300
The
VIC
20
User
Guide
TABLE
B-1:
Memory Map (continued)
Hex Decimal
Description
Address Address
0289
649
Maximum size
of
keyboard buffer
028A
650
Key repeat
(128
= repeat all keys)
028B
651
Repeat speed counter
028C
652
Repeat delay counter
028D
653
Keyboard Shift/ Control flag
028E
654
Last keyboard shift pattern
028F-0290
655-656
Pointer: Decode logic
0291
657
Shift mode switch
(0
= enabled,
128
= locked)
0292
658
Auto scroll down flag
(0
= on,
< > 0 = off)
0293
659
RS-232 control register
0294
660
RS-232 command register
0295-0296
661-662 Nonstandard (Bit time/2-100)
0297
663
RS-232 status register
0298
664
Number
of
bits
to
send
0299-029A
665-666 Baud rate (full) bit time
029B
667
RS-232 receive pointer
029C
668
RS-232 input pointer
029D
669
RS-232 transmit pointer
029E
670 RS-232 output pointer
029F-02AO
671-672 Holds
IRQ
during tape operations
02AI-02FF
673-767 Program indirects
0300-0301 768-769
Error message link
0302-0303 770-771
BASIC warm start link
0304-0305 772-773
Crunch BASIC tokens link
0306-0307
774-775
Print tokens link
0308-0309
776-777
Start new BASIC code link
030A-030B
778-779
Get arithmetic element link
030C
780
Storage for 6502 .A register
030D
781
Storage for 6502 .X register
030E
782
Storage for 6502
.Y
register
030F
783
Storage for 6502
.P
register
0314-0315 788-789
Hardware (IRQ) interrupt vector
(EABF)
0316-0317
790-791
Break interrupt vector
(FED2)
0318-0319
792-793
NMI
interrupt vector
(FEAD)
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