The project contains the following IBM PC BASIC ROMs:

These built-in versions of BASIC were also referred to as Cassette BASIC, because no disk drive was required. Only the original IBM PC (Model 5150) actually provided a cassette interface, but IBM continued to use that name to describe the built-in BASIC, at least up through the IBM PC AT (Model 5170).

Both versions of Cassette BASIC were 32Kb and spanned physical addresses 0xF6000-0xFDFFF. They were produced by Microsoft, and unlike the IBM PC BIOS ROMs, no source code listings of these BASIC ROMs were ever published.

Here’s an IBM PC Machine XML excerpt that shows how to include a BASIC ROM:

<rom id="romBASIC" addr="0xf6000" size="0x8000" file="/devices/pcx86/rom/5150/basic/BASIC100.json"/>