[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: EDD Plus Card



Scott Alfter wrote:
In article <473c6957$0$19735$4c368faf@roadrunner.com>,
Bryan Parkoff <nospam@nospam.com> wrote:

Do you know where I can find to buy EDD Plus Card? It is rare and not found on eBay.

  Info on http://www.apple2info.net/hardware/edd/edd.htm


At this point, it'd probably be easier to build your own than to wait for
one to turn up on eBay.  The page you linked includes a reverse-engineered
schematic; all that would remain would be to do the layout, board
fabrication, and assembly.

Although the "schematic" given is more like a "pictorial" than a
schematic.  It requires conversion to a conventional schematic
with logic symbols to understand what's going on.

My understanding (without having done the step above) is that it
is simply a shift register, sampling all the read data at 2MHz (?)
so that the program can interpret the complete data stream, including
all zero bits.

-michael

NadaPong: Network game demo for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."