Computing (FOLDOC) dictionary
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Unlike the
Intel 8080 and its kind, the 6502 had very few
was preset from address 256 to 511). It used these index and
including a fast zero-page mode that accessed memory locations
from address 0 to 255 with an 8-bit address (it didn't have to
fetch a second byte for the address).
Back when the 6502 was introduced,
RAM was actually faster
than
CPUs, so it made sense to optimize for RAM access
rather than increase the number of registers on a chip.
you could get for less than a hundred dollars (actually a
quarter of the
6800 price).
broken. If the address was hexadecimal xxFF, the processor
would not access the address stored in xxFF and xxFF + 1, but
rather xxFF and xx00. The
6510 did not fix this bug, nor
was it fixed in any of the other
NMOS versions of the 6502
was probably the first to fix it, in the
65C02.
The 6502 also had undocumented instructions.
The
65816 is an expanded version of the 6502.
which supports
macros and conditional features and can be
used for linkage editing of object files. It requires
(2001-01-02)