Reading the old C3's.

[Ludis Langens]

Ross Myers wrote:
> 
> I know Ludis has those ROMspit BIN's on his website for getting the internal
> ROM data out of the old C3's, but would it also be possible to connect a
> plug to the 40pin port (Used for testing by GM?) on the main board then run
> each Data and Address line to an EPROM Reader as a 27c512 would appear and
> read every bit of data from $0000 - $FFFF?.

If you HALT the processor, if will declare the BusAvailable, and stop
driving the address lines.  R/~W will go high, and E will continue to
cycle.  If you supply an address, you can read any memory location. 
However, the data bus will only be driven while E is high.  Unless you
can syncronize the EPROM reader to E, you'll need a latch to hold the data.

> May seem the hard way, but if this is a standard pin out on the edge
> connector it may just be O.K. (I'd like to read out 1226026 I have).

So far, the 40 pin connector has used the same pinout, but I've never
checked anything as old as the 6026.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/