h6. [[Programmer's Reference Manuals]] h6(. » OS Codes h2. OS Codes table(bordered). |_<^{width:3em}. Value|_<^. Version| |<^. &A0 |<^. Arthur 1.20| |<^. &A1 |<^. RISC OS 2.00| |<^. &A2 |<^. RISC OS 2.01| |<^. &A3 |<^. RISC OS 3.00| |<^. &A4 |<^. RISC OS 3.10/3.11| |<^. &A5 |<^. RISC OS 3.50| |<^. &A6 |<^. RISC OS 3.60| |<^. &A7 |<^. RISC OS 3.70| |<^. &A8 |<^. RISC OS 3.80/4.0x| |<^. &A9 |<^. RISC OS 4 Select| |<^. &AA |<^. RISC OS 5.0x, 5.1x, 5.2x| |<^. &AE |<^. RISC OS Pyromaniac| h4. Notes The version of the Operating System is specified by the value returned in R1 when using [[OS_Byte 129 (OS)|OS_Byte 129 (read OS version)]]. h4. See also * [[OS_Byte 129]] * [[OS_Byte 129 (OS)|OS_Byte 129 (read OS version)]]