Space Ace Rev. A3 ROM image

Dumped by Warren Ondras - warren@dragons-lair-project.com
7/20/01

Notes from Jeff Kulczycki - jeffkul@dragons-lair-project.com - The only change in this ROM revision is in U1.

There are only four bytes that are different between ROM revision A2 and A3.
The first 2 bytes that changed are the checksum, which simply accounts for the other 2 bytes that changed.
The other 2 bytes that changed are the pointers to the RAM locations that store the scene pointers.
It seems they were using A070-A08F to save these pointers but they corrected themselves and moved these pointers to A080-A08F.
This was changed because there were some data already being stored at A060-A072, causing an overlap of two bytes.
The two locations that overlap are A071 and A072.
In one case these locations only get used if Player1 makes it to some of the highest levels (not sure which ones in particular).
And in the other case these bytes store the order of which scenes to play.
So, if Player1 was making it torward the end of the game and Player2 was still at the beginning then all hell would break loose.

For a description of what actually happens to the game and the steps to take see actually see this bug when using ROM revision A2,
check Tony M. Victorino's post on the Dragon's Lair Project message board at the link below.

http://www.dragons-lair-project.com/community/forums/board/default.asp?Action=View&MessageID=24150