This ASCII format consists of a series of CR+LF terminated "records" of ASCII text. Each record has the following structure: a start-of-record character "S", an ASCII record type digit (0-9), a two-digit ASCII hex byte count, a four-digit ASCII hex address, an optional sequence of two-digit ASCII hex data values, and a two-digit ASCII hex checksum. The LW tool chain issues only S0, S1, S5 and S9 record types. S1 records are limited to maximum of 16 data bytes in length, and paragraph alignment of addresses is favored. The address sequence of the S-Records directly follows that of the source file; multiple ORG directives in the source code may result in out-of-sequence addresses in the S-Record output.
Motorola S-Record format is a standard ASCII format accepted by most memory device programming equipment. It is particularly useful when the assembled code output is destined to reside within an EPROM or Flash memory device, for example.
LWASM can output this format since version 4.10. LWLINK can output this format since version 4.11.