[TI ASM] Writing to port $21

[King Harold]

Writing to port $21..
What does it do? WikiTI says:

Write Values

* [00h - FFh]: New value for the register

It also states that there is no reason to write to it, and nothing can make me more curious then that
I tried to write to it a few times, no crash or anything, but nothing seemed to happen at all.

Code: Select all

	ld b,255
	ld a,$C9
-:	out ($21),a
	djnz {-}
	ret

So I wrote 255 $C9's but they did not appear anywhere I could check

[Jim e]

$21 is protected. To write to it you must unlock the flash.

For what it actually does see the talk page.

There are still some ports I couldn't figure out or were boreing. You can read them up here.

[King Harold]

Ok thanx, but I don't really understand that.. what happens when you write to it? it changes the execution protections?

[anykey]

darn. I thought somebody was paying for a port of a game, but no...just asm chatter!

[King Harold]

lol

[Kalimero]

...see the talk page.

Woah, August 2005, has it been that long...

There are still some ports I couldn't figure out or were boreing. You can read them up here.

Hmm, 0B and 0C. What about timeout value for receiving and sending?