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What kind of glitch are you seeing on PAL - is the screen rolling or is it the weird coloring at the top of the screen? Chris

My kernel requires DPC+ also - it is very similar to the previous approach, I just reorganised things a bit to avoid the vertical gaps. Bus stuffing should allow the ball to be removed, and the lines to be individually coloured. The blank line between rows is artificial - there is no need for any horizontal or vertical gaps. Chris

What is the LifeSpan box - is your desk above a treadmill? Chris

Nice - the vectrex is a great system! I have one too, and it seems made for a Juno First port Chris

It should be possible, but there are very few people with the necessary skills and time. Here is a funky tron logo (designed by Nathan Strum) while you wait. Chris tronlogo.bin

Perfect timing - I was just thinking about doing a small DPC+ARM project to get back into 2600 programming and I was struggling to remember how it all fitted together - thanks! Chris

Try a different TV - it looks like it is having problems with the technique used to display the menu. Chris

Ah - it is probably an MMC card rather than an SD card. There was a bug in the MMC protocol that is fixed in the upcoming bios 0.6. I'm looking forward to seeing your projects! Chris

I'm glad to hear that you got it working. Some SD cards don't stick fully to the spec. What make and size was the card? I hope tthis means you are returning to Atari 2600 programming?! Chris

Thanks for posting the link - that is a really thorough analysis of Tetris! I did attempt to duplicate the gameboy timings and distributions for Chetiry, but there are probably lots of subtle differences. I haven't seen such obsession with the game since I saw this video: Cheers, Chris

Yes - the harmony cart will work on a PAL 2600jr. Chris

It sounds possibly like a problem with the edge connector on the Harmony cart. Has the edge connector got scratched or dirty from the floppy cable? I'd try carefully cleaning the edge connector and cartridge port on the Atari. Also the circuit board in the Harmony cart can become unseated - make sure that it is straight and making good contact with the Atari cartridge port. Chris

I would also like the standalone version. Chris

For Chetiry, I used a customized version of the DCP+ fast fetchers to update the audio in 5 cycles, i.e: lda #<AUD0 sta AUDV0 However, if you are already getting tight for cycles it is probably best to save them for the actual game Chris

I suppose you could use the extra 5 cycles for digital music or SFX? Chris

The cycle 23 one could do the jmp a bit later , i.e. shift a bit more code into the bank containing the kernel entry point? Chris

Nice work - this has to be for a Robotron kernel It feels like it might be possible to optimise further by removing the following two lines: lda #<DS_JUMP ; 2 30 sta NextKernel+1 ; 3 33 If you could arrange all the kernel entry points to be in the same bank, and repurposed the cycles for the jmp R76, i.e.: KernelEntry1: jmp ActualKernel1 ActualKernel1: ... jmp (NextKernel) But those 5 extra cycles are probably not enough to update the PF or anything useful ... Chris

Try moving the difficulty switches to position B

Thanks - Chetiry generates the music using hardware in a similar way to the DPC chip used in Pitfall 2. However, Chetiry only generates square waves. Different waveforms (to simulate different instruments) are used in Stella's Stocking, and the upcoming Stay Frosty 2. Chris

Nice work - I like the vblank and overscan counters. How much work remains to turn this into the full game? Chris

I never registered that the Krokodile was a flasher - I just thought he was selling dodgy merchandise out of his coat Any idea why it was called the "Krokodile" cart - perhaps Armin just likes crocodiles? Chris

Thanks - I really enjoy reading these. It is great to hear the story behind the artwork, not just the programmers perspective. Chris

Good idea - I read through your gallery when you first posted it up, but I had completely forgotten about it. Chris

You should be able to make a good Robotron port with that kernel.

The most likely cause is an out of date or corrupt BIOS, but it could be an issue with your console. Have you tried any normal Atari carts 16K and over on your console, i.e. the actual cart rather than the Harmony? Chris