Posted by lakkdainen on February 08, 2002 at 23:29:17:
In Reply to: Re: IPac - can't program F7??? posted by Andy Warne on February 08, 2002 at 16:30:47:
For a while there I questioned my sanity. :) Glad to hear there is an acttual technical explanation.
Jon
: That is correct, this key is one of 4 which you cannot program. The others are print screen, pause
: and the numpad "/".
: The reason: They have weird scancodes in the IBM code set. The F7 key is the only one that uses bit 7 of the code in the entire set. This bit is used for a vital function in the I-PAC chip: it signifies a "key up" code in order to save RAM and give maximum speed. The other 3 are just completely crazy sequences of codes which must have been dreamt up by someone in IBM simply to confuse people! For example the scan code for pause is E1 14 77 E1 F0 14 77. go figure! To implement these would have required much extra processing overhead.
: The F7 key will need to be remapped in MAME unfortunately.
: Andy
: : - Your jumper IS set to ALT, not MAME, right?
: : - Key code for F7 shows as 118 on the IPACUTIL screen?
: : I use a shifted key for mine so I haven't tested it.
: : I'll test it over the weekend and let you know.
: : Bren...
: : : I'm having problems getting the IPac to work with the F7 (load) key. I have been able to program every other key fine, but for some reason F7 just doesn't work. It shows up in the ipacutil, but doesn't work in Mame. Pressing F7 on the keyboard works, so I know it just isn't mapped wrong in Mame.