All your seganet dump are baddumped and most of them have already been dumped correctly.

F:\&gt;md_headerchk.exe -h "16 Ton (SN) (GNKO) (J) (hidden-palace.org) [!].bin"
Title            : SEGA MEGA DRIVE
Copyright        : (C)SEGA 1989.OCT
Domestic Name    : SEGANET GAME
Oversea Name     : SEGANET GAME
Product Code     : GM 00054503-00
Int Checksum     : a9e9
Calc Checksum    : 36aa
Checksum         : BAD
I/O              : JDR
ROM Start        : 0x00000000
ROM End          : 0x0001ffff
ROM Size         : 131071 (file size : 262143)
RAM Start        : 0x00ff0000
RAM End          : 0x00ffffff
Backup RAM Start : 0x00200001
Backup RAM End   : 0x00200001
Modem DATA       : MOSEGA03.000
Note             :
Region           : J

F:\&gt;md_headerchk.exe -h "Sega Megadrive Genesis 32X (20060814)\[SegaNet] 16t (J).md"
Title            : SEGA MEGA DRIVE
Copyright        : (C)SEGA 1989.OCT
Domestic Name    : SEGANET GAME
Oversea Name     : SEGANET GAME
Product Code     : GM 00054503-00
Int Checksum     : 36aa
Calc Checksum    : 36aa
Checksum         : OK
I/O              : JDR
ROM Start        : 0x00000000
ROM End          : 0x0003ffff
ROM Size         : 262143 (file size : 262143)
RAM Start        : 0x00ff0000
RAM End          : 0x00ffffff
Backup RAM Start : 0x00200001
Backup RAM End   : 0x00200001
Modem DATA       : MOSEGA03.000
Note             :
Region          : J