00001 *************************
00002 *
00003 * CKPGN.ASM
00004 * (+n -- +n flag)
00005 * MDJ 01-23-91
00006 *
00007 * CHECKS IF PAGE NUMBER
00008 * +n ON TOP OF THE
00009 * U-STACK IS WITHIN THE
00010 * PAGE NUMBER RANGE FOR
00011 * THE DISK BEING READ
00012 *
00013 * flag IS TRUE (#$FFFF)
00014 * IFF PAGE NUMBER IS IN
00015 * RANGE
00016 *
00017 *************************
00018 *
00019 MINP    EQU     $3100
00020 MAXP    EQU     $3102
00021         ORG     $58B6
00022 CKPGN   PSHS    X
00023         PULU    X       GET PAGE NUMBER
00024         PSHU    X       RE-PUSH IT
00025         CMPX    MINP    BELOW DISK MIN. PAGE NUMBER?
00026         BLO     CK1     GO IF YES
00027         CMPX    MAXP    ABOVE DISK MAX. PAGE NUMBER
00028         BHI     CK1     GO IF YES
00029         LDX     #$FFFF  TRUE FLAG
00030         BRA     CK2
00031 CK1     LDX     #0      FALSE FLAG
00032 CK2     PSHU    X
00033         PULS    X
00034 ZEND    RTS
00035         END
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
