De AXR1 is een EPROM die ontwikkeld is door de Stichting Electronica Workshop (ECD/SEW), Delft in 1981 tot 1983 en voorziet de Atom van negentien extra commando's. Ook bekend als Josbox. Omdat het geen standaard Acorn Atom ROM is zijn de extra commando's in het kort beschreven:

Command       Abbr.          Description
------- ----- -------------------------------------------------------
DATA DA. A sequential one line file marker
Syntax: [<ARGUMENT0> ... <ARGUMENTn>]
RESTORE RES. Resets the file pointer to a specified DATA line 
Syntax: [<LINENUMBER>|<EXPRESSION>|<LABEL>]
READ REA. Get records from a DATA line 
Syntax: <VARIABLE0>[,<VARIABLE1> ... <VARIABLEn>]
FIND Locates specified strings in a BASIC program
Syntax: <LITTERAL STRING>|<STRING VARIABLE>
RENUM REN. Renumbers a BASIC program and adjusts GOTO's etc.
Syntax: [<START LINE>,<INCREMENT>]
FCOS FC. Fast 1200 bps COS with visible tape transfer indication
SCOS SC. Same as FCOS, but with 300 bps
XDUMP X. Gives ASCII/hexadecimal memory dumps
Syntax: <START ADDRESS>[,<END ADDRESS>]
HDUMP H. Gives hexadecimal memory dumps
Syntax: <START ADDRESS>[,<END ADDRESS>]
DISAS DI. A fast 6502 machine code disassembler
Syntax: <START ADDRESS>[,<END ADDRESS>]
COPY COP. Copies memory blocks to a specified destination
Syntax: <START ADDRESS>,<END ADDRESS>,<DESTINATION ADDRESS>
RELOC REL. Relocates 6502 machine code to a specified destination
Syntax: <START ADDRESS>,<END ADDRESS>,<DESTINATION ADDRESS>
STEP STE. A versatile 6502 machine code debugger
Syntax: <START ADDRESS>[,<DISPLAY ADDRESS>]
PLAY PL. Provides a versatile method of sound output
Syntax: <NOTE0>[,<NOTE1> ... <NOTEn>]
KEY K. Performs a single keyboard scan
Syntax: <VARIABLE>
ON ERR O. Redefines error handling
Syntax: <BASIC STATEMENT>
SHAPE SHA. Draws anything you want on the screen in any mode
GRMOD GR. Allows HIRES graphics to be mixed with normal characters
TXMOD T. Disables GRMOD and returns control to the 6847