Thumbwheels & Chip Relocation

[klrv6]

Has anyone made a "home made"thumbwheel chip and if so, do you have instructions for wiring one and parts used? Is there a way I can relocate the chip outside of my ECM?

Thanks

 

[ijames]

I made up a little board that holds two sockets to relocate my chip to the console and to let me use a flash eeprom with multiple chip images for one of the chips. Biggest pain was making the extension cable. I carved out the insides of a RN chip carrier and shaved the sides of a dip header and kind of stuck them together. It's pretty fragile, but I put foam over it and made a hold down plate that screws into the stock hold down plate holes so once it's all together it's okay. I tried a 2' cable or so and had no problems, and I've been running a 4' cable for a year now with no problems. I have a zip file with a writeup and pictures but I can't remember my url, sigh -)). Post if you want it and I'll dig it up tonight.

 

[klrv6]

Zip file instructions

That would be great I too was going to mount this in the console. Thanks!! So are you able to select which "prom" image you want to run from? I have many proms I would like to put on a single chip. Once I get DirectScan I think I would wear the ECM socket out.

 

[chris]

The flash eeprom would be interesting to see.

 

[ijames]

Okay, hope this link works: http://members.verizon.net/carl.ijames/ChipFliprI/ChipFliprI.zip You should be able to right-click on it and save to a file. The next step up past 24 pins is 28 pins. I cheaped out and used a 2764-equivalent (or a 2764 itself if you want eprom) DS1225Y flash chip, tied the top three extra address lines high and put a switch to select the lowest address line past a 2732. That lets me select between two images and not have to mount a thumbwheel switch. In hindsight I should have used the tw and a 27256-equivalent flash because they are only a couple of $$ more than the ds1225 (about $22 each), which would give eight images. My board layout needs tweaking, too, to give a little more room around the sockets and I should put a ring terminal on the ground braid on the cable and put it on a stud, to really take the strain off the dip header connector. Anyway, it works which I thought was okay for a first prototype . I put it in a little plastic box with rubber feet on the bottom, which sits on my transmission tunnel since I don't have a console. I'll repeat, the cable is the painful part if you do this. You might even want to consider replacing the socket in the ecm with something more convenient. Anyway, read the docs and post any questions. I had three boards made, built one for me, sold one, and have one left somewhere around here. I did the layout with pcbexpress so the three boards were between $60 and $80, I forget exactly.

Wow, tested the link and it actually worked . Just click on it and you should get asked what to do with it; you don't need to right click after all (I'm such an intentional neophyte about html ).

 

[klrv6]

Switch instructionS & 27c256 info

Where can I find more information about burning the 8 images to one chip?

Will a 27c256 do the same thing as a 27256?

Thanks!

 

[chris]

programming for 27256

Try this.............

1.select the chip by clicking on the chip number. (27256)thumbwheel and 2732 for single program chip.
2.put chip in the programmer and select "blank check". If not blank erase or get another chip.
3.If blank select "start of device" and enter "00000" then select " end of device" and enter "00FFF" and enter.
4. Select "Load Buffer" and use your directory to load Bin file for position 0.
5. Select "Program Device" to program position 0.
6. Select "Verify Device" to make sure the program took hold.
7. Now your ready for the other 7 position. Starting with step 3 entering the follow numbers for each position.
1- 01000----01FFF
2- 02000----02FFF
3- 03000----03FFF
4- 04000----04FFF
5- 05000----05FFF
6- 06000----06FFF
7- 07000----07FFF
For the 16 position, you continue with:
8- 08000----08FFF
9- 09000----09FFF
10-0A000----0AFFF
11-0B000----0BFFF
12-0C000----0CFFF
13-0D000----0DFFF
14-0E000----0EFFF
15-0F000----0FFFF

Hope this helps.

 

[klrv6]

One last question?

What pins do I connect from a 2732 to the thumbwheel switch?

Will your chipflip example work for an 8X chip?

Thanks for your time Chris!!

 

[ijames]

For a 2732 you don't need a thumbwheel - it's the stock size eprom that holds one 4 Kbyte image. His stacking example will work for 8x and 16x sized flash chips. There's also a freeware program that started as gmecmedit and is now called TunerPro which uses the same .ecu definition files as promedit and WinBin, which can also stack multiple chip images into one large bin - see http://www.supportfitness.com/mark/tunerpro/. My ChipFlipr will work with an 8x 27256-compatible chip with a very few mods on the traces to bring out those address lines to a thumbwheel switch.

 

[klrv6]

Chip mods?

What would the mods be to allow other addresses?

Thanks!!

 

[JaBoT]

If you need to compile 8 bins on one 29c256 or 27c256 use this bin compiler program by Craig Motes.

Bin Compiler

Use setting 8x4k on a 29c256.

This rest is self explanatory