Nascom
ROM
BASIC
Dis–Assembled

Part 2

By Carl Lloyd–Parker

Dis-assembly of NASCOM ROM BASIC Ver 4.7                PAGE    1

                ; GENERAL EQUATES

0001            UARTD   EQU     01H             ; UART data port
0002            UARTS   EQU     02H             ; UART status port
0003            CTRLC   EQU     03H             ; Control "C"
0007            CTRLG   EQU     07H             ; Control "G"
0008            BKSP    EQU     08H             ; Back space
000A            LF      EQU     0AH             ; Line feed
000C            CS      EQU     0CH             ; Clear screen
000D            CR      EQU     0DH             ; Carriage return
000F            CTRLO   EQU     0FH             ; Control "O"
0012            CTRLR   EQU     12H             ; Control "R"
0013            CTRLS   EQU     13H             ; Control "S"
0015            CTRLU   EQU     15H             ; Control "U"
001A            CTRLZ   EQU     1AH             ; Control "Z"
001B            ESC     EQU     1BH             ; Escape
001C            TBRK    EQU     1CH             ; "T" monitor break
001D            TBS     EQU     1DH             ; "T" monitor back space
001E            TCS     EQU     1EH             ; "T" monitor clear screen
001F            TCR     EQU     1FH             ; "T" monitor carriage return
007F            DEL     EQU     7FH             ; Delete

                ; MONITOR LOCATIONS

0000            MONSTT  EQU     0000H           ; Start of monitor
000D            STMON   EQU     000DH           ; NAS-SYS initialisation
0051            MFLP    EQU     0051H           ; Flip tape LED ("T")
008D            MONTYP  EQU     008DH           ; Type of "T" monitor
03D1            T2DUMP  EQU     03D1H           ; "T2" Dump routine
0400            T4WR    EQU     0400H           ; "T4" Write routine
070C            T4READ  EQU     070CH           ; "T4" Read routine
0800            VDU     EQU     0800H           ; Nascom Video RAM base

                ; MONITOR WORK SPACE LOCATIONS

0C00            PORT0   EQU     0C00H           ; Copy of output port 0
0C0C            ARG1    EQU     0C0CH           ; Argument 1
0C0E            ARG2    EQU     0C0EH           ; Argument 2
0C18            TCUR    EQU     0C18H           ; "T" monitor cursor
0C29            CURSOR  EQU     0C29H           ; NAS-SYS Cursor
0C2B            ARGN    EQU     0C2BH           ; Number of ARGS
0C4A            TOUT    EQU     0C4AH           ; "T" Output reflection
0C4D            TIN     EQU     0C4DH           ; "T" Input reflection
0C75            CIN     EQU     0C75H           ; NAS-SYS Input table
0C7E            NMI     EQU     0C7EH           ; NAS-SYS NMI Jum