In order not to forget things like RNG addresses (which I forget easily since I apparently did not document this on a fixed page anywhere), I have created a very basic Lua script that monitors RNG in any Mega Man game that uses "MMX RNG", including MMX-X6, MM7 and R&F. You can download the script here:
https://tasvideos.org/UserFiles/Info/638585240848962683 .
Although this script does not display everything related to Rush Search, it should be useful for getting the RNG value to line up, especially the "R-2F" value displayed there as well.
* I'll add a few other things about MM7 and how Rush Search works (at least so I don't forget in the future). The RNG address is at 0xFA. The RNG subroutine in ROM is at 0xC1023D.
There are two calls to RNG per frame which are not used (at ROM addresses 0xC00CD2 and 0xC10CB4). They occur before other RNG calls. When Rush Search is summoned, just before the tail wag animation, there is a call to the RNG at 0xC14B85:
c14b85: jsl $c1023d [c1023d] A:6280 X:0074 Y:0002 S:012e D:0c80 DB:80 NvMXdizc V:260 H:210
...
c14b89: and #$03 A:754e X:0074 Y:0002 S:012e D:0c80 DB:80 NvMXdizc V:260 H:305
c14b8b: clc A:7502 X:0074 Y:0002 S:012e D:0c80 DB:80 nvMXdizc V:260 H:308
c14b8c: adc #$03 A:7502 X:0074 Y:0002 S:012e D:0c80 DB:80 nvMXdizc V:260 H:311
c14b8e: sta $3a [000cba] A:7505 X:0074 Y:0002 S:012e D:0c80 DB:80 nvMXdizc V:260 H:314
c14b90: rts A:7505 X:0074 Y:0002 S:012e D:0c80 DB:80 nvMXdizc V:260 H:320
This call takes the RNG value mod 4, and adds 3 to it, to get the number of Rush tail wags (from 3 to 6).
Then after the tail wag animation has finished, the next frame gives two more RNG calls. One is for the item obtained:
c14d38: jsl $c1023d [c1023d] A:ffff X:0003 Y:001e S:012c D:0c80 DB:80 NvMXdizc V:254 H:152
...
c14d3c: cmp #$ff A:5d65 X:0003 Y:001e S:012c D:0c80 DB:80 NvMXdizc V:254 H:246
c14d3e: bne $4d41 [c14d41] A:5d65 X:0003 Y:001e S:012c D:0c80 DB:80 nvMXdizc V:254 H:249
c14d41: ldx #$00 A:5d65 X:0003 Y:001e S:012c D:0c80 DB:80 nvMXdizc V:254 H:254
c14d43: cmp $a3e2,x [80a3e2] A:5d65 X:0000 Y:001e S:012c D:0c80 DB:80 nvMXdiZc V:254 H:257
c14d46: bcc $4d4b [c14d4b] A:5d65 X:0000 Y:001e S:012c D:0c80 DB:80 nvMXdizC V:254 H:263
c14d48: inx A:5d65 X:0000 Y:001e S:012c D:0c80 DB:80 nvMXdizC V:254 H:266
c14d49: bra $4d43 [c14d43] A:5d65 X:0001 Y:001e S:012c D:0c80 DB:80 nvMXdizC V:254 H:269
c14d43: cmp $a3e2,x [80a3e3] A:5d65 X:0001 Y:001e S:012c D:0c80 DB:80 nvMXdizC V:254 H:273
c14d46: bcc $4d4b [c14d4b] A:5d65 X:0001 Y:001e S:012c D:0c80 DB:80 nvMXdizC V:254 H:279
c14d48: inx A:5d65 X:0001 Y:001e S:012c D:0c80 DB:80 nvMXdizC V:254 H:282
c14d49: bra $4d43 [c14d43] A:5d65 X:0002 Y:001e S:012c D:0c80 DB:80 nvMXdizC V:254 H:285
...
c14d43: cmp $a3e2,x [80a3e8] A:5d65 X:0006 Y:001e S:012c D:0c80 DB:80 nvMXdizC V:255 H: 15
c14d46: bcc $4d4b [c14d4b] A:5d65 X:0006 Y:001e S:012c D:0c80 DB:80 NvMXdizc V:255 H: 21
c14d4b: stx $3b [000cbb] A:5d65 X:0006 Y:001e S:012c D:0c80 DB:80 NvMXdizc V:255 H: 25
c14d4d: rts A:5d65 X:0006 Y:001e S:012c D:0c80 DB:80 NvMXdizc V:255 H: 32
c14ba4: ldx $3b [000cbb] A:5d65 X:0006 Y:001e S:012e D:0c80 DB:80 NvMXdizc V:255 H: 42
c14ba6: lda $a3fc,x [80a402] A:5d65 X:0006 Y:001e S:012e D:0c80 DB:80 nvMXdizc V:255 H: 48
c14ba9: and #$bf A:5d84 X:0006 Y:001e S:012e D:0c80 DB:80 NvMXdizc V:255 H: 56
c14bab: sta $3d [000cbd] A:5d84 X:0006 Y:001e S:012e D:0c80 DB:80 NvMXdizc V:255 H: 59
The above code compares (RNG value mod 256) by going through a table to determine the item. The following site gives the resulting probabilities:
https://www.thesupersnes.tv/compendium/mm7/rush-search/ . In particular, small life energy needs a value of 0x00 to 0x17, large life energy 0x18-0x1F, small weapon energy 0x20-0x37 and large weapon energy 0x38-0x3F.
Finally, the other RNG call is for how many times to repeat Rush's dig animation:
c14bba: jsl $c1023d [c1023d] A:6180 X:0074 Y:0002 S:012e D:0c80 DB:80 NvMXdizc V:255 H:299
...
c14bbe: and #$03 A:2f38 X:0074 Y:0002 S:012e D:0c80 DB:80 NvMXdizc V:256 H: 53
c14bc0: clc A:2f00 X:0074 Y:0002 S:012e D:0c80 DB:80 nvMXdiZc V:256 H: 56
c14bc1: adc $3d [000cbd] A:2f00 X:0074 Y:0002 S:012e D:0c80 DB:80 nvMXdiZc V:256 H: 59
c14bc3: and #$7f A:2f84 X:0074 Y:0002 S:012e D:0c80 DB:80 NvMXdizc V:256 H: 65
c14bc5: sta $3a [000cba] A:2f04 X:0074 Y:0002 S:012e D:0c80 DB:80 nvMXdizc V:256 H: 68
c14bc7: rts A:2f04 X:0074 Y:0002 S:012e D:0c80 DB:80 nvMXdizc V:256 H: 75
Take RNG value mod 4, and add it to a fixed number depending on the item obtained to get the number of loops in the dig animation. For small life and weapon energy, add 2 (from 2 to 5). For large life and weapon energy, add 8 (from 8 to 11).
Note on RAM addresses:
0xCBA = # of tail wags / digging loops,
0xCBB = X value of item obtained, from 0 to 25. (0 = small life energy, 1 = large life energy, 2 = small weapon energy, 3 = large weapon energy)
0xCBD = # of fixed dig loops to add to Rush's digging animation. If bit 7 is set, Rush does a second digging animation of 5 faster digs (only for certain items).