[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Cycle by Cycle Emulator



....I have succeeded by writing 6502 emulator that it contains 2,048
functions.  Yes, it is very huge to be exact 2,048 functions, but some
of them are unused or reserved because of unused instructions.  It is
designed to emulate at cycle by cycle unlike instruction by
instruction that most emulators have instruction by instruction.
....It is very accurate because it looks like simulator or real 6502
timing.  Some programmers claim that cycle by cycle emulator can be
very slow on previous microprocessor such as 486 and original Pentium.
 I always disagree with them if they claim to be slow on Pentium II
and Pentium III.
....Apple II Plus is the first cycle by cycle emulator under my
project that it runs at 1MHz on Pentium III 550MHz and Xeon Pentium
550MHz.  It can also run at 2MHz to 8MHz.  It is very hopeful that it
will run at 30MHz to 100MHz on Pentium 4 5GHz or higher.
....Some people claim that decimal mode using ADC and SBC instruction
are not real 6502 timing when they can cause many problems on emulator
project.  My cycle by cycle emulator is able to emulate decimal mode
into real 6502 timing and it is identical to real 6502's bug because I
am able to reproduce 6502 bugs on cycle by cycle emulator, but it is
not emulator bug.
....I predict that cycle by cycle emulator is always 100% perfect
according to my desire, but I will see what happen.
....I need your comments why you agree or disagree by writing
instruction by instruction emulator and cycle by cycle emulator.  I
want to hear your opinion.  It is my first project that it is never
announced.

Bryan Parkoff