$ xxd 1and2.dat
00000000: 4172 6368 6976 6546 696c 6502 0000 0001  ArchiveFile.....
00000010: 2e00 0000 789c 5362 8000 5620 3664 d063  ....x.Sb..V 6d.c
00000020: 2861 a800 6246 208f 1388 0581 3801 8895  (a..bF .....8...
00000030: 9054 19a1 a8e2 0362 3120 2e04 6200 b554  .T.....b1 ..b..T
00000040: 04df 0000 0000 0000 0000 0000 0000 0000  ................
00000050: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000060: 789c 2bce cf4d 5548 492c 4904 0011 8103  x.+..MUHI,I.....
00000070: 6f78 9c2b cecf 4d55 c8cd 2f4a 5548 492c  ox.+..MU../JUHI,
00000080: 4904 0028 1305 42                        I..(..B

(
Result of using the ph3 archiver on two files:

1.txt, with contents:
some data

2.txt, with contents:
some more data

Especially confounding is the large run of zero bytes.
)