Quote Originally Posted by wowzer View Post
i have not tested the 28c010 to see if it is compatible with the existing boost button flash routines. i think miles indicated in an earlier post that the BB 4play cannot be flashed other than using a chip burner(?).
. it appears that on most of the ecus we are looking at that the a15 address line is not used purely as an address line but as a chip enable toggle. miles will have to confirm/clarify that.
Rob L has documented the programming of the 28C010 FourPlay. You turn the switch to the position you want to write or read. MPTune programs the 32K space selected. I have not tested the 28C010 FourPlay as we are interested in the newer and faster 39SF010 but also should work as Morris described above.
The A15 conversation is confusing but let me give it a try. Normally we use an 27C256 EPROM at 32K with no A15 pin. Let try a larger chip such as 27C512 has an A15 at pin#1. This is the 16th address line on the 27C512 and toggles either the lower or upper 256 of the chip (using 0 or 1). each 256 is 32K. If we had an on or off switch on this A15 line we could switch from the lower to upper 32K at the turn of a switch. This is a DualPlay. Pretty cool Eh? What happen if you double the memory again....FourPlay

Now on the flash modules we have a control line on a PCB pin called A15 but does not connect to the EEPROM A15 so what give???

The simple explanation is the programming A15 have ZERO to do with the EEPROM A15. So lets forget about the EEPROM A15 for the reminder of this discussion.
When we program or flash a chip we want the chip not to be enabled, so this is done with a special pin on the chip called Chip Enable or CE. This line is ultimately controlled by pin 35 on the ECU processor and sent to the flash board, If you lookup the pin name it is PD7/A15. Voila here is the name used. I would have named it PD7. https://neuron.eng.wayne.edu/auth/ec...s/image002.jpg


Thanks Morris for the hard work!