Just in case, someone is interested... Feel free to redistribute the information, if you like to.
List of MSX tR default CALL commands sorted by slots (Made By: NYYRIKKI 2005)
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#0-2 (MSX-Music)
-------------------
AUDREG
APPEND MK *
APEEK *
APOKE *
BGM
CONT MK *
COPY PCM *
CONVP *
CONVA *
INMK *
KEY ON *
KEY OFF *
LOAD PCM *
MDR
MK VOICE *
MK VEL *
MK VOL *
MK TEMPO *
MK STAT *
MK PCM *
MUSIC
REC PCM *
STOPM
SET PCM *
SAVE PCM *
SYNTHE *
TRANSPOSE
TEMPER
VOICE
VOICE COPY
PAUSE
PLAY
PLAY PCM *
PCM PLAY
PCM REC
PCM FREQ *
PCM VOL *
PLAY MK *
PITCH
* Detected, but not supported (causes illegal function call)
#3-1 (Kanji ROM)
------------------------
PALETTE
CLS
AKCNV
JIS
SJIS
KACNV
KEXT
KINSTR
KLEN
KMID
KNJ
KTYPE
KANJI
KANJI0
KANJI1
KANJI2
KANJI3
ANK
#3-2 (Disk ROM)
------------------------
SYSTEM
FORMAT
CHDRV *
CHDIR *
MKDIR *
RMDIR *
RAMDISK *
* Only when DOS2 is active.
#3-3 (Panasonic Mapper)
------------------------
MWP *
HIRO **
* Only in Panasonic FS-A1GT
** Only in Panasonic FS-A1ST
(CALL MENU in Panasonic 2+ machines)