Project xLA is coraboration Optimize and TeamKNOx.
What's it ?Connection method between PC and GBA.
xLA is a general term as PLA and ULA. PLA is an acronym as Parallel Linker Advance. Also, ULA is USB Linker Advance.
What do they do ?Downloading home brew software to GBA(Internal RAM...MultiBoot and FlashROM Cartridge as 256MPro from Visoly) with Host software.Of course you can suck-up program from your commercial cartridge to your PC.
How to get it ?PLA is aleady released(sold) from site of Optimize (Unfortunately, only Japanese-page). I made ULA by IPI EVA-board. Then add GBC/GBA adaptor board(very simple and easy) which is created by my self.
Optimize released new type and pretty good EZ-USB Evaluation board kit for rest of us. Only 3,000 JPY (w/o shipping & handling).
You have to add 26pole pin header(male) component connection for GBC/GBA adaptor.
You provide 26pole pin header(female), small PCB and all wired GBC/GBA connection cable.
You can customize your owned equipment which is used AN2131SC(EZ-USB) device. Picture shows USB-PDC by I/O Data Corp. I customized it and use.
ULA running sequence is little bit complicated. However, you can understand with sequnce diagram and souce code of ULA.
Over view shows connction each equipment.
Firmware(gba_boot.bix designed for EZ-USB as AN2131SC) is downloaded to EVA-board. EVA-board starts with new USB-ID and new role from previous setting.
1.5BIOS is special routine for GBA. Designed by Optimize. It is hard coded in firmware of ULA(as gba_boot.bix). Main role is fast communication driver with 32bit sync. mode. Why we call 1.5BIOS ?? GBA has its own BIOS. We should call it 1st BIOS. 2nd BIOS is should be more flexible... 1.5BIOS means both it is not 1st and 2nd ...
2nd BIOS is very flexible and main feature of xLA system. You can find out fwlib.bin in you ULA host software directry. fwlib.bin is 2nd BIOS self. fwlib.bin is designed by Optimize.
Communication established. You can control GBA via xLA.
You have to ask Opitimze, if you use 1.5BIOS and 2ndBIOS(as fwlib.bin) in your code. Also ask me if you use firmware of ULA.
Mootan developed very nice xLA handling software as FlashManager. Thank you Mootan !!It can support xLA system as same level as commercial software.
These downloadable stuffs had been little bit obsoleted at moment. (I recomened to use FlashManager if you use FlashCart with commercial softwarez.) However, you can easyly understand, then just started to hack ULA system !!