Multi-Chips? How do they work?

[Strahd_Zarovich]

Like the title say's how do the multi chips work. I an learning to program ROM's now and like the idea of haveing one chip with my race and street settings on it. I only need those two settings. While mybe three with the third one for anti-theft.

 

[granatl]

Conceptually, here goes. The "extra" pins on a 27256 or 27512 are address lines. So toggling those address lines can put you in a different 4K segment (and lucky for us that the 2732 is a 4K EPROM). So if you create a ROM file with 8 different 4K images back-to-back, you can write them to the 27256, and then pull the address lines to get into the higher segments.
I know almost nothing about EE, so it would take someone else to tell you how to get the voltages right for those pins.

You would probably want to put the anti-theft in with your street chip. I've seen that Fry's sells 2764's, so if you just used the one extra address line, you could get your 2 in 1 chip; but then again, you'll still have the fun of getting a chip with extra pins to work in our socket.

HTH

 

[2QUIK6]

Just concatenate the 8 different TR programs in DOS into 1 file, then burn that 1 file onto the 27256 chip, and plug it into an 8 position thumb wheel, you can get the blank thumbwheels from Casperselectronics.com for about $80.
You can also then buy the 27256 chip that is electronically erasable so you don't have to use the UV light anymore...much quicker and easier....I forget the number, its something like AT27256???

You'll also want a valet chip by setting fuel cut-off constant to 2700 rpm and boost scalars to 0%.
Then maybe a couple of versions with slightly more timing.