68000 from car

evildragon · Post by **evildragon** » Mon Jul 09, 2007 11:34 pm

My car's (94 chevy) computer, has a MC68000 inside it. It's on a socket, and has the same pin-count as the one in the Genesis..

Can I take it out, and install it in my Genesis? I ask this, because I'm out of MC68000's, and I want my Genesis to have that CPU instead.

I would then put the SCN68000 in my car (that came out of the Genesis).. This will work, right?

the only difference, is the car's CPU is 12MHz...

8bitwizard · Post by **8bitwizard** » Tue Jul 10, 2007 2:23 am

Unless your crappy SCN68000 is a 12MHz version, I wouldn't do it. I don't think you want an overclocked crappy CPU in your car. The SCN68000 doesn't overclock very well, does it?

evildragon · Post by **evildragon** » Tue Jul 10, 2007 2:24 am

8bitwizard wrote:Unless your crappy SCN68000 is a 12MHz version, I wouldn't do it. I don't think you want an overclocked crappy CPU in your car. The SCN68000 doesn't overclock very well, does it?

well, they supposedly don't overclock well, but it was discovered that it was the motherboard that can't overclock..

i then assume that the SCN68000 could then overclock...

8bitwizard · Post by **8bitwizard** » Tue Jul 10, 2007 3:06 am

But has anyone put an SCN68000 into a board that could overclock?

evildragon · Post by **evildragon** » Tue Jul 10, 2007 3:14 am

8bitwizard wrote:But has anyone put an SCN68000 into a board that could overclock?

no, i don't think so, i was hoping someone has...

anyway, even if it couldn't, can't i just underclock my cars CPU? I mean, does it REALLY need 12MHz? I can't imagine a '94 car needing so much..

Jorge Nuno · Post by **Jorge Nuno** » Tue Jul 10, 2007 4:38 am

Is the CPU running @12Mhz? or it's just rated @12Mhz?

It may be rated for 12Mhz but runs only @8Mhz...

Just swap CPU's and see what happens... you wont burn/damage anything

evildragon · Post by **evildragon** » Tue Jul 10, 2007 7:03 am

Jorge Nuno wrote:Is the CPU running @12Mhz? or it's just rated @12Mhz?

It may be rated for 12Mhz but runs only @8Mhz...

Just swap CPU's and see what happens... you wont burn/damage anything

just used an oscilloscope on it with the car started.. it's running the CPU at only 5MHz...

why so low?!

jobro · Post by **jobro** » Tue Jul 10, 2007 9:29 am

I would say it is to be secure that the cpu wouldn't melt. I'm no car owner and thus have very limited experiences, but that's my thought.

TmEE co.(TM) · Post by **TmEE co.(TM)** » Tue Jul 10, 2007 11:54 am

In my MD1 clone, the 68K was rated 12MHz while it ran at stock speed of MD (7.60MHz)... maybe the 12MHz version was just cheaper at that time ?

evildragon · Post by **evildragon** » Tue Jul 10, 2007 12:19 pm

don't know.. i honestly never even heard of a 5MHz 68000..

btw, update on the SCN68000 in the car: The car stalled when heading to the gas station.. computer brought up an error code, which was a mis-timing on the cylinders..

it appears the SCN68000 can't handle it...

8bitwizard · Post by **8bitwizard** » Tue Jul 10, 2007 2:39 pm

PIX PLZ

evildragon · Post by **evildragon** » Tue Jul 10, 2007 2:50 pm

pics of what? The car PCM? I already put that back into the car, I'd have to pull out the air filter and everything again..

inside the Genesis? it looks no different than any MC68000...

evildragon · Post by **evildragon** » Tue Jul 10, 2007 3:46 pm

here's a video of it running on my LCD monitor/TV..

connected via Composite.. (my video capture card don't like 240p, and my DVD recorder only takes in true Y Cr Cb input)

Sony Handycam 8...

http://blackevilweredragon.spymac.com/carcpugame.mp4

The video starts with me figuring out if it's on or not (the camera hasn't been used in atleast 10 years!), and then I go to the LCD, reset the Genesis (reaching down with camera in other hand), and then aiming at LCD.. it then ends with me figuring out how to turn it off, LOL!

you may hear a weird "winding/clicking" sound, that's the cameras focus motor...

The LCD has it's overscan set JUST at the picture on the Genny.. i didn't want ANY border visible on the picture..

8bitwizard · Post by **8bitwizard** » Tue Jul 10, 2007 8:32 pm

evildragon wrote:pics of what? The car PCM? I already put that back into the car, I'd have to pull out the air filter and everything again..

How convenient. Nice troll. You really had me there, even though I knew better that not only would a car company not pick a 64-pin DIP for a car computer (by 1994 even Sega was using surface mount 68000), but it would also be potted in epoxy just to keep it from rusting, etc. And it certainly wouldn't be socketed.

http://blackevilweredragon.spymac.com/carcpugame.mp4

So how does that prove that you ever did anything to your car?

evildragon · Post by **evildragon** » Tue Jul 10, 2007 8:40 pm

8bitwizard wrote:
evildragon wrote:pics of what? The car PCM? I already put that back into the car, I'd have to pull out the air filter and everything again..
How convenient. Nice troll. You really had me there, even though I knew better that not only would a car company not pick a 64-pin DIP for a car computer (by 1994 even Sega was using surface mount 68000), but it would also be potted in epoxy just to keep it from rusting, etc. And it certainly wouldn't be socketed.

http://blackevilweredragon.spymac.com/carcpugame.mp4
So how does that prove that you ever did anything to your car?

do check GM Power Train modules, they don't epoxy it, and they do use standard parts..

Look up the one for LT1 engines, and be surprised at the fact they DO use MC6800 parts in them..

this is one that goes to some LT1's (it's an even modern replacement)
http://www.autoblog.com/media/2006/04/LT1-PCM.JPG

so no, not trolling... sorry you have to be insulting..

I don't know why i would have to prove this, anyone that even looks at their car computer would see the standardized parts used in those things...

oh, wanna know why GM wouldn't have wanted to use a surface mount if they didn't have to? the DIP's would be more mechanically secure to the PCB during operation.. not to mention, the downclocking alone could possibly have been for what was suggested, better reliability under temperature ranges, which would make sense...

another car computer: http://www.turborx7.com/images/Technical/ECU2cr.jpg

http://www.team-integra.net/images/BAEC ... natomy.jpg

http://www.j-k-tuning.com/images/ECU/ECU_1.JPG
(that's the kind of socket my car has.. not the same, but that's the kind the CPU has, alone with the foam back padding)

seriously though, I already gave up hoaxing well awhile ago.. anyone who knows me personally would know I wouldn't want to do it again, it was too much stress..

i mean, even if I wanted to hoax this, what exactly would be the point?

EDIT: Oh, and being a replacement PCM for my car, they used Socketed CPUs with the case having pressure pads to hold the CPU in place.. They ALSO used sockets, so if the CPU failed, it can be easily replaced without replacing the PCM, as had happened to me before...

EDIT: and yea, read about the LT1 PCM's first.. from the site for the first picture.. this is STANDARD GM part: "The PCM in the LT1 uses a pair of 8-bit microprocessors that based on the venerable Motorola 6800, but contain custom features specific to engine management. Several application-specific integrated circuits (ASICs) are provided to interface the microprocessors with the various inputs and outputs of the PCM, while 160kB of Intel Flash non-volatile memory and a small amount of RAM serves to store the application code and calibration constants for the system. Newer ECMs and PCMs make use of significantly more powerful 16- and 32-bit processors (such as Motorola's PowerPC) and larger amounts of storage and memory (several megabytes in newer powertrain modules)."

mine was a replacement from about 9 years ago. It was fitted with a DIP.. I have no control over who built it, because many manufacturers make PCMs, and build them their own way.... So don't come in here calling me a troll, when I am not trolling, and you have no proof, especially when simple research would yield information stating that I am correct...