Table 6-2.
PET
Memory
Map
(Rev.
3 ROMs) (Continuedl
Memory Address
Sample Value
Description
Decimal
Hexadecimal Decimal Hexadecimal
OS
Page Zero Storage IContinuedl
173
OOAO
0
00
1/0 utdlty: X save flag
174
OOAE
1
01
Number of open files lindex Into tablesl
175
OOAF
0
00
Oefault Input devlce number
10~keyboardl
176
OOBO
3
03
Oefault
output
devlce number
13~screenl
177
OOBl
0
00
Tape
pallty
byte
17B
00B2
0
00
Flag for byte recelved
179 00B3
0
00
1/0
utlilty
180 00B4 0
00
Tape buffer character
181
00B5
0
00
Byte pOinter ln fdename transfer
182
00B6
0
00
1/0
utdlty
183 00B7 0
00
Sellai bit count
184 00B8 0
00
Tape
utlilty
185
00B9
0
00
Cycle counter -
flip
for each
bit
read from
tape
186
OOBA
0
00
Countdown synchronlzatlon on tape
write
187
OOBB
0
00
Tape buffer 1
rndex
ta
next character
188
OOBC
0
00
Tape buffer 2 rndex
ta
next character
189
OOBO
0
00
Countdown synchronizatlon on tape read
190
OOBE
0
00
Flag
ta
rndicate
bit/byte
tape error
191
OOBF
0
00
Flag
ta
rndlcate tape error
O~f"st
half-byte marker not
wlltten
192
OOCO
0
00
Flag
ta
rndicate tape error
0~2nd
half-byte marker not
wlltten
193
OOCl
0
00
Tape dropout counter
194
00C2 0
00
Flag
for cassette read current
functlon
O~scan.
1-
15~count.
4016~load.
8016~end
195 00C3 0
00
Checksum
utility
196-197
00C4-00C5 33728
83CD
Pointer ta start of line where cursor
IS
flash-
Ing
198
00C6 0
00
Column position where cursor
is
flashing
10-
791
199-200
00C7-00C8 33792
8400
Load start address:
utdlty
pornter
201-202
00C9-00CA 0
0000
Load end address
203-204
OOCB-OOCC
0
00
Tape
tlmrng constants
205
OOCD
0
00
Flag for quote mode
O~not
quote mode
206
OOCE
0
00
Flag for tape read
tlmer
enable
O~disabled
207
OOCF
0
00
Flag for
EOT
recelved from tape
208
0000
0
00
Read
character
error
209 0001 0
00
No.
of characters
in
current file name
210
0002
4
04
Current logical file number
211
0003
255
FF
Current secondary address
212
0004
4
04
Current device number
213
0005
39
27
Current screen
Irne
length
139.
791
214-215
0006-0007
0
0000
Pointer
ta
start of current tape buffer
1634
or
8261
337
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