Encode or Decode?
Another question I asked myself, was about the controls. Should I use a keyboard-encoder, like the KE-24 from Hagstrom Electronics, or should I hack an old keyboard ?

Programming the LP-24I decided to go for the keyboard-encoder, as my cabinet will already cost me a lot of money, and I want to do it right. Using the keyboard-encoder, I will have less ghosting problems. I already have broken 3 keyboards, trying to find a 30 key setup with almost no ghosting (soldering is not my strongest point).

Next thing to do is choosing between the LP-24 and KE-24 encoder. The KE-24 has a RS-232 port, and can have macro's of up to 16 keystrokes. The LP-24 lacks the RS-232, and macros can be two keystrokes only (CTRL, ALT of SHIFT+other key), and is $20 less. I decided to go for the LP-24, because I don't need the macros or the RS-232.

On Saint's page, I found a nice matrix for 30 key's:

  1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16 17  18 19  20  21  22
A U1 L1 11 21 31 41 51 61 U2 L2 12 22 32 42 52 62 P1  P2 C1  C2  RST PAU
B D1 R1                   D2 R2                   TAB ~  ENT ESC
Ghosting is almost impossible with this setup.

The configuration-file for the setup above is here (pc2jamma.cfg), ready to use with the LP24cfg-program. I changed my setup a bit afterwards, due to some MAME-specific button-placements. The standard-contols weren't changed however.