The 749 schematics
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Engine: 5.7L V8
Transmission: 700R4
The 749 schematics
I'm been reading the 58 code, and looking at the schematics.
It looks like there are 2 SPI chips on the bus.
One that has its inputs connected to D16 through D11, BRAKE, ACREQ and INJLOOP1. Its output is connected to CTSHI.
The interesting thing is that the other chip has all of its inputs (except one connected to INJLOOP2) connected to ground, and its output is N/C.
I wonder how hard it would be to get at that extra input... does anyone have one that can see if there is a trace attached?
all of the code is in there to use the output on the first chip. The only difference is to set a different chip select line high to access it.
It looks like there are 2 SPI chips on the bus.
One that has its inputs connected to D16 through D11, BRAKE, ACREQ and INJLOOP1. Its output is connected to CTSHI.
The interesting thing is that the other chip has all of its inputs (except one connected to INJLOOP2) connected to ground, and its output is N/C.
I wonder how hard it would be to get at that extra input... does anyone have one that can see if there is a trace attached?
all of the code is in there to use the output on the first chip. The only difference is to set a different chip select line high to access it.
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Joined: Jun 2000
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Re: The 749 schematics
Originally posted by AlexJH
I wonder how hard it would be to get at that extra input... does anyone have one that can see if there is a trace attached?
I wonder how hard it would be to get at that extra input... does anyone have one that can see if there is a trace attached?
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Joined: Jul 2000
Posts: 812
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Engine: 5.7L V8
Transmission: 700R4
It looks like the following filtered inputs are available on the 730/749:
BA3
BB3
BB7
GE10
GE11
GF11
GF12
The wideband patches use GF14 which is listed as MAP2, the only other unfiltered input to the ADC. Does the filtering really matter for the O2 sensor, is it changing that quickly?
It might be neat to use one of the filtered inputs for an engine bay temperature, or a cabin temperature display.
BA3
BB3
BB7
GE10
GE11
GF11
GF12
The wideband patches use GF14 which is listed as MAP2, the only other unfiltered input to the ADC. Does the filtering really matter for the O2 sensor, is it changing that quickly?
It might be neat to use one of the filtered inputs for an engine bay temperature, or a cabin temperature display.
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Joined: Jun 2000
Posts: 998
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From: Tuscaloosa, AL
Car: 91Z, 91RS, '84 Jimmy
Engine: L98, 355, L98
Transmission: 700R, T56, 700R4
BTW Thanks to everyone for updating the Wiki site!
Finding a good way to explain things helps me learn them.Hey if anyone wants a short (4-page) summarized list of the assembly commands for these rigs, I put one together. It's in the incoming section at diy-efi. Look for "68HC11 assembly commands.txt." I figured it would be a good way to familiarize myself with the commands, and maybe help some other beginners out in the process. It's much easier to use as a reference than the 113 pages of appendix A.
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Joined: Jun 2000
Posts: 998
Likes: 0
From: Tuscaloosa, AL
Car: 91Z, 91RS, '84 Jimmy
Engine: L98, 355, L98
Transmission: 700R, T56, 700R4
Err....yeah....zip I meant. It's .txt when you unzip it. 
It's not letting my DL anything from the "incoming" folder. Odd....I'll try putting it up at moates.net/fileman as well.
edit: Works at moates.net, and it really is .txt this time.
It's not letting my DL anything from the "incoming" folder. Odd....I'll try putting it up at moates.net/fileman as well.
edit: Works at moates.net, and it really is .txt this time.
Last edited by TheGreatJ; Dec 18, 2004 at 02:55 PM.
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