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Old 04-28-2007, 01:19 PM
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SVXdc SVXdc is offline
Radio wiring harness guru
Subaru Gold Contributor
Join Date: Oct 2002
Location: Atlanta, GA
Posts: 609
Significant Technical Input Registered SVX
Originally Posted by cdvs
By 'a few things' you mean a dropping resistor, voltage divider or other voltage converter to reduce the vehicle's 12V+ to 5V+ for the RS232/TTL converter linked to above or similar premade device?
The MAX232 chip is somewhat susceptible to blowing up when the voltage goes out of range, so a voltage converter is recommended.

The 78L05 is an ideal part The TO-92 version (package that looks like a transistor) is tiny, very inexpensive (less than $1), and provides more than enough current (100mA), where the MAX232 draws at most 10mA. The larger 7805 is rated up to 1A. The wiring is exactly the same.

pin 2 (orange/white) transmit (rs232/ttl)
pin 3 (blue/white) receive (rs232/ttl)
pin 5 (red/black) to +12V in (choice of above) to +5v out (rs232/ttl)
pin 9 (green/black) ground (rs232/ttl)
Viewing the pins-side of the connector, oriented as in the drawing in my earlier post, the pin numbers run from 1 at the top left corner, across the top to 4, then resume on the bottom left with 5 across to 9.

The car's factory wire colors are different in my '96, as well as on the '96 wiring diagram:
2 Brown/White
3 Green/Red
4 Red/Blue
5 Brown/Red
9 Black/Red

Pin 4 goes to the Cruise Control module. All other positions are unpopulated.

Originally Posted by b3lha
[the CPU is] a newer variant of the old 6502
I thought some of those instructions and opcodes looked really familiar. I played with the Apple ][ way back when.

somewhere I've got a well-used book on 6502 assembler. I knew it would come in handy one day!
It'll only come in handy if you can find it . Fortunately, there's always the Internet.
David C.
1996 Laguna Blue Pearl SVX L AWD
See my home page for SVX radio install/removal instructions and wiring harnesses

Last edited by SVXdc; 04-28-2007 at 03:54 PM. Reason: edited to say I'm referring to factory wire colors
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