.include "rom_layout.inc"

; Stable assembly ABI exported by the resident BIOS.
BIOS_PUTC        = RESIDENT_RAM_BASE + 0x50 ; A = character; preserves all registers
BIOS_TRY_GETC    = RESIDENT_RAM_BASE + 0x53 ; returns A = character or 0; preserves BC..IY
BIOS_GETC        = RESIDENT_RAM_BASE + 0x56 ; blocking; returns character in A
BIOS_IO_OUT      = RESIDENT_RAM_BASE + 0x59 ; A = port, L = value; preserves all registers
BIOS_IO_IN       = RESIDENT_RAM_BASE + 0x5C ; A = port; returns value in A
BIOS_DELAY_MS    = RESIDENT_RAM_BASE + 0x5F ; HL = milliseconds; preserves all registers
BIOS_MONITOR     = RESIDENT_RAM_BASE + 0x62 ; warm-start the monitor; does not return
BIOS_BANK        = RESIDENT_RAM_BASE + 0x65 ; A=0 split 48K/16K, otherwise upper 64K
BIOS_ROM_DISABLE = RESIDENT_RAM_BASE + 0x68 ; disable ROM while preserving the bank selection
BIOS_ROM_ENABLE  = RESIDENT_RAM_BASE + 0x6B ; enable ROM while preserving the bank selection