I think moving the PS/2 keyboard handling to a microcontroller is the right thing to do in this case.
Yes.
I don't know for the current design, but AFAIK the Vic20 and C64 do not use NMI - it appears to be connected to RESTORE. An NMI would not be suitable for keyboard polling per se perhaps, there may be some hardware accesses that it would mess up, but you could make it an IRQ with a pull up transistor or something. There are pretty stable i2c libraries and ps/2 setups for AVR chips, so it shouldn't be difficult to make what is effectively an i2c keyboard.
Well .... this board seems to have more microcontrollers than Digikey these days.
Hmm, off the top of my head, I can only think of the ATTiny and what looks like an STM32 on VERA. The ATTiny handles the ATX power sequencing and potentially the PS/2 keyboard and mouse. I'm not certain about the STM32 on VERA, but I think it is used for programming the FPGA's SPI flash so it isn't strictly necessary. Is there anything else?
Hmm, off the top of my head, I can only think of the ATTiny and what looks like an STM32 on VERA. The ATTiny handles the ATX power sequencing and potentially the PS/2 keyboard and mouse. I'm not certain about the STM32 on VERA, but I think it is used for programming the FPGA's SPI flash so it isn't strictly necessary. Is there anything else?
My guess is that the community is not interested in the keyboard solution per se. We just want it to become functional so that we can get on with what really interests us, eventually owning and using a X16.
I agree that the team should choose a proven design that is easy to implement.
@Wavicle, do you see any problem supporting both keyboard and mouse with the ATTINY + I2C solution?
More or less true for me, with the one exception being that I'd like the ability to send messages to the mouse so that Intellimouse mode support is possible, even if not via the Kernal.
In Facebook group Lorin Milsap posted some info. Lorin is part of the extended X16 team but not in the core development team. In Facebook group Lorin has badges of Admin, Group expert and Founding member.
In Facebook group Lorin Milsap said:
Consider this as a semi official response.
As stated by others earlier yes there are 2 hurdles. The first is parts availability. This is highly affected by Covid and global supply chain issues. I won’t cover specifics, but many of the parts in short supply are the common logic chips.
The second issue is the PS/2 keyboard code. There is an updated routine which supposedly works, but none of the design team who has real hardware has had an opportunity to test the new code. Keep in mind by real hardware I mean complete machines that meet the current design criteria, not past revision boards. This actually circles back to the supply chain issues (yes it’s that bad). To my knowledge only 2 fully functional current boards exist, possibly a third, and no I do not even have one.
