Hi All,
The N8VEM home brew computing project is still going. There are about 50 members or so of the N8VEM Google Group and numerous SBCs have been completed. I've sold many of the PCBs and have lost count somewhere along the way. All of the SBCs which have been built and I know of are now working. There were a few builders that had some problems but we seem to have worked through those.
I still have PCBs available for the SBC so if you are interested please contact me. If you are interested in expansion, there is also an ECB backplane available for adding peripherals. You can build your own or add peripherals as they come available.
There has been some good news recently as the ECB bus monitor is now working to help builders debug hardware and software. It is supposed to operate a bit like a Jade Bus Probe but is for ECB instead. It seems to work although I haven't completed my own unit yet there are some builders with working units. Here are some N8VEM blinkenlight videos of the ECB in action:
From my friend Rolf:
http://www.hd64180-ecb.de/assets/n8vem/N8VEM_BUS_0001.AVI
http://www.hd64180-ecb.de/assets/n8vem/N8VEM_BUS_0002.AVI
From my friend Clive:
http://n8vem.googlegroups.com/web/ECB+Monitor+clip+.wmv
If you are new to home brew computing, some highly motivated builders have produced excellent introductory webpages on how to get started.
James excellent work here at Instructables:
http://www.instructables.com/id/Robot_Brain_Build_a_single_board_computer_in_an_e/
Oscar has written this wonderful introductory piece:
http://www.geocities.com/homeofoscarvermeulen/n8vem/n8vem.html
I have PCBs available for the SBC, the ECB backplane, and the ECB bus monitor. They are $20 each plus shipping. Shipping is typically $2 each in the US and $5 overseas. Multiple boards per order reduces per unit shipping costs but has to be determined depending on weight.
There are two more boards in development; the prototype board and the Disk IO board.
The prototype board is a custom ECB board specifically designed for builder prototyping. It has a bus interface with signals exported to builder pads, programmable high nibble IO address decoding with builder extension pads, full buffering of address, data, and incoming control signals. Outgoing control signals are available to the builder. VCC and GND rails are provided for short connections to the ICs. Everything is labeled on the prototype board for easy access. It is in final PCB layout right now and should be going to manufacturing soon pending final review. You don't have to use this board to make your own prototypes but several builders have requested this unit so I designed it. Hopefully it will make home brew peripherals easier to build.
There is also a Disk IO board in work with IDE and and FDC based on the i8272. I built a working hardware prototype from protoboards on my bench and some initial testing software which provides the basic functions (seek track, recalibrate, sector read, sector write, format track, etc). I am fairly sure the fundamental design is solid. Presently I have captured the schematic in KiCAD and am doing a PCB layout. The PCB is in the auto-router optimizer right now but due to complexity of this unit it will probably be a while before it is released to manufacturing. I would like to get some additional reviews of this design due to its inherent complexity as well.
Several builders have their own peripheral projects in work as well ranging from LCD displays, SD reader/writers, wireless links, and various other things that are probably better described by the builders themselves. Here is a picture of an LCD display project Clive made that is just great and made me smile when I first saw the picture:
http://n8vem.googlegroups.com/web/LCDisplay1(top).jpg
So if you are interested in building your own home brew Z80 CP/M computer you may be interested in checking out the N8VEM project. Builders of all skill levels are welcome and I will be glad to help out as best I can.
Thanks and have a nice day!
Andrew Lynch