The member entries are in PDS directory entry format.
PDS2NAME DS CL8
PDS2TTRP DS CL3
PDS2INDC DS B
PDS2INDC may be followed by user data. Discard the three high order bits in PDS2INDC. Multiply the vale of the 5 low order bits in PDS2INDC by 2 to determine the number of bytes of user data. Add 12 to determine the length of the directory entry.
The data is is in a modified track image. A single directory record has an 8 byte "key" followed by 2 bytes that define the used bytes in the 256 data block followed directory entries. The key is ABPRT. The data length is 00F8 followed by the first member at offset 02A1. Obviously the member name is $DYNPGM. PDS2TTRP is 000120 and PDS2INDC is 2C. The user data length is C, C*2=18 so the length of the directory entry is c+18=24 and the next directory entry is at 2C5, You step along through the block until you have processed all the directory entries in the block. The key for the next block is at 03AD and it is processed the same way.
0280 640 00000000 00000000 00FF8000 00000000 *................*
0290 656 00000000 080100C1 C2D7D9E3 40404000 *.......ABPRT .*
02A0 672 F85BC4E8 D5D7C7D4 40000120 2C000125 *8$DYNPGM .......*
02B0 688 00000000 00C3F300 02E802E8 00000088 *.....C3..Y.Y...h*
02C0 704 12000100 005BD7C7 D4C3C1D3 D3000120 *.....$PGMCALL...*
02D0 720 B1000125 00000000 00C3D300 02E802E8 *.........CL..Y.Y*
02E0 736 00014888 1A000000 005BC4E8 D5D7C7D4 *...h.....$DYNPGM*
02F0 752 4001005B D7C7D4C4 C5D34000 0120B100 * ..$PGMDEL .....*
0300 768 01250000 000000C3 D30002E8 02E80000 *.......CL..Y.Y..*
0310 784 C8881A00 0000005B C4E8D5D7 C7D44001 *Hh.....$DYNPGM .*
0320 800 005BD7C7 D4D3D6C1 C4000120 B1000125 *.$PGMLOAD.......*
0330 816 00000000 00C3D300 02E802E8 00002888 *.....CL..Y.Y...h*
0340 832 1A000000 005BC4E8 D5D7C7D4 400100C1 *.....$DYNPGM ..A*
0350 848 C2C5D5C4 F0C3F300 31152C00 311A0000 *BEND0C3.........*
0360 864 00000003 F2000010 00100000 00880000 *....2........h..*
0370 880 010000C1 C2D7D9E3 40404000 311C2C00 *...ABPRT .....*
0380 896 31210000 00000002 FF00E200 00800080 *..........S.....*
0390 912 00000088 00010100 00000000 00000000 *...h............*
03A0 928 00000000 00000000 00000801 00C1E2E3 *.............AST*
03B0 944 C1E3E240 4000FEC1 C4C4C1D3 C9C1E200 *ATS ..ADDALIAS.*
03C0 960 01272C00 012C0000 000000C2 E3001000 *...........BT...*
03D0 976 10000000 00880001 010000C1 D3D3D6C3 *.....h.....ALLOC*
03E0 992 E5D6D300 3C282C00 3C2D0000 000000C2 *VOL............B*
03F0 1008 E3000890 08900000 00880201 010000C1 *T........h.....A*
0400 1024 D3E3C4C9 D9404000 460B2C00 46100000 *LTDIR .........*
0410 1040 00000002 E2001578 15780000 00880001 *....S........h..*
0420 1056 010000C1 D5C1D3E3 E2E24000 012F2C00 *...ANALTSS .....*
0430 1072 02030000 00000002 E2002B68 29700000 *........S.......*
0440 1088 00880001 010000C1 D7C3C3C8 D2404000 *.h.....APCCHK .*
0450 1104 02082C00 020E0000 00000002 E2002F30 *............S...*
0460 1120 2F300000 00880201 010000C1 E2D4E3D6 *.....h.....ASMTO*
0470 1136 E9C1D700 02112C00 02160000 00000002 *ZAP.............*
0480 1152 E2001000 100000FF 00000088 00010100 *S..........h....*
0490 1168 00C1E2E3 C1E3E240 40003F0F 2C003F14 *.ASTATS .......*
04A0 1184 00000000 0002E200 1C001C00 00000088 *......S........h*
04B0 1200 00010100 00000000 00000000 00000000 *................*
04C0 1216 080100C2 D9D6D3C4 40404000 EEC2C3E2 *...BROLD ..BCS*
I'm not sure how you step from block to block in this data, and I'm not going to do any more research.
Good luck.
my bad 