[Coco] 6309

[L. Curtis Boyle]

Correct. The first version of Burke & Burkes Powerboost used emulation mode, with the extra instructions. 

Sent from my iPhone

> On Mar 27, 2017, at 10:43 AM, Arthur Flexser <flexser at fiu.edu> wrote:
> 
> Bill, I think the error trapping that you're describing is what happens in
> emulation (or native) mode when an illegal opcode (i.e., illegal even when
> 6309 added opcodes are included) is encountered.  According to others, a
> legal 6309 instruction is executed even in emulation mode.
> 
> Art
> 
>> On Mon, Mar 27, 2017 at 12:30 PM, Bill Nobel <b_nobel at hotmail.com> wrote:
>> 
>> What actually happens, is the 6309 will see that it is emulation mode and
>> cause a error trap.  The CPU will grab the address stored @ $FFF0 & $FFF1
>> and jump to it.  This was how the new instructions were discovered.  Users
>> of the 6309 thought it was a flaky 6809 clone because it would randomly
>> crash on a error.
>> 
>> Bill Nobel
>> b_nobel at hotmail.com<mailto:b_nobel at hotmail.com>
>> 
>> 
>> 
>> On Mar 27, 2017, at 10:04 AM, Arthur Flexser <flexser at fiu.edu<mailto:
>> flexser at fiu.edu>> wrote:
>> 
>> BTW, what happens if you're in emulation (non-native) mode and a
>> 6309-specific instruction is encountered.  Is it executed, error-trapped,
>> or what?
>> 
>> Art
>> 
>> On Mon, Mar 27, 2017 at 10:54 AM, L. Curtis Boyle <curtisboyle at sasktel.net
>> <mailto:curtisboyle at sasktel.net>>
>> wrote:
>> 
>> Just to clarify - you see around a 10% speed increase just by turning
>> native mode on. You can see a much bigger increase for code written
>> specifically for the new registers, new instructions, block memory moves,
>> etc. (like the 6309 version of NitrOS-9).
>> 
>> L. Curtis Boyle
>> curtisboyle at sasktel.net<mailto:curtisboyle at sasktel.net>