OK i think i have this 99% figured out.
as an example to others using my Sanyo VCR
i did the learn a code routine for the power button and assigned it to button A
https://www.hifi-remote.com/forums/viewtopic.php?t=3943
I then downloaded from this remote using IR.exe and it had learnt
VCR:A
entry 1
Protocol = Nec1
Device = 49
subdevice (nothing given)
OBC =91
Hex CMD = 25
EFC = 235
going to this page since i know that 0104 is the device
http://www.hifi-remote.com/cgi-bin2/ueic.cgi?VCR_0104
when i look for the word power i find 235 = Power.
I know I won't find such a useful page for every device but when you do it helps
http://controlremote.sourceforge.net/rmhelp/rmhelp.html
explains things but i didn't really understand it at first.
switching to RM i can now start to develop my upgrade
i select a remote corresponding to the remote i want an upgrade for
using convention (add 1000 to the existing code) i should make my setup code 1104
i select NEC1 as my protocol (from Ir)
and device type is VCR (its a sanyo vcr)
on the functions tab i find a line for power and enter 235 in the EFC Column soon as i tab from there the other 2 numbers get filled in.
the slow way to fill in the rest of the table and any functions is to learn them from my existing remote or if i want to guess
http://www.hifi-remote.com/ofa/advanced.shtml
(basically press setup and enter in 3 digit codes from 000 to 256 and see what happens)
lucky me i don't have to guess codes or learn codes because
http://www.hifi-remote.com/cgi-bin2/ueic.cgi?VCR_0104
gives me a list of codes for 0104 and a useful name for each code
the numbers are EFC numbers which are the same numbers you guess at
when you enter a 3 digit code.
OK assuming i have entered all my codes the next stage is to map my functions to my remote. some can be done automatically the rest is up to me to find a suitable button.
the layout page has a pic of my remote and i can drag and drop the functions on to the remote.
the output tab has a thing called device upgrade code i copy everything in that panel and
switch to Ir
choose the device panel select add and paste the device upgrade code into the top panel of the window that appears (keyshifts are automatically put in the bottom panel).
i then should have a new entry for 1104 and if i select upload to the remote my upgrade is installed and my new codes will be in place when i press VCR button (provided my VCR button on the general page has 1104 as device code on the VCR.)
thinking a little about this it might be possible to make a macro to switch a device key from one device to another. thus allowing more devices to be controlled by the same remote ... maybe.
I do have one question left thou
when you go to the device tab of IR and click add in the "Upgrade device" window the middle pane has the heading device and a tick box with protocol >FF
I understand that most of the settings within device are set automatically when you paste in your codes from RM but the protocol tick box is that automatic too?
Thank you to capn trips and mark pierson for posting in this thread and helping me to an understanding of how this all works
and of course thank you to rob for hosting such a fine and useful site.
the key concept you need to understand its basically a 1 direction process
you go from generating or loading an upgrade in RM to pass to IR to be uploaded. The only easily understood thing you can get from IR apart from a backup prior to playing is the learned function tab since this gives the protocol and an EFC number for a particular known function.
I don't see a way to go backwards through IR since probably your using a device code in ROM which you can't read directly through JP1.