Tuesday, June 24, 2008

Damn those NEC people!!

I've been updating my assembler to do the extra TG16 opcodes I need only to discover that NEC in their infinite wisdom have changed every opcode! Every single one! Damn them!! So I now need to create another opcode table for the PC Engine.... Bugger. It also means it's going to take me a little while before I can get to actually work on the blood thing.

I found another old PC Engine manual though, and its the good one! It has all the hardware and CPU stuff which means I can at least start to read about things - even if i can't plunge on and program anything!

While I do want to play with a dual-playfield thing, I suspect I'll end up porting XeO3 to it coz...well... why not. The TG16 was a shooters dream machine and had some amazing shooters on it, so it will be good to actually write one on it. Shadow of the Beast let me code this little machine and I do love it... but I hated almost every moment as the game was totally crap. Oh well....

4 comments:

David said...

You might want to take a look at MagicKit, an open-source asssembler for PC Engine. And HuC, into which MagicKit has been integrated. There are well-commented libraries written in assembler as part of that package (which can be found at http://www.zeograd.com ). I know, because I wrote quite a bit of it...

Mike said...

I've had a look at that... Im not fond of segments and the like, and theres nothing really in the kit I need. I'll stick to my own as my assembler is well tested now and has some great features. Also if I need a new one - I can just add it! :)

tomaitheous said...

Do you scans of the manual and would you be interested in sharing it? I have some official dev examples/source but no manual. I love looking through old dev kits and manuals, especially for the PC-Engine and for that era. Through one of the official source code we figured the name of VDC register 3 and 4 which seemingly have no effect. Charles Macdonald found out that those two regs are used for when there is not VCE and the VDC drives the output sync signals (like the arcade Bloody Wolf that uses a modified PCE and no VCE). The two regs are for palette accessing palette data when running without the VCE.

Mike said...

Sorry I can't. I'm technically still under NDA for all this stuff. The only stuff i can release is stuff thats already been discovered, and then its kinda pointless :)

And even then, I cant just scan and release the offical doc's as they are still under copyright.