>Subject:     Re: Digifant help!!!
>Sent:        12/15/97 4:28 PM
>Received:    12/15/97 1:45 PM
>From:        Don Gibbons, dgibbons@PRESRAY.COM
>To:          Vanagon@GERRY.SDSC.EDU
>
>I once took apart a digifant I ECU to see what PROM chip it used. There
>were no
>non-volital chips other than the PROM chip. There is nowhere for any fault
>codes
>to go. When the ignition is turned off the power to the ECU is turned off
>too.
>There is no power to retain any memory.
>
>But here are the chips:
>
>MC6803U4CP       40 pin          8 bit MCU, No rom, 256k ram, no a/d. 13 IO
>lines
>
>MC6821CP           40 pin          Peripheral Interface Adaptor
>
>CD74HCT373E      20 pin          Tri-state Octal D-type latch
>
>ADC0809CCN        28 pin         8 bit A/D (8 channel MPX)
>
>AM2732A-3DI        24 pin          4K x 8 EPROM
>
>I have the equipment to burn (and copy) PROM's like this but do not have the
>assembler/dis-assembler to do any changes. Note: my ECU had all the chips
>soldered in.
>
>When you know how low buck (compared to today) the digifant brain is you
>can see
>why problems are so hard to fix.

Okay now lets make a new computer for the digifant.  Can I just interface
the old 486 33mhz I use as a door stop?  We can program error finding,
like for a faulty O2 sensor or temp sensor.  We can also have it adjust
timing for older engines or for different driving habbits.
And when the 486 fails in 2 years we can just plug it the ones we are
using right now cause they will be obsolete.  Now if I only find a heads
up display to replace the monitor, and where should we mount the joy
stick (mouse).  Yea and we can have software upgrades every year.

Sorry for dreaming!

Guy
Leaking headed 87 syncro