EPROM emulator boards

[steve ravet]

"David A. Cooley" wrote:
> 
> -----Original Message-----
> From: Terry/Carol Kelley <terryk at foothill.net>
> To: gmecm at esl.eng.ohio-state.edu <gmecm at esl.eng.ohio-state.edu>
> Date: Tuesday, March 30, 1999 11:32 AM
> Subject: Re: EPROM emulator boards
> 
> >Hi Dave,
> >
> >I'm interested! I tried the LDTI emulator. It works, but the engine is
> >likely to die when the code is changed. If you fast enough, it will stumble
> >and keep going. At idle, it almost always dies.
> >
> >I could interface this new one to GMEPro.
> 
> That would be cool!
> just a new menu option for "activate changes"!
> I've modified the circuit I found by adding battery backup to the RAM
> (62256's).  I need to look at the software they have and see if it let's you
> byte-poke or if you have to do a full dump each time...  I guess new
> software could be written to do one location at a time!

According to the schematic you have to push the reset button which
resets the on-board counters to zero.  Every byte sent over the serial
port increments the address counter by one.  So you have to start
writing at zero up to the highest address that you want to modify.  Plus
there is a switch for "program" versus "emulate" modes, while you are
uploading the ECM is locked out.  Transmit speed is set by the clock you
choose, so it can run at any baud rate you want.

This is not an "edit while you drive emulator".  It seems like it would
work fine, but you will have to stop the engine while you upload a new
program (Or you can upload the the engine will die for you :-).  Just
want to make sure everyone knows what they're getting.

--steve

-- 
Steve Ravet
steve.ravet at arm.com
Advanced Risc Machines, Inc.
www.arm.com