[Coco] DriveWire 4 and Linux serial port

[Steven Hirsch]

On Sun, 8 Feb 2015, Gene Heskett wrote:

> While you may have the Pi handy, as you've seen, real X support is lacking. 
> You would I suspect, have a lot better luck using the Beaglebone Black, 
> which does have built in HDMI output, just plug the cable into the connector 
> on the Pi sized board.
>
> A branch/fork of LinuxCNC called machinekit is happily running several CNC 
> machines right now, and you cannot tell from looking at the GUI that it is 
> not an X86 based machine on the far end of the video cable..  All it needs 
> is an I/O cape (stacked buffer/connector breakout board) to bring out the I/O 
> in a format that is easier to connect to in the field. The thing actually has 
> a large group of sub-processors that can generate step-dir signals at 20 
> mhz+ rates while the cpu is off doing something else.
>
> $70 for the basic board, which may be all you would need except perhaps a 
> usb-serial adaptor to connect dw to the coco.  And stay the heck away from 
> Prolific chiped adaptors, use FTDI based instead.  I have had both here, and 
> I am in fact using an FTDI serial adaptor to get to a db9, and that in trurn 
> is plugged into the coco's bitbanger.  Home made cable.

And, for extra credit, the BeagelBone Black CPU has a pair of slave 
processors called PRUs (programmable real-time units) that run at 200Mhz 
with 100% deterministic timing.  David Gesswein has designed a BBB cape 
and software suite that lets you not only read and write data from MFM 
format hard disks, but also turn around and emulate an MFM disk using a 
cpatured image!  There are many classic computers that require MFM disks 
and most have either been ground up for scrap, failed or are just about to 
fail.

http://www.pdp8online.com/mfm/mfm.shtml

In the course of my (relatively minor) code contributions to this project 
I have developed a healthy respect for the BBB.  Truly an "industrial 
strength" alternative to the rPi.

Steve


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