:10 0000 00 126A A5EF 00F0 ABB2 AB98 AB88 0C50 006E 53
10 = record type
0000 = start address
00 = number of bytes in record, 00=16??? Not 100% sure on this
126A = data, look below at your 2nd chunk of data sent...look familiar?

0000- 6a12 efa5 f000 b2ab 98ab 88ab 500c 6e00


The 1st file you sent is an actual INTEL HEX file, which is a different format than...
The 2nd file chunk you sent...which is actual data.

Google 'INTEL HEX record', you should find all the info you need somewhere out there...