Is 65816 still "try it when feasible"?

[BruceMcF]

A long, long time ago, in a Galaxy far away, when the 65816 with detecting of the bank address was abandoned for the 64K memory map, the suggestion was made that when the time was right, y'all would see if the 65816 would work by just ignoring the bank address and adding the required pull up resister on pin3, which is a Phi1 output in the 65c02 and an /ABORT input in the 65816.

(Then, for example, if the CPU is socketed, those who wished to have a 65816 system could get a 65816 and make the swap themselves.)

It seems like the project is within one or two iterations of being at that point, so I was wondering if that was still on the timeline.

 

[AppliedCryogenics]

I hope it is! I am disappointed about the Commander X16 every time I watch "8-Bit Show And Tell" demoing a C64 with a CMD SuperCPU and ram expansion.  Those expansions, if released as the next-gen, low-end machine from Commodore, could have saved the company! 

I know the Super CPU came out in 1997, a couple years after Commodore tanked, but C64's were sold until 1994, and the 65816 had been in the Apple IIgs since 1986.  It wasn't such a big leap--  If they had the foresight to update the C64 line, around 1992, to add 65816 and 1+ MB of RAM, I believe it might have kept the company afloat for a while.

When I try to picture the X16 as this magic Commodore-saving product, I just don't see it. The upgrade is too incremental, considering what was cheap and available in 1991.

There are hassles involved with using a fast CPU with vintage on-board peripherals like a SID or a VIC chip. The SuperCPU got around this by using clock-stretching when accessing slower chips on the bus:

 

 





 

[paulscottrobson]

On 7/12/2020 at 12:59 PM, BruceMcF said:

A long, long time ago, in a Galaxy far away, when the 65816 with detecting of the bank address was abandoned for the 64K memory map, the suggestion was made that when the time was right, y'all would see if the 65816 would work by just ignoring the bank address and adding the required pull up resister on pin3, which is a Phi1 output in the 65c02 and an /ABORT input in the 65816.



(Then, for example, if the CPU is socketed, those who wished to have a 65816 system could get a 65816 and make the swap themselves.)



It seems like the project is within one or two iterations of being at that point, so I was wondering if that was still on the timeline.



 

About as much chance as it being personally delivered by Luke Skywalker I think. Timing is apparently an "issue"

[BruceMcF]

On 12/24/2020 at 1:18 AM, paulscottrobson said:

About as much chance as it being personally delivered by Luke Skywalker I think. Timing is apparently an "issue"

Is timing still an issue with the 65c02 or have they got the board to boot up?

The way to find out whether a 65816 works once the 65c02 works is to add the pull up resister and try it.

 

[StephenHorn]

8 hours ago, BruceMcF said:

Is timing still an issue with the 65c02 or have they got the board to boot up?



The way to find out whether a 65816 works once the 65c02 works is to add the pull up resister and try it.



 

The lack of news is frustrating, but I assume it means that nothing has changed and the team still hasn't been able to get the new board to boot up. And any crowdfunding announcement would probably be Q2 of 2021, at the earliest. Depending on their level of frustration, I wouldn't be surprised if they were redesigning part of the board at this point in the hopes of avoiding whatever pitfalls sunk the current one.

[rje]

8 minutes ago, StephenHorn said:

Depending on their level of frustration, I wouldn't be surprised if they were redesigning part of the board at this point in the hopes of avoiding whatever pitfalls sunk the current one.

For what it's worth, that's what I'm thinking as well -- they'd eventually backtrack into some redesign if things were serious enough.  I just had a thought that starting from a VIC-20 architecture is a good idea from a cleanness point of view, but might not be helpful from the speed POV.

There's probably not enough juicy info to release an update, much less an 8 Bit Guy episode about it.  But their current impediment will undoubtedly be part of the eventual story.

Although... now that I think of it... it seems that the 8 Bit Guy doesn't produce a video until he's gotten to a certain point.  For example, Attack of the PETSCII Robots.  His personal update schedule is based on internal milestones.

 

[Perifractic]

We're not posting an official update until we have something more conclusive but just to put rest to this conversation and any speculation here, we have had some fantastic successes very recently and the machine is all but fully working. Just a few little tweaks to fix. So things are looking really great and will have a full update for you very very soon. [emoji4]

[StephenHorn]

2 hours ago, Perifractic said:

We're not posting an official update until we have something more conclusive but just to put rest to this conversation and any speculation here, we have had some fantastic successes very recently and the machine is all but fully working. Just a few little tweaks to fix. So things are looking really great and will have a full update for you very very soon.

Thank you Peri! That's very exciting to hear! ?

[m00dawg]

Yes indeed! I got SUPER nervous when Dave nixed the X16 port of PETSCII Robots. I have no issues with setbacks for sure but the lack of information has kept me super worried. Even if the issue was having to completely re-engineer the board, that's at least an update. Very excited to see what is in store and thanks for the short but valuable update Peri! Helps put my mind at ease as we end 2020, a year I'm sure nearly everyone is glad to see nearly over!

[peon501]

I got the same vibe with PETSCII Robots cancellation on CX16.