Acorn NFS 3.40 Memory Map

← Acorn NFS and Acorn ANFS

Addresses outside the ROM used by Acorn NFS 3.40 at run time — zero-page workspace, RAM buffers, and memory-mapped I/O. For the ROM code itself (&8000&9FFF), see the disassembly listing.

Index bases

Addresses used only as an indexing base — the operand names a base and the byte actually touched is base + X (or + Y), where the index register is a caller-supplied offset, never zero. The literal byte at the base address is never read or written, so these are documented here rather than on the memory map: they are bases, not locations the ROM owns.

Other

Base Name Description
&0002 zp_work_2
&0003 zp_work_3
&00AE work_ae
&00AF addr_work
&00C2 txcb_dest
&00C7 txcb_pos
&0D1A nmi_shim_1a
&0D26 tx_data_start
&0D41 rx_remote_addr
&0DE6 nmi_sub_table
&0DEB fs_state_deb
&0DF0 rom_ws_table
&0DFE fs_context_base
&0E30 fs_filename_buf
&0EF7 fs_reply_data
&0F0D fs_file_len
&0FE0 fs_error_buf