Commodore 2001-8 User Manual page 121

PAGE
o
1
2
TYPE
PIA
PIA
VIA
START
ADDRESS
$E810
$E820
$E840
I/O Device Base Addresses
FUNCTION
Keyboard
IEEE-488
USA PORT
cassette
Location not specified are used but have no clear one function definition.
PET PAGE ZERO MEMORY MAP
000
001 002
Terminal
1/0
maintenance
003
004
005
006
007
008
009
010 089 .
090
091
092
Evaluation of variables
093
094
095
096
097
098
099
100
101
102 103
104 111
112 113
114 115
116 121
Data storage maintenance
122 123
124 125
126 127
128 129
130 131
132 133
i
jl
134 135
136 137
FROM
138
140
142
144
TO
139
141
143
145
DESCRIPTION
$4C constant (6502 JMP instruction).
USR function address 10, hi.
Active
1/0
channel
#.
Nulls to print for CRLF (unused).
Column BASIC is printing next.
Terminal width (unused).
Limit for scanning source columns (unused).
Line number storage before buffer.
$2C constant (special comma for INPUT process).
BASIC INPUT buffer (80 bytes).
General counter for BASIC.
$00 used as delimater.
General counter for BASIC.
Flag to remember dimensioned variables.
Flag for variable type; O#numeric; 1 -:-string.
Flag for integer tape.
Flag to crunch reserved words (protects '& remark).
Flag which allows subscripts in syntax.
Flags INPUT or READ.
Flag sign of TAN.
Flag to suppress OUTPUT (+ normal; - suppressed).
Index to next available descriptor.
Pointer to last string temporary 10; hi.
Table of double byte descriptors which point to vaiables.
Indirect index #1 10; hi.
Indirect index #210; hi.
Pseudo register for function operands.
Pointer to start of BASIC text area 10; hi byte.
Pointer to start of variables 10; hi byte.
Pointer to array table 10; hi byte.
Pointer to end of variables 10; hi byte.
Pointer to start of strings 10; hi byte.
Pointer to top string space 10; hi byte.
Highest RAM adr 10; hi byte.
Current line being executed. A zero in 136 means statement
executed in a direct command.
Line # for continue command 10; hi.
Pointer to next STMNT to execute 10; hi.
Data tine # for errors 10; hi.
Data statement pointer 10; hi.
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