Quite honestly, you may not be ready for PCB just yet. You've no idea whether your concept works, to say nothing of your circuit. You need a level of flexibility that you won't get from a PCB. If you've made a mistake in a wire-wrapped circuit, you fix it. If you've made a mistake in a PCB, you've made a mess.

Your basic 805x circuit is simple enough. You need an oscillator, or a crystal and capacitors, you need a reset circuit of some sort, one that works, and probably a way to attach a switch. You need power connectors. You also need those two memory components you mentioned, and you need an address latch. You may even need pullup resistors on P0 in order to feed appropriate voltage to your address latch, if it's CMOS.

You needn't concern yourself with the address/data line arrangement on your SRAM. Only the control signals are fixed. You MUST, however, ensure that your memories are fast enough for your MCU. Keep in mind, that the MCU doesn't generate enables to the external memory until well after the addresses have settled.

In what mode are you planning to operate your parallel port? If you use EPP mode, you have much closer timing control of your programming circuit. Since you can write four bytes in a single cycle, you can't be interruptedin the middle.

RE