Copy everything between asterisks into notepad save as (all files) RC5x.irp. If you are using the older version the top irp file works. If you are using Version 4 the bottom. As you probably know MakeHex will only create commands in the learned format.
Note that:
System (in official documentation)=Device=D (MakeHex) D ranges from 0 to 31
Command=Sub-Device=S; S ranges from 0 to 127
Data=Function=F ranges from 0 to 63
In MakeHex Device is specified as Device.Sub-device
In order to translate the database command:
5001 0000 0000 0002 0010 000C 0001 0000
The last four double byte words (four digits) are in decimal 16, 12, and 1 (0000 is ignored)
For that Device=16.12
Function=1
However Marantz publishes ccf files for their version of the Pronto and these have a very large library of Marantz equipment. If you are using a Pronto that supports the database format, you really want to express them in that format (starts with 5001 to work correctly -- toggle bit and all that):
[Link: marantz.com]'*******************OriginalVersion*******************
Device=16.12
Function=0..63
Protocol=RC5x
Frequency=36000
Time Base=889 '888.89 = 32 cycles at 36Khz
Message Time=113778 '128 times TimeBase of 888.89
Zero=1,-1
One=-1,1
First Bit=MSB
Form=;1:1,~C:1,T:1,D:5,*,E:6,F:6
R-Prefix=0,-4
Define=C as S(6..6)
Define=E as S(0..5)
'****************************************************
'************************NEW VERSION 4.1************
Device=16.12
Function=0..63
Protocol=RC5x
Frequency=36000
Time Base=889 '888.89 = 32 cycles at 36Khz
Message Time=128
Zero=1,-1
One=-1,1
First Bit=MSB
Form=;1:1,~S:1:6,T:1,D:5,*,S:6,F:6
R-Prefix=0,-4
Define T=0
'***********************************************