The ATMEL AT29C010 chip is a FLASH-ROM chip with 1Mbit(~128kb) of memory. It can be found in old Pentium I&II computer motherbords. This chip will work in ECUs, but require pins to be moved around/altered due to them being a different pinout than either 27 C256 or 29 C256 chips. When writing/burning the program, you need to specify the start address, where your ECU looks at.

Datasheet for an Atmel 29C010 (PDF)

 name:         29C010A
 function:     128k x 8 CMOS Flash Memory
 package:      DIP-32,32
 pinout:

      +------()------+
  NC  | 1          32| VCC
  A16 | 2          31| WE
  A15 | 3          30| NC
  A12 | 4          29| A14
   A7 | 5          28| A13
   A6 | 6          27| A8
   A5 | 7          26| A9
   A4 | 8  29C010  25| A11
   A3 | 9          24| OE
   A2 |10          23| A10
   A1 |11          22| CE
   A0 |12          21| I/O7
 I/O0 |13          20| I/O6
 I/O1 |14          19| I/O5
 I/O2 |15          18| I/O4
  GND |16          17| I/O3   
      +--------------+