Table
G-l.
PET
Memory Map
(Rev
2
ROMs)
Memory Address Sample Value
Description
Decimal
Hexadecimal Decimal
Hexadecimal
Page
0 (0-255)·
USR Function Locations
0 0000 76
4C
Constant 6502 JMP instruction
1-2
0001-0002 826 033A
User address jump vector
Terminal
1/0
Maintenance
3
0003
0 00
Active input device number
(O=keyboard)
4 0004
0 00
No.
of nulls
to
print alter CR/LF
(O=normall
5
0005
0
00
Cursor position for
pas
function (0-255)
6 0006
127
7F
Terminal
width
(unusedl
7 0007 127
7F
Limit for scanning source columns
(unused)
8 0008 60
3C
Line number storage preceding buller
9 0009 3
03
Constant
10-89 000A-0059
48
30
BASIC input line buller (80 bytes)
90 005A 0
00
General counter for
BASIC
91
005B
0
00
Delimiter flag for quote mode scan
92
005C
255
FF
Input buller pointer. general counter
Evaluation of Variables
93
0050
0
00
Flag for dimensioned variables
94
005E a
00
Flag for variable type:
OO~numeric
FF=string
95 005F
0
00
Flag for numeric variable type:
OO=floating point
80=integer
96 0060 0
00
Flag to allow reserved words
in
strings
and remarks
97
0061
0 00
Flag to allow subscripted variable
98 0062 0
00
Flag for input type:
O~INPUT
64=GET
152=READ
99 0063
0
00
Flag sign of TAN function
100 0064
0
00
Flag
to suppress output:
+ normal
--
suppressed
101
0065 104
68
Index to next available descriptor
102-103 0066-0067
101
0065
Pointer
ta
last string temporary
104-111 0068-006F
2 0002
Table of double-byte descriptors that
point to variables
(8
bytes)
112-113 0070-0071 14525
3880
Indirect index * 1
114-115
0072-0073
62983 F607
Indirect index
*2
116 0074
1
01
Pseudo-register for function operands
(6
bytes)
117 0075 234
EA
118
0076
0 00
119
0077 0
00
120
0078
a
00
121
0079
0
00
414
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