vmu read and write

[kof888]

I mean ordinary, basic. Recently, in the game conversion of atomiswave, we found that although the archive is very large, we can simply compress it with DC's SH4 CPU before storing it in VMU. After compression, we can reduce the space by about 70%, so that we don't need too much space to archive it in VMU. But I'm not familiar with VMU. I haven't touched it before, so I'm not familiar with reading and writing VMU archives. So I want to ask if there are any materials and examples for reference.