These files generated by the PMARC2 utility for MSX-DOS.
This was done using openMSX emulating an MSX2 (Philips_NMS_8250).

Information on the PMARC tool can be found here:

    http://www.faq.msxnet.org/suffix.html

pm0.pma         - Archive with uncompressed file (/n option)
pm2.pma         - Archive with compressed -pm2- format file.
comment.pma     - Archive with a file that has a comment memorandum.
sfx.com         - Self-extracting PMA archive.

