Re: Selectable chips & boost programming

["Dave Zug" <dzug@delanet.com>]

I posted this before, and its not really as nice as the selector chip but
its as creative if not more...and its the only truly unique thing I came up
with on my own...

The turbo GP cal pak has alot of addressable free space on the 27c256 eprom.
I basically copied and pasted the spark table in the free upper chip area
and slipped in a JSR after the checksum routine that set a fre RAM bit (A0
byte is completely free if I remember the number right) based on the TPS
being above or below 50%.  in the program where the spark table location is
set (in X i believe) I inserted another JSR that went to a routine to reset
X to the new location if location A0 bit 0 was set.  this effectively let me
have 2 spark tables, one normal (below 50% tps at key-on time) and a high
octane spark table.  nothing to say I could not have had 4 of them. I did
this without a re-compiler by moving the code I displaced with the JSR
instruction into the subroutine (long as there are no offset instructions
outside the new location or other things to booger it up, this works)

I was thinking this technique could be used to have a completely stock
looking cal pak and the selection between ENTIRE PROGRAMS could be done with
the TPS in combo with the neutral switch for more choices.

To a question:  Does anyone have a memory map of the 727, 165, 730, ..,.. ?

thats probably gold, bet that would be alot of work to draw up. how bout a
map showing the "free" blocks just beyond the factory program?

> > > >
> > > > >Don't have anything in hardcopy, but it used a 27C128 chip stock,
so
> I used
> > > > >a 27C010, mapped all the similar address, Data, power and control
> lines to
> > > > >a 28 pin plug so the plug looked like a 27128 to the ECM. Took the
3
> > > > >additional address lines and ran them to a BCD thumbwheel switch,
and
> the
................

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo@lists.diy-efi.org