BEING READ
00012 *
00013 * flag IS TRUE (#$FFFF)
00014 * IFF PAGE NUMBER IS
00015 * VALID
00016 *
00017 *************************
00018 *
00019 MAXPP   EQU     $3104
00020         ORG     $5899
00021 CKPGNV  PSHS    X
00022         PULU    X       GET PAGE NUMBER
00023         PSHU    X       RE-PUSH IT
00024         CMPX    #1      BELOW MINIMUM PAGE NUMBER?
00025         BLO     CKV1    GO IF YES
00026         CMPX    MAXPP   ABOVE MAXIMUM PAGE NUMBER?
00027         BHI     CKV1    GO IF YES
00028         LDX     #$FFFF  TRUE FLAG
00029         BRA     CKV2
00030 CKV1    LDX     #0      FALSE FLAG
00031 CKV2    PSHU    X
00032         PULS    X
00033 ZEND    RTS
00034         END
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
