diff --git a/asminc/cpu.mac b/asminc/cpu.mac
index a006a9882..15b16bad5 100644
--- a/asminc/cpu.mac
+++ b/asminc/cpu.mac
@@ -5,15 +5,15 @@ CPU_ISET_6502      = $0002
 CPU_ISET_6502X     = $0004
 CPU_ISET_6502DTV   = $0008
 CPU_ISET_65SC02    = $0010
-CPU_ISET_65C02     = $0020
+CPU_ISET_65C02     = $0020  ; Rockwell extensions
 CPU_ISET_65816     = $0040
 CPU_ISET_SWEET16   = $0080
 CPU_ISET_HUC6280   = $0100
 CPU_ISET_M740      = $0200
 CPU_ISET_4510      = $0400
 CPU_ISET_45GS02    = $0800
-CPU_ISET_W65C02    = $1000
-CPU_ISET_65CE02    = $2000
+CPU_ISET_W65C02    = $1000  ; WDC extensions
+CPU_ISET_65CE02    = $2000  ; CSG extensions
 
 ; CPU capabilities
 ; make sure to only combine the instruction sets that are 100% compatible
@@ -28,9 +28,7 @@ CPU_W65C02         = CPU_ISET_W65C02  | CPU_ISET_6502 | CPU_ISET_65SC02 | CPU_IS
 ; FIXME: CPU_ISET_65SC02 does not apply to the following, because the zp-indirect
 ; addressing was replaced with zp-indirect,z-indexed in 652SCE02
 
-; NOTE: HUC6280 removes "wai" ($cb) and "stp" ($db) from the 65C02 instruction set
 CPU_HUC6280        = CPU_ISET_HUC6280 | CPU_ISET_6502 | CPU_ISET_65C02
-; NOTE: 4510 replaces "wai" ($cb) and "stp" ($db) of the 65C02 instruction set
 CPU_4510           = CPU_ISET_4510    | CPU_ISET_6502 |                   CPU_ISET_65C02 | CPU_ISET_65CE02
 CPU_45GS02         = CPU_ISET_45GS02  | CPU_ISET_6502 |                   CPU_ISET_65C02 | CPU_ISET_65CE02 | CPU_ISET_4510
 CPU_M740           = CPU_ISET_M740    | CPU_ISET_6502