This is an old post, preserved for reference.
The products and services mentioned within are no longer available.
I'm sure you've all heard of the RC2014, it's a modular Z80 computer system available from seller 'Semachthemonkey' on Tindie. A great little system that makes it easy to build and expand a Z80 based system. (or even a 6502 system as the base is very adaptable).
backplane and other modules can be found on the rc2014.co.uk website.
Z80 CPU ModuleFull details here. Like all of the other modules here, there is no decoupling on the boards, only on the backplane. I'd like to see the traditional 100nF on each chip, I think that has happened on the later modules.
8K ROM ModuleFull details here. As supplied, it came with a version of BASIC adapted from the NASCOM computer by Grant Searle - more details on his site. This is fixed 8K ROM decoded to the address range 0x0000 - 1FFF. There is a later module which allows bank paging, which is one of the new ones I have ready to install.
32K RAM ModuleFull details of the 32K RAM board here. If I remember correctly, this is another one of the boards where I started with a 74LS32 and changed to a 74HCT32 as I found some RAM chips (the Alliance AS6C62256 shown) didn't work with the LS chip, but other 62256 chips were fine.
Serial IO ModuleFull details here.
The RC2014 in use
RC2014 MiniRC2014 Mini. This is basically all of the above on a single board. It can be used standalone, of there is space to fit a 40 pin connector on the side to add a single module, or a backplane full of modules. This one is also driven via FTDI serial cable, or you can use the RC2014 Universal Micro Keyboard.
Minstrel ZX80 clones.
Update:a combined Z80, clock and reset module.
2022 Update: RC2014 continues to be very popular, they can now be ordered from the sellers new store z80kits.com