Hello everyone,

I have finally decided that it is time for me to build my second computer. My first was when I was in high school. The physics teacher also taught computer engineering in which we build a sbc which was similar to the kim-1. I have decided that I want to use a 65816 for the project, but I have a few questions about it, and im looking for some suggestions for some of the different parts. I did my best searching around the forum, so hopefully I won't be asking anything that has already been answered.

My first question is on addressing, since the data lines are also used to address the top 8 address lines i figure I will use an eight bit latch synced to the clock. I was wondering if there are any major pitfalls, or if there is a better way to do it?

Secondly, I have a question on peripheral access. What should I use it interface to the '816? On my '02 project I used a 6522 but that only runs at one mHz(and reliably at 2 mHz) but I have a feeling it wouldn't fair well at the 14(?) mHz that the 65816 runs at. Other thing which I would like to have on this machine, serial port for my console, keyboard and mouse ports(so 2 ps2 ports, which are just more serial ports) and a vga out to connect it to a monitor. On the system that I have already built the system used bit-banging for the rs-232 communication, however, Id like to use a UART. Other than that im probably going to have 32 k of low memory(bank 0) , then probably 512 k of high memory(bank 1-x), and then probably some video memory(bank x- y).

The last question I have concerns video. Does anyone know of any good graphics chips, idealy modern and available. Id like to be able to run something like contiki from this machine.

Thanks everyone, and if I didn't make something clear, I can clarify it.

Thanks again,
Michael Moran

The 65c22 is also available in 14MHz.

Remember you don't need to latch or decode any high address bits you're not using. If you only use bank 0, you don't need to latch any high bits at all. (The '816 still gives a lot of advantages even if you don't need more than 64K address space.) For the amount of memory you mention, you'll want to latch 4 or more of the high bits.

There are a lot of UART options. One I kind of like is the Maxim MAX3100 14-pin-DIP UART which is also IrDA-compatible. It uses the SPI which is very easy to interface through a 65c22.