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> SYSCALL System Call Rabbit 3000A/4000 Instruction

> Opcode | Instruction | Clocks | Operation
> ED 75 | SYSCALL | 10 (2,2,3,3) | SP = SP-2; PC = {R,0x60}

> Flags | ALTD | IOI/IOE
> S | Z | L/V | C | F | R | SP | S | D
> - | - | - | - |  |  |  |  |

> #### Description

> Pushes PC on the stack and then resets the PC to the interrupt vector address represented by IIR:0x60, where IIR is the address of the interrupt table and 0x60 is the offset into the table. The address of the vector table can be read and set by the instructions LD A,IIR and LD IIR,A respectively, where A is the upper nibble of the 16-bit vector table address. The vector table is always on a 100h boundary.

> SYSCALL is essentially a new RST opcode, added to allow access to system space without using one of the existing RST opcodes. It will put the processor into System mode and execute code in the corresponding interrupt-vector table entry.

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