My xecuter 2 mod chip has two banks of 1m flash space (two banks @ 512k each)
The problem arises because the cromwell bios i downloaded was only 256k. I found that it just needed “padding out” so i just created a new file with two copies of the bios after each other (256k + 256k = 512k) using this command.
cat cromwell256.bin cromwell256.bin > cromwell512.bin
Then just flash using the HTTP flash bios