Table 6-2.
PET
Memory Map
(Rev.
3 ROMs) (Continued)
Memory Address
Sample Value
Decimal
40-41
42-43
44-45
46-47
48-49
50-51
52-53
54-55
56-57
58-59
60-61
62-63
64-65
66-67
68-69
70-71
72-73
74
75-76
77-78
79
80
81
82-83
84-89
90-91
92-93
94-99
100
101
102-107
108
109
110-111
Hexadecimal
0028-0029
002A-0028
002C-0020
002E-002F
0030-0031
0032-0033
0034-0035
0036-0037
0038-0039
003A-0038
003C-0030
003E-003F
0040-0041
0042-0043
0044-0045
0046-0047
0048-0049
004A
0048-004C
0040-004E
004F
0050
0051
0052-0053
0054-0059
005A-0058
005C-0050
005E-0063
0064
0065
0066-006B
006C
0060
006E-006F
Decimal
1025
1920
2032
2191
8192
8191
8192
2000
110
lB97
200
1855
514
B9
2006
2006
1279
o
62268
26531
243
3
76
o
211
o
o
o
o
o
o
o
o
o
o
o
o
o
25B
Hexadecimal
0401
0780
07FO
088F
2000
1
FFF
2000
0700
006E
0769
00C8
073F
0202
0059
0706
0706
04FF
00
F33C
67A3
F3
03
4C
00
03
0000
0000
00
00
00
00
00
00
00
00
00
00
00
0102
Description
Data Storage Maintenance
POinter ta start of BASIC
text
POinter ta start of variables
POinter ta end of
variables
Pal
nter ta end of arrays
POinter ta start of strings Imovlng
downl
POinter
ta
end of strings Itop of avadable
RAMI
POinter ta
Ilmlt
of BASIC
memory
Current Ilne number. Loc
55~2
If no
program
yet executed
Prevlous line
number
POinter ta next line ta
be
executed (for
CONTI
Llne
number
of current OATA line
POinter
ta
current OATA Item
Expression Evaluation
1NPUT vector
Current variable
name
Pointer to current variable
POinter
ta
current
FOR
NEXT variable
POinter ta
current
operator ln ROM table
Mask for
current
logical operator
POinter ta user
functlon
FN
deflnitlon
Pointer to a string description
Length of string
Constant used by garbage
collection
routine
Constant 6502 JMP
instruction
Jump
vector for functions
Floatlng
point
accumulator
*3
16
bytesl
Black transfer
pOinter * 1
Black transfer pOinter
*2
Floatlng pOint
accumulator
(FACI
* 1
16
bytesl
94 005E Exponent
+128
95 005F Fraction MSB
Floatlng POint
96
0060
Fraction
97 0061 Fraction MSB Integer
98 0062 Fraction
LSB
99 0063 Sign
of
fraction
10
If zero or
positive.
1 If neyativel
Copy of
FAC
* 1 slgn of fraction
Counter for
number
of
bits
ta
shlft
ta nor-
mal,ze
FAC
*1
Floating pOint
accumulator
*2
(6
bytesl
Overflow
byte
for
floatlng
argument
Copy of FAC
*2
sign of fraction
Conversion pointer
335
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