This page describes the format of an Intel hex file produced by a suitable assembler. This code is often downloaded from a PC to a development system and run from RAM. Alternatively, the hex file can be converted to a binary file and programmed into an EPROM.

Here is an example hex file:

:10008000AF5F67F0602703E0322CFA92007780C361
:1000900089001C6B7EA7CA9200FE10D2AA00477D81
:0B00A00080FA92006F3600C3A00076CB
:00000001FF

Now look at the top line...

• The first character (:) indicates the start of a record.
• The next two characters indicate the record length (10h in this case).
• The next four characters give the load address (0080h in this case).
• The next two characters indicate the record type (see below).
• Then we have the actual data.
• The last two characters are a checksum (sum of all bytes + checksum = 00).

Record types:

• 00 - Data record
• 01 - End of file record
• 02 - Extended segment address record
• 03 - Start segment address record
• 04 - Extended linear address record
• 05 - Start linear address record