T A B L E o f H I G H M E M O R Y A R E A
S E G M E N T : O F F S E T
P A I R S
Due to the fact that the Segment:Offset Addressing Scheme allows for only
65,536 segments (from 0000 to FFFFh), each byte in memory above the 1 MB
boundary will have one less Segment:Offset combination that can be used
to refer to its location as we move into each 16 byte paragraph above the
boundary. When we reach the last paragraph of the HMA (High Memory Area),
there's only one Segment:Offset pair that can be used to point to each of
those 16 bytes.
Memory locations ABOVE 1 Megabyte -- Counting from the beginning of
================================= each 16-byte paragraph...
ABSOLUTE RELATIVE ADDRESSING
DECIMAL HEX USING THE SEGMENT:OFFSET SCHEME
--------- --------- ---------------------------------------------
1,048,576 = 10 0000 h = F001:FFF0 = F002:FFE0 = F003:FFD0 = F004:FFC0 etc.
(thru FFFF:0010 for a total of 4,095 combinations.)
1,048,592 = 10 0010 h = F002:FFF0 = F003:FFE0 = F004:FFD0 = F005:FFC0 etc.
(thru FFFF:0020 for a total of 4,094 combinations.)
1,048,608 = 10 0020 h = F003:FFF0 = F004:FFE0 = F005:FFD0 = F006:FFC0 etc.
(thru FFFF:0030 for a total of 4,093 combinations.)
1,048,624 = 10 0030 h = F004:FFF0 = F005:FFE0 = F006:FFD0 = F007:FFC0 etc.
(thru FFFF:0040 for a total of 4,092 combinations.)
1,048,640 = 10 0040 h = F005:FFF0 = F006:FFE0 = F007:FFD0 = F008:FFC0 etc.
(thru FFFF:0050 for a total of 4,091 combinations.)
1,048,656 = 10 0050 h = F006:FFF0 = F007:FFE0 = F008:FFD0 = F009:FFC0 etc.
(thru FFFF:0060 for a total of 4,090 combinations.)
1,048,672 = 10 0060 h = F007:FFF0 = F008:FFE0 = F009:FFD0 = F00A:FFC0 etc.
(thru FFFF:0070 for a total of 4,089 combinations.)
1,048,688 = 10 0070 h = F008:FFF0 = F009:FFE0 = F00A:FFD0 = F00B:FFC0 etc.
(thru FFFF:0080 for a total of 4,088 combinations.)
e t c .
1,048,880 = 10 0130 h = F014:FFF0 = F015:FFE0 = F016:FFD0 = F017:FFC0 etc.
thru FFFF:0140 for a total of 4,075 combinations.
e t c . e t c . e t c .
1,052,992 = 10 1140 h = F115:FFF0 = F116:FFE0 = F117:FFD0 = F118:FFC0 etc.
thru FFFF:1150 for a total of 3,819 combinations.
e t c . e t c . e t c .
1,069,376 = 10 5140 h = F515:FFF0 = F516:FFE0 = F517:FFD0 = F518:FFC0 etc.
thru FFFF:5150 for a total of 2,795 references.
e t c . e t c . e t c .
1,085,760 = 10 9140 h = F915:FFF0 = F916:FFE0 = F917:FFD0 = F919:FFC0 etc.
thru FFFF:9150 for a total of 1,771 combinations.
e t c . e t c . e t c .
1,102,144 = 10 D140 h = FD15:FFF0 = FD16:FFE0 = FD17:FFD0 = FD19:FFC0 etc.
thru FFFF:D150 for a total of 747 combinations.
e t c . e t c . e t c .
1,110,336 = 10 F140 h = FF15:FFF0 = FF16:FFE0 = FF17:FFD0 = FF19:FFC0 etc.
thru FFFF:F150 for a total of 235 combinations.
e t c . e t c . e t c .
1,113,840 = 10 FEF0 h = FFF0:FFF0 = FFF1:FFE0 = FFF2:FFD0 = FFF3:FFC0 etc.
thru FFFF:FF00 for a total of 16 combinations.
e t c .
1,113,968 = 10 FF70 h = FFF8:FFF0 = FFF9:FFE0 = FFFA:FFD0 = FFFB:FFC0
= FFFC:FFB0 = FFFD:FFA0 = FFFE:FF90 = FFFF:FF80. (8)
1,113,984 = 10 FF80 h = FFF9:FFF0 = FFFA:FFE0 = FFFB:FFD0 = FFFC:FFC0
= FFFD:FFB0 = FFFE:FFA0 = FFFF:FF90. (7)
1,114,000 = 10 FF90 h = FFFA:FFF0 = FFFB:FFE0 = FFFC:FFD0 = FFFD:FFC0
= FFFE:FFB0 = FFFF:FFA0. (6)
1,114,016 = 10 FFA0 h = FFFB:FFF0 = FFFC:FFE0 = FFFD:FFD0 = FFFE:FFC0
= FFFF:FFB0. (5)
1,114,032 = 10 FFB0 h = FFFC:FFF0 = FFFD:FFE0 = FFFE:FFD0 = FFFF:FFC0. (4)
1,114,048 = 10 FFC0 h = FFFD:FFF0 = FFFE:FFE0 = FFFF:FFD0. (3)
1,114,064 = 10 FFD0 h = FFFE:FFF0 = FFFF:FFE0. (2)
1,114,080 = 10 FFE0 h = FFFF:FFF0. (1)
----------------------------------
1,114,095 = 10 FFEF h = FFFF:FFFF <--- The last byte accessible using the
Segment:Offset scheme; for a total
of 1,114,096 bytes of memory.
EOF. The Starman. 10 August 2001.