Screen flip for SNK Athena


At the request of a friend I was asked to fix the inverted screen issue with Athena.

An hour or so at the hands of the MAME debugger and a couple of false attempts the resulting patch is a simple two byte change to the rom.

In rom up02_p4.rom change these bytes. (actually, the patch swaps them around)

$029e to $48
$02a4 to $3e

Burn a new 27c128 rom and its done. Since we are swapping two bytes, the checksum doesn’t change.

Edit: Tested on a real pcb. Works perfectly as expected 🙂

7 thoughts on “Screen flip for SNK Athena”

  1. Hello

    Yes, i want to know if if your “high score save” eproms program who saves over 10 millions points for Juno First is still available ?
    I am interested.
    If you want, you can contact me by mail.


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