Extract double in binary file

[Pascal]

Hello,

I've a binary file with data in it.
This file come from an old ms dos application (multilog ~ 1980).
In this application, a field is declared as a 'decimal' (999 999
999.99).
I put 0.00 in the field and save the record to the file.
When I look in the binary file (with python or an hex editor), the
field is stored on 8 bytes: 00-00-00-00-00-00-7F-00.
I try unpack from struct module but the result isn't good.

Can someone help me?

Thanks.