Commander X16

5 minutes ago, Perifractic said:

We have a dedicated feature requests forum: https://www.commanderx16.com/forum/index.php?/forum/14-x16-feature-requests/ (or find it under the Support menu)

done! 

On 7/6/2020 at 1:16 PM, -N2 said:

it's almost as if it was daring you to plug the cards in backwards. 

I think it is rather assuming (and probably correctly) that given the wide range of technical backgrounds in its audience ... there WILL be people who WILL plug cards in backwards.

I wounder what the mechanical interface would be.



Given the approach to "low cost off the shelf components", I'd assume one might use ISA connectors for that, since they are still being made and widely available at reasonable prices.



In order to prevent someone from sticking in an ISA card, which will be incompactible, it might be useful to insert the slot 180° horizontally rotated and have it aligned so that expansion cards are oriented like PCI/PCIe cards, making installation of ISA cards impossible.



This way, production of said expansion cards would also be cheaper - espechally when they do want to provide I/O outside of the case [like a network controller/"transparent modem"]...



Also since ISA edge connectors are relatively big and chunky, they also lend themselves as a good basis for people who might want to DIY and prototype said expansion cards.



Not to mention that additional pins of a 98-pin connector might also allow additional voltages or connection options to internals - i.e. IEC or joystick ports or serial ports or even audio, thus making modifications even easier as well as allowing more modularity and upgradeability without sacrificing the minimum viable goal.



Personally, I do know someone who might be interested in developing some FPGA-based accelerator for the X16 and having some expansion interface ready early on will greatly support both hardware and software development as well as making an independent aftermarket possible.

12 hours ago, Kevin Karhan said:

I wounder what the mechanical interface would be.





Given the approach to "low cost off the shelf components", I'd assume one might use ISA connectors for that, since they are still being made and widely available at reasonable prices.

The physical format is stated, it's the same as the Apple2 backplane connector. That is still in production -- even if it is more for the industrial market which also uses them than the Apple II market

5 minutes ago, BruceMcF said:

The physical format is stated, it's the same as the Apple2 backplane connector. That is still in production -- even if it is more for the industrial market which also uses them than the Apple II market

the more I think about it, I'm OK with it using a proprietary bus pinout with a connector compatible with the vintage Apple II, at least we can use the proto boards available for it! 

What's going on with the BUS_L and BUS_R pins on that header? Are these audio lines? Are you sending expansion audio from the cards to the motherboard?

14 hours ago, Wesley Mays said:

What's going on with the BUS_L and BUS_R pins on that header? Are these audio lines? Are you sending expansion audio from the cards to the motherboard?

Maybe they're business lines.  You know, business left, and business right... oh ok it was a terrible joke to begin with.

 

On 7/5/2020 at 4:16 PM, BruceMcF said:

That's a relief to see the +/-12V lines outside the VCC and +3.3v lines, rather than next to signal lines.

Also, I just noticed that they're mirrored... so, unlike some bus ports I've seen, plugging the card in backward won't immediately short VCC to the ground, or something stupid like that. 

Obviously, the card won't work, but it'll basically just muck up the address and clock lines, preventing the system from running. It doesn't look like a reversed card would blow up the computer or the expansion card. 

 

Does someone already have a KiCAD footprint for the card edge, or a drawing so I can create one?

1 hour ago, Terrel Shumway said:

Does someone already have a KiCAD footprint for the card edge, or a drawing so I can create one?

I may be wrong, but I think there's still no public information about any PCB because there's still nothing final and things can change. So, creating any piece of hardware for the platform at the moment is not possible.