Linked by Thom Holwerda on Tue 15th Jan 2013 22:29 UTC
Hardware, Embedded Systems "In this article, I show at the transistor and silicon level. I've discussed the mathematics of the 6502 overflow flag earlier and thought it would be interesting to look at the actual chip-level implementation. Even though the overflow flag is a slightly obscure feature, its circuit is simple enough that it can be explained at the silicon level."
Permalink for comment 549033
To read all comments associated with this story, please click here.
RE: Comment by Kroc
by Valhalla on Wed 16th Jan 2013 16:30 UTC in reply to "Comment by Kroc"
Valhalla
Member since:
2006-01-24

I did some brief programming on the 65816 back in the day (it was used in the Super Nintendo amongst others).

I remember going like 'yay, a 6502 with 16-bit registers!', unfortunately as I recall there were no separate opcodes for using 8 or 16 bit registers so instead you had to switch between 8/16-bit by setting a 'mode' bit in the status register with rep,sep instructions which quickly became tedious.

Reply Parent Score: 2