; ==================================================
; Orion-128 computer
;
; ORDOS (Orion-DOS) System calls
; Disassembled by Romychs @ 2026-10-08
; ==================================================

; ORDOS Write max disk size
ORD_WMAX    EQU 0xbfc4

; ORDOS Read file attributes
; Out: HL -> file address in memory,
;      DE - file size,
;      BC -> directory address after search
ORD_ATFM    EQU 0xbfc7

; ORDOS Write start/end address of file buffer in RAM
;  Inp: HL = start addr
;       DE = end address
ORD_WATF    EQU 0xbfca

; ORDOS Read address of file buffer in RAM
ORD_ATF     EQU 0xbfcd

; ORDOS Set address of filename buffer
;  Inp: HL -> filename
ORD_SDNA    EQU 0xbfd0

; ORDOS Read address of filename buffer
ORD_LDMA    EQU 0xbfd3

; ORDOS Set current drive
;  Inp: A - 'A' or 'B' drive letter
ORD_WND     EQU 0xbfd6


; ORDOS Read byte from disk
;  Inp: HL -address.
;  Out: A - byte from disk
ORD_RDISK   EQU 0xbfdc

; ORDOS Write byte to disk
;  Inp: HL -address,
;       A - byte to write
ORD_WDISK   EQU 0xbfdf

ORD_STOP    EQU 0xbfe2

; ORDOS Search file on disk
;  Inp: Filename will be set before call
;  Out: A = 0 - not found, 0xff - found
;       HL -> stop byte if not found, of file header if found
ORD_PSCF    EQU 0xbfe5

; ORDOS Read current disk name
ORD_RND     EQU 0xbfe9

; ORDOS Erase disk file
; Out: A = 0 - ok
;      A = 1 - no file found
;      A = 4 - read only
ORD_ERAS    EQU 0xbfee

; ORDOS Open sequential file for read
ORD_OFILL   EQU 0xbff1

; ORDOS Close sequential file
ODR_CFILL   EQU 0xbff4

; ORDOS Write file on disk
; Out: A = 0 - success
;      A = 2 - repeat
;      A = 3 - no space left
ORD_WFILE   EQU 0xbff7

; ORDOS Read file from disk
;  Out: A = 0 - ok, 1 - file not found, 0x80 - COM file
;       HL -> start address of buffer
;       SP+2 -> return to OS address
ORD_RFILE   EQU 0xbffa

; ORDOS Start. Entry point to ORDOS (JP)
ORD_START   EQU 0xBFFD

; Start sddress of ORDOS
ORD_STADR   EQU 0xBFFE