I liked the index modes, with accumulator and auto increment/decrement.
The multi-byte push and pop off of the U register for block moves was nice.
And of course the best instruction in the chip was Sign Extend B into
A. That instruction was SEX in the Motorola assembler.
CLR B
SEX
was the same as
CLR A
CLR B
But then you could have sex in your code🙂
Hey, when I was in my 20's and programing the 6809 that was fun.
On 12/4/2024 1:14 PM, Nigel Johnson Ham via cctalk wrote:
On 2024-12-04 14:09, Tony Duell wrote:
On Wed, Dec 4, 2024 at 7:06 PM Nigel Johnson Ham via cctalk
<[email protected]> wrote:
[6809]
I agree. The user stack pointer was a killer feature.
I like(d) the progam counter relative addressing mode along with the
long branch instructions so you could write position-independant code.
-tony
Yes, a reminder of my pdp-11 days :-)
