RomRaider

I know there's no way to flash these ECUs, but is it at least possible to extract the data and display the maps in RomRaider?

Engine is 6-cylinder normally aspirated, type EG33. Transmission is 4EAT.

CPU is M37791
This file is a dump of the whole 16-bit address space.

0000-00FF is IO
1000-14FF is RAM data (14FF downwards is the program stack)
8000-8FFF is ROM data (possible 16x16 tables at 0x8120 and 0x8e20 ?)
9000-FFCF is ROM code
FFD0-FFFF is Interrupt vectors
The rest of the address space appears to be unused.

If there's no way to flash it, what would be the point? Where did you get it?

I guess the ECU doesn't use a modern processor including Flash memory and make use of an external ROM memory chip as the 1995-1998 WRX do.
Saying that, you can still read the whole memory to file, modify it (assuming you have def file), and programm a new ROM chips. That's what some here do with 1995-1998 cars. The ROM (27C512) is soldered onto the PCB (don't know for the SVX ?), you will have to extract it and replace it with a DIP receptacle.

You can't flash it, but you can burn an EPROM and pop it in the empty socket on the board. Then you cut a resistor and the EPROM will take precedence over the original ROM.

I downloaded it from my car through the yellow OBD1 subaru select monitor plug using an RS232 to TTL converter.

I have managed to disassemble the code using an M37710 disassembler that is part of the MAME arcade machine emulator project.

Haha, sorry, I think its cool/funny you're leveraging mame

I still haven't figured out how the JECS ECU works, but I have found the fuel, timing amd knock correction tables.

I've created an ecu_defs.xml file with the information that I have found so far. It should also work for other Subarus using the JECS ECU.