It worked by appending zeroes to the file: $ dd if=/dev/zero of=zeroes bs=1 count=$((16384-2048)) $ cat CIP-01\ \(19xx\)\(Intreprindera\ Electronica\).rom zeroes > CIP.rom
I have the following two roms: $ ls -l total 48 -rw-r--r--. 1 x x 2048 Sep 29 2023 'CIP-01 (19xx)(Intreprindera Electronica).rom' -rw-r--r--. 1 x x 16384 Sep 29 2023 'CIP-03 (19xx)(Intreprindera Electronica).rom' I can use the 16384 bytes rom just fine, but not the 2048 one: $ fuse --rom-48 CIP-03\ \(19xx\)\(Intreprindera\ Electronica\).rom $ fuse --rom-48 CIP-01\ \(19xx\)\(Intreprindera\ Electronica\).rom [...] fuse: error: ROM 'CIP-01 (19xx)(Intreprindera Electronica).rom' is 2048 bytes long; expected...