NSSBC : the why

I'm an 8 bit man. I did program the 8086 in assembler, so that is full blown 16 bit code. Yet, the 8086 is just a beefed up 8 bit processor. Only in name it is 16 bit. Earlier this year I thought the ARM LPC family was my new cup of tea. Real 32 bit processors that can be used and programmed like an 8 bit PIC. ARM and PIC share a common denominator: RISC. I know the PIC and it's RISCyness. So the step towards the ARM seemed logical and natural. But it wasn't.
The ARM is a disaster. The processor's only strong point is the fact that Apple use it in their overpriced and underfeatured bling bling gadgets. The CPU is engineered by a separate company that lease the rights to use the ARM core to hardware producers that are willing to pay the price, like Philips, Samsung and others.

Result: too many chips with similar cores that are all totally different. There are so many datasheets that you cannot find anything that is not already incorporated in a gcc toolchain. And when I did find the things that I was looking for I discovered that this 32 bit RISC machine is closer to an 80386 CISC machine than to any RISC processor at all. The first ARMs may have been RISC but that's a long time ago. These processors are way above the level for enthusiasts like me.
So after a short ARM detour I came to my senses. No 32 bit RISC for me. I'm an 8 bit man. And as I grew up with Zilog, Zilog it will remain for the rest of my life. I tried to sell some of the Z80 stuff I had. But only bounty hunters reacted on Ebay. So I decided to give the Z80 chips a second chance. I want to use them in an SBC that is yet to be built: the NSSBC or the Not So Single Board Computer.


NSSBC : the what

I tried to find some modular Z80 Single Board Computer like they were made by Ampro in the 80's. But they're all gone. So I set out to make my own. In the style of the British Z80 boards of the 80's. And with as many spare parts that I still have around in my toolboxes. The idea is to make one computer that can mimmick several other 80 style british micro's:

The ROM's may need a serious rework, but the general idea is to have lots of ROM images for each specific micro in a 16 KB bank of a large Flash ROM. By means of a bank of DIP switches, a specific computer mode is selected. So, the hardware of the computer must be as flexible as possible and the system I have in mind right now should at least be: All of it with the following in mind: As of now, 21 March 2011, the first version of a CPU module is ready. It is created with Eagle, but the target is to move development towards the gEDA toolchain. Eventually.


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