| Author | OS Name | OS Version | Version of UtilityModule | Date of UtilityModule | OS Identifier | Part Number (OS_ReadSysInfo 9,1) | ROM Part Number | Remark |
| Acorn | Arthur | 0.20 | ?.?? | 06 Jun 1987 | ??? | - | ? | - |
| Acorn | Arthur | 0.30 | 0.30 | 17 Jun 1987 | &A0 | - | 0276,322-01 0276,323-01 0276,324-01 0276,325-01 | - |
| Acorn | Arthur | 1.10 | - | - | - | - | - | A300 service manual ROM fitting instructions: "The ROM set Numbered 1, 2, 3 and 4 although labelled Arthur 1.1 is in fact Arthur 1.2" |
| Acorn | Arthur | 1.20 | 1.20 | 25 Sep 1987 | &A0 | - | 0277,022-02 0277,023-03 0277,024-02 0277,025-02 | - |
| Acorn | RISC OS | 2.00 | 2.00 | 05 Oct 1988 | &A1 | - | 0283,022-01 0283,023-01 0283,024-01 0283,025-01 | - |
| Acorn | RISC OS | 2.00 | 2.00 | 12 Oct 1988 | &A1 | - | ? | used with the A500 |
| Acorn | RISC OS | 2.01 | 2.01 | 05 Jul 1990 | &A2 | - | 0270,601-01 0270,602-01 0270,603-01 0270,604-01 | used with A540 and R260 |
| Acorn | RISC OS | 2.50 | 2.50 | ?? ??? ???? | ??? | - | ? | mentioned in Acorn documentation |
| Acorn | RISC OS | 3.00 | 3.00 | 25 Sep 1991 | &A3 | - | 0270,251-01 0270,252-01 0270,253-01 0270,254-01 | used with early A5000 |
| Acorn | RISC OS | 3.10 | 3.10 | 30 Apr 1992 | &A4 | - | 0296,041-01 0296,042-01 0296,043-01 0296,044-01 | - |
| Acorn | RISC OS | 3.11 | 3.11 | 29 Sep 1992 | &A4 | - | 4 ROM set: 0296,041-02 0296,042-02 0296,043-02 0296,044-02 2 ROM set: 0296,061-01 0296,062-01 | - |
| Acorn | RISC OS | 3.12 | ?.?? | 09 Mar 1993 | ??? | - | (soft-loaded?) | German |
| Acorn | RISC OS | 3.19 | 3.19 | 09 Jun 1993 | &A4 | - | ? | German variant of RISC OS 3.11 |
| Acorn | RISC OS | 3.21 | ?.?? | ?? ??? ???? | ??? | - | (soft-loaded?) | for developers |
| ? | RISC OS | 3.50 | 3.50 | 18 Feb 1994 | &A5 | - | 0277,521-01 0277,522-01 | - |
| ? | RISC OS | 3.60 | 3.60 | ?? ??? ???? | ??? | - | (soft-loaded) | - |
| ? | RISC OS | 3.60 | 3.60 | 13 Apr 1995 | &A6 | - | 1203,101-01 1203,102-01 | - |
| ? | RISC OS | 3.70 | 3.70 | 24 Jul 1996 | &A7 | - | (soft-loaded) | - |
| ? | RISC OS | 3.70 | 3.70 | 30 Jul 1996 | &A7 | - | 1203,191-01 1203,192-01 | - |
| ? | RISC OS | 3.71 | 3.71 | 19 Feb 1997 | &A7 | - | 1203,261-01 1203,262-01 | - |
| ? | RISC OS | 3.80 | 3.80 | 28 Apr 1998 | &A8 | - | (soft-loaded) | - |
| RISCOS Ltd | RISC OS | 4.00 | 4.00 | 07 May 1999 | &A8 | 19990630-002 | ? | on Flash-ROM |
| RISCOS Ltd | RISC OS | 4.01 | 4.01 | ?? ??? ???? | &A8 | 19990713-002 | ? | - |
| RISCOS Ltd | RISC OS | 4.02 | 4.02 | 10 Aug 1999 | &A8 | 19990818-001 | ? | - |
| RISCOS Ltd | RISC OS | 4.03 | 4.03 | 09 Nov 1999 | &A8 | 19991214-001 | ? | used with RiscStation |
| RISCOS Ltd | RISC OS | 4.03 | 4.03 | 09 Nov 1999 | &A8 | 20000202-002 | ? | used with RiscStation |
| RISCOS Ltd | RISC OS | 4.03 | 4.03 | 09 Nov 1999 | &A8 | 20000330-002 | ? | used with Mico |
| RISCOS Ltd | RISC OS | 4.03 | 4.03 | 09 Nov 1999 | &A8 | 20000507-001 | ? | part of Castle's Kinetic upgrade |
| RISCOS Ltd | RISC OS | 4.04 | 4.04 | 22 Jan 2001 | &A8 | 20010308-001 | ? | part of Castle's Kinetic upgrade |
| RISCOS Ltd | RISC OS | 4.10 | 4.10 | 13 Aug 1999 | &A9 | 20000425-iii-build | (soft-loaded) | RISC OS Select |
| RISCOS Ltd | RISC OS | 4.11 | 4.11 | 26 Apr 2000 | &A9 | 20000502-iii-build | (soft-loaded) | RISC OS Select |
| RISCOS Ltd | RISC OS | 4.20 | 4.20 | 24 Jun 2001 | &A9 | 20010701-001 | (soft-loaded) | RISC OS Select |
| RISCOS Ltd | RISC OS | 4.28 | ?.?? | ?? ??? ???? | ??? | ? | (soft-loaded) | RISC OS Select |
| RISCOS Ltd | RISC OS | 4.29 | 4.29 | 23 Apr 2002 | &A9 | 20020428-001 | (soft-loaded) | RISC OS Select |
| RISCOS Ltd | RISC OS | 4.32 | 4.32 | ?? ??? ???? | &A9 | ? | (soft-loaded) | RISC OS Select |
| RISCOS Ltd | RISC OS | 4.33 | 4.33 | 30 Oct 2002 | &A9 | 20021118-001 | (soft-loaded) | RISC OS Select 2 Issue 3 |
| RISCOS Ltd | RISC OS | 4.37 | 4.37 | 11 Aug 2003 | &A9 | 20030915-001 | (soft-loaded) | RISC OS Select 3 Issue 3 |
| ? | NCOS | 1.06 | 4.50 | 26 Oct 1996 (OS Version Module: 08 Nov 1996) | ??? | - | 2203,021-01 2203,022-01 | used with Network Computer |
| ? | NCOS | 1.11 | 4.50 | 26 Oct 1996 (OS Version Module: 24 Feb 1998) | ??? | - | 2203,222-01 2203,223-01 | used with Network Computer |
| ? | NCOS | 1.15 | 4.59 | 15 May 1997 | ??? | - | ? | used with Network Computer |
| ? | RISC OS | 5.00 | ???? | ?? ??? ???? | ??? | ? | (Flash ROM) | 32 bit, used with Castle's Iyonix |
| ? | RISC OS | 5.01 | ???? | ?? ??? ???? | ??? | ? | (Flash ROM) | 32 bit, used with Castle's Iyonix |
| ? | RISC OS | 5.02 | ???? | ?? ??? ???? | ??? | ? | (Flash ROM) | 32 bit, used with Castle's Iyonix |
| ? | RISC OS | 5.05 | 5.05 | 17 Feb 2004 | &AA | ? | (Flash ROM) | 32 bit, used with Castle's Iyonix |
| ? | RISC OS-NC | 5.13 | 5.13 | 26 Jan 2000 (OS Version Module: 19 Oct 1999) | &A7 | - | 2208,670 2208,671 | used with Bush Internet Surf Set IBX-100 |
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