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Re: UrQ FTCU ground on the intake - What the #@$%.

>    [...]
>    I've picked up a copy of RDH's code disassembly so I could evalu-
>    ate the possibility of adding a PROM address comparator that would 
>    latch on an LED if certain addresses were accessed.  I need to 
>    find out if there are unique addresses for the different shut down 
>    detection mechanisms.  If this would work you could have a light 
>    that comes on when an overboost occurred or one of the other situa-
>    tions that causes the ECU to shut off the fuel pump.  
> I contemplated popping the CPU off and replacing it with one of 
> Motorola's HK05 variants (which tend to come with everything but
> the kitchen sink...), lotsa free outputs (inc serial lines to drive
> LCD displays!!!) . . .

First, I was considering modifying it for a larger ROM, and adding
a RAM chip in the spot on the MAC11b digital board that appears
designed for RAM.

But then, I've also considered replacing the 6800-based digital
board with an 8051-base one I've used for several projects. I like
to use the Dallas DS5000-based 8051 variants, as they have a 
lithium battery-backed-up 64K of RAM, which is partitionable
into CODE and DATA spaces. And, last time I checked, you
could get a version that ran at something like 25 mHz.

Why, you might ask? Mostly, so I could code in a nice system
to capture data in real-time, buffer it, and upload it to my laptop
for analysis.

Who (which chip) handles the A/D on the digital board? Is the
A/D in the Hitachi CPU, or is it handled by the data I/O chip
via control from the CPU? If it's the CPU, then this would
pretty much eliminate the 8051 idea (there are 8051 variants
with A/D I/O, but I'm not an analog guy, so I don't want to go 


-Douglas Hurst Quebbeman (dougq@iglou.com)            [Call me "Doug"]
74 100LS Auto, 77 100LS Auto, 84 Coupe GT, 86 5Kcstq
"The large print giveth, and the small print taketh away."  -Tom Waits