6502 EMULATOR COMPUTERCRAFT FOR FREE
6502 EMULATOR COMPUTERCRAFT PC

6502 EMULATOR COMPUTERCRAFT FOR FREE

The information is provided for free and AS IS, therefore without any warranty without even the implied warranty of merchantability or fitness for a particular purpose. Load, store and transfer instructions as well as comparisons are typically found in the lower half of the table, while most of the arithmetical and logical operations as well as stack and jump instructions are found in the upper half.Р”Вisclaimer: Errors excepted. Address modes are either a property of b even columns or combinations of b and c odd columns with aspecific row-index modulus 3 i. Computercraft programsР”Р‡inally, a more complex view, the instruction set listed by rows as combinations of a and c, and b in columns. Mind that the two notations are interchangeable for any instructions involving the accumulator.Р”Р„ rotated view, rows as combinations of c and b, and columns as a. Generally, instructions of a kind are typically found in rows as a combination of a and cand address modes are in columns b.

The instruction table is laid out according to a pattern a-b-c, where a and b are an octal number each, followed by a group of two binary digits c, as in the bit-vector 'aaabbbcc'. These are recovered from the stack at the end of an interrupt routine by the RTI instruction.

6502 EMULATOR COMPUTERCRAFT PC

IRQ Interrupt Request vector.Р”Р„t the occurrence of interrupt, the value of the program counter PC is put in high-low order onto the stack, followed by the value currently in the status register and control will be transferred to the address location found in the respective interrupt vector. Signed values are two's complement, sign in bit 7 most significant bit.

Bytes, Words, Addressing: 8 bit bytes, 16 bit words in lobyte-hibyte representation Little-Endian. Page transitions may occur and add an extra cycle to the exucution.

Notably this is not related in any way to the state of the carry bit of the accumulator. Generally, increments of bit addresses include a carry, increments of zeropage addresses don't. Increments without carry do not affect the hi-byte of an address and no page transitions do occur. An increment with carry may affect the hi-byte and may thus result in a crossing of page boundaries, adding an extra cycle to the execution.

6502 emulator computercraft