Processor Instruction Sets

[Mike T.]

(09-05-2021 12:40 AM)teenix Wrote:  You might by the time you finish, which never seems to happen ;-)

LOL - you don't know how true that is...

If you look at some of the comments in my source code you will discover just how long I've already been working on this - though to be fair there was a bit of a gap in the middle (of about 6 years) but I in my defence I have been teaching my self C and X11 at the same time! (https://github.com/mike632t/x11-calc)

Looks like the P register is even stranger than I thought. Discovering that the binary value in to op code bears no relationship (that I can work out) to the value of P was odd enough. I can only assume that the way the registers arranged on the chip means the digits are not in order.

Mike T.