our R31/Z31 ecus use 16K ROM images out of factory. these are stored on 27C128 EPROM chips (128/8 bits = 16Kbytes)
however 27C256 EPROMS (32K) and Pocket Romulators are the choice for most people.
but when you plug a 27C256 into our ecu, the top address line A14 (pin 23) connects to a 5V line and makes only the top half of the chip available to the ecu (addresses 0x4000-0x7fff)
the ecu really sees the image as 0x8000 base address plus 0x0000-0x3FFF. NIStune uses 16K images as the ECU uses 16K images.....
what I propose for 32K chip users is that, if you have a R31/Z31 address file with length 0x4000 (16K) defined in it, if you attempt to open up a 32K file, nistune will ask you if you wish to open the upper or lower 16K. by default this should be the upper 16K
if you save a binary file from nistune however it will be 16K
if you wish to program a 32K eprom with this, i suggest you do the following command from the cmd prompt in windows
copy rom16k.bin + rom16k.bin rom32k.bin
this copies two 16K images of same filename into a 32K image for your eprom programmer. some eprom programmers like my JED one also allow you just to program 0x4000-0x7FFF with a 16K image which is the preferred method
16K / 32K binary images....
Moderator: Matt