ECS Keyboard, FWDiagnostics and Emulation

[+llabnip]

Greetings Programs!

 

Okay... so I've been getting back to Nintellivision (an Intellivision emulator for the old DS/DSi hardware) and adding in some new features - mostly around the ECS. Everything seems to be working well - ECS page-flipping and memory all good... and I thought the keyboard was good until I tried to run the 128K text Adventure (Advent.bin + .cfg) demo where the keys were nonsensical.  A few dozen google searches later and I find @intvnut's amazing posts explaining the keyboard, the ghosting problems and the 'transposed' method of scanning which the old Bliss core didn't handle. So I added that and magically the keyboard now works in every game including the Advent demo.

 

But I can't seem to get any keys to register in FWDiagnostics (which otherwise has been great to test the ECS stuff out... mostly the extra PSG sound channels and balance that volume with voice). When I select the ECS keyboard I can internally 'see' the traditional keyboard scanning (that is, 0xF8 & 0xC0 is 0x40 so it's not trying to use the transposed column/row scanning) but nothing seems to be returned / shown on the screen. However, if I press enough keys fast enough (on the DS by zooming my finger across the touch screen), I can cause FWDiagnostics to start displaying garbage. 

 

Now... let's be clear:  this is a bug in my emulation I'm sure!  FWDiagnostics is amazing and works fine on JZINTV.  I'm mainly trying to get my emulator in better shape - so if anyone has any clues or even rough guesses, that would help me go in the right direction!  Sometimes even the smallest clue will uncover the emulation issue I've got.

 

Thanks in advance...

 

Pics of the ECS keyboard screen before and after the 'glitch' (and never does it actually show any key being pressed):