JamMan Special ROM V0.2 Users Guide
EEPROM <go back to table of contents>

The new Stec Special ROM for the JamMan provides support for a EEPROM which allows most system parameters to be saved then restored on system power up (nonvolatile backup). The original JamMan was designed to use a EEPROM for storage of parameters but the part was ultimately left off to keep the price of the product down and software support for it was never added to the product (until now). To add this feature to your JamMan, refer to the "How do I get the EEPROM?" section below.

Storing Parameters
When changes are made to system parameters that you would like to save as defaults on power up, press the STORE button (previously PARAMETER button). The display goes blank while the data is written to the EEPROM. When the display returns, the system parameters have been stored. The next time the system is power cycled, the parameters will return to their settings when you STORED them.
 
NOTE: Loops are cleared when a store operation is performed. I'm going to try to eliminate this in future versions but be warned.

Whats Stored?
- Channel Level (all Channels, all Pages)
- Channel Pan (all Channels, all Pages)
- Click Level
- Slap Level and Time
- Dry Level
- Divide
- Feedback
- Audio Threshold
- "Learned" MIDI controllers
- MIDI Channel
- Number of Beats

How do I get the EEPROM?
The EEPROM can be added to your system in at least three ways:
1. Send it to Stec for an update ($75)
2. Add it yourself
3. Take it to a local repair tech to add it.

The part itself is the NM93C66EN, a 4K BIT serial EEPROM in an 8 pin DIP package made by Fairchild Semiconductor and is available from most IC dealers (Digi-Key, etc..). The part is also available from Stec for around $10.

Stec Updates
Send your JamMan with a cheque for $75 to Stec at the following address:

Stec c/o Bob Sellon
42 Andover Rd
Billerica, MA 01821

We will install and test the EEPROM, as well as test the basic operation of the system. (this is also the only way I can currently make any money off of any of this so this generally helps to keep JamMan development alive. Sort of a "Support your insane JamMan programmers who can't leave well enough alone" foundation.)

Add It Yourself
It turns out, there's really not much to it:
 
1. Get your hands on a 93C66 EEPROM, an 8 pin DIP socket and a 0.1uf capacitor.
2. Remove the cover from your JamMan (remember, they use those funny screws).
3. Suck the solder out of the holes for U7 and C12.
4. Place the 8 pin DIP socket into the holes (checking the pin orientation)
5. Place the 0.1uf cap into the C12 holes.
6. Solder in the socket and the cap. 
7. Put the EEPROM into the socket.
8. Replace the covers.

Not too bad but you should have some previous experience soldering PC boards (not just cables) so you don't damage the board or create solder shorts (globs of solder connecting points on the board that should not be connected). You also need to be real careful of static damage, particularly in the winter when it's dry.

For tools, you will need a soldering iron with a fine tip, solder (the Radio Shack kind with no acid will do), a solder sucker or "Solder Wick" (to remove the solder from the holes), the special screw driver to remove the cover.
 
NOTE: I always install a socket whenever I do this kind of update, though it's not technically required. I consider it cheap insurance in case I get a defective part or install it wrong, I can just pop the part out. Most parts on the JamMan are soldered in to keep the cost of the product down. You can install the EEPROM without the socket but be warned that you can only desolder components so many times before the etches on the PC board become damaged (even if you are an expert solderer). 

Take it to a local Repair Tech
This is basically the same as sending it to Stec except you bring a printout of this page along so the tech will know what to do. This is a good option if you have a good tech and you can't afford to go without your JamMan for a few weeks.