Commodore PET User Manual page 347

Table 6-2. PET Memory Map (Rev 3 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
Evaluation of Variables and
Terminal 1/0 Maintenance
3 0003
0 00
Search character
4 0004
0 00
Delimiter flag for quote mode scan
5 0005
255 FF
Input buller pointer. general
counter
6
0006
0 00
Flag for dimensioned variables
7 0007
0 00
Flag for variable type:
OO~numeric
FF~string
8 0008
0 00
Flag for numerlc variable type:
OO~floating point
80~lnteger
9 0009
0 00
Flag for DATA scan; LIST quote; memory
10 OOOA
0 00
Flag to allow subscrlpted variable; FNx flag
11 OOOB
0
00
Flag for Input type
O~INPUT
64~GET
152~READ
12
OOOC 0
00
Flag for ATN slgn; comparison evaluation
13 0000
0 00
Flag to suppress output
+
normal
.- suppressed
14
OOOE
0 00
Current 1/0 device for prompt-suppress
15 OOOF
40 28
Terminai width (unusedl
16 0010
30 1E
lImit for scannlng source columns lunusedl
17-18
0011-0012
828 033C
BasIc integer address (for SYS. GOTO. etc)
19
0013
22
16
Index to next available descriptor
20-21 0014-0015
19 13
Pointer to last string temporary
22-29 0016-0010
2
0002
Table of double-byte descriptions that point
to variables 18 bytes)
30-31 001 E-001 F
16451 4043
Indirect index *1
32-33 0020-0021
26119 6607
Indirect index *2
34 0022
1 01
Pseudo-register for function
operands (6 bytes)
35 0023 140
8C
36 0024
0 00
37 0025
0 00
38 0026
0 00
39 0027
0 00
334