simple 68k loop

Ask anything your want about Megadrive/Genesis programming.

Moderator: BigEvilCorporation

User avatar
Very interested
Posts: 709
Joined: Thu Apr 10, 2008 3:03 pm

Re: simple 68k loop

Post by Sik » Thu Oct 11, 2018 8:37 am

bioloid wrote:
Wed Oct 10, 2018 6:15 am
and this one doesnt save bytes, it looks like it's unrolled at build time

Code: Select all

.rept 62
	dc.l    _INT
But that's precisely what you want (there are 64 vectors, two of those are reset and entry point, the rest are interrupts). But yeah, that's pretty much the same thing dcb would do.

Anyway, there's what Miquel said if you really want to save bytes, but honestly I wouldn't get too hung up over saving bytes in the 68000 vectors (especially if you intend to use the vblank or hblank interrupts later, as they end up in the middle of the vector table...) The last 16 vectors (64 bytes) are pretty much unused tho so feel free to put garbage there.
Sik is pronounced as "seek", not as "sick".

Very interested
Posts: 107
Joined: Fri May 18, 2012 8:22 pm

Re: simple 68k loop

Post by bioloid » Thu Oct 11, 2018 4:39 pm

Sik you are right, for a 4k I would need this blanks interrupts anyway, nevertheless I find what Miquel taught is awesome!

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest