Acorn BASIC Floating Point
Extension
"This is an additional 4K byte program which adds 9-digit
floating point manipulation to the repertoire of the integer BASIC interpreter.
Also included are scientific function and plot routines for the VDU.
There are two variants available for the System and Atom versions of BASIC. The main differences are in the additional graphic routines which are tailored to suit the different VDU hardware. I am in the process of producing a source code, in ca65 format, which by changing a 'switch' will assemble either the System or Atom variant. The System variant has graphic routines for the 40x25 VDU (Teletext), I haven't seen an 80x25 VDU variant ?
The Floating Point Extension
The Floating Point Extension is documented in
System
On a System 2 the Floating Point Extension will be in a ROM/EPROM whereas for disk based systems (System 3/4/5) it will be loaded from floppy into RAM.
Atom
On an Atom the Floating Point Extension will be in a ROM/EPROM in the IC21 socket.
There is an .ssd image containing System BASIC together with the Floating Point and ONLINE Extensions on the System BASIC page.