Romik-Microdeal T2
Found on:
"Mr. Dig"
Loader files:
ROM Header
Only filename
ROM Data
Turbo loader
Encoding:
Only filename
ROM Data
Turbo loader
Endianess:LSbF
Threshold:0x013E
Lead-in:7680 x 1-bit
Sync:None
Byte:12+ bits
0-bit:Short
Structure:Threshold:0x013E
Lead-in:7680 x 1-bit
Sync:None
Byte:12+ bits
0-bit:Short
Header:Yes
Checksum:Yes
Checksum:Yes
Lead-in:
Lead-in is 7680 1-bits, loader only checks for 256 consecutive 1-bits.
Byte:
For every byte the first two bits are ignored.
The the loader wait for the first 0-bit.
It then fetches the 8 bits making up the byte.
After these bits comes a parity bit which should be '1' for odd parity.
Data:
Data is ordered into 16+1 byte blocks.
Loader first waits for three consecutive 1-bits.
Then follows 16 data bytes and a checksum byte for the block.
Checksum:
Checksum is EOR of the 16 bytes in a block, with the checksum byte directly following the block.
The header is also followed by a checksum byte.
Loader doesn't verify the checksum, it is used to repair a byte if a parity error has been detected.
Header:
00 Load start address high byte
01 Load end address high byte (Exclusive)
02-03 Address to subroutine to call before game start (Low/high order)
04 ??
05-0F Filename
Lead-in is 7680 1-bits, loader only checks for 256 consecutive 1-bits.
Byte:
For every byte the first two bits are ignored.
The the loader wait for the first 0-bit.
It then fetches the 8 bits making up the byte.
After these bits comes a parity bit which should be '1' for odd parity.
Data:
Data is ordered into 16+1 byte blocks.
Loader first waits for three consecutive 1-bits.
Then follows 16 data bytes and a checksum byte for the block.
Checksum:
Checksum is EOR of the 16 bytes in a block, with the checksum byte directly following the block.
The header is also followed by a checksum byte.
Loader doesn't verify the checksum, it is used to repair a byte if a parity error has been detected.
Header:
00 Load start address high byte
01 Load end address high byte (Exclusive)
02-03 Address to subroutine to call before game start (Low/high order)
04 ??
05-0F Filename