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Curious that it works in a D32. Can't really say much else without seeing a schematic and more detailed measurements.

Assuming you've followed the build instructions to the letter, the ball is very firmly in the court of the supplier and/or designer.

I would use an oscilloscope to see how much ripple there is on the supplies. The fact that it works when more current is drawn suggests one of the supplies is moving to a more stable region, which in turn suggests an incorrect component value. A component value could be incorrect because it was put ...

Hmm, strange one. In my experience, jail bars on Dragons are usually caused by missing bypass caps on the DRAM array, and fitting all eight 100n caps virtually eliminates them. I don't think I've ever seen hum bars on a Dragon. That tends to indicate a fault, particularly if you say 1u caps didn't m...

Love the artwork! Brilliant

Cool. Thanks for sharing :) There is an old trick for converting a binary digit to ascii hex that is fewer bytes than the branching version: adda #$90 daa adca #$40 daa Also, I wonder how the long multiplication compares with a version that uses 6809 MUL (8x8) to generate the partial products.

Doesn't RTI spit a dead cycle at the end though?! It does, but the beautiful thing is that it emits the stack pointer during that cycle rather than FFFF :ugeek: Something similar happens to allow say LDA ,X to work. It runs for four cycles: First two cycles are opcode and postbyte, then there is a ...

Not quite sure where this lies on the filthometer, but one code trick I'm fond of is using rts with a preloaded stack as a fast loop counter or sequencer. A similar thing can be done with puls regs,pc to quickly make a series of function calls with parameters. This approach is nicer because it respe...

Just some proof of concept code to access the rtc without switching roms.

Should help with getting one of these working in a Dragon 32.

That's some pretty tenacious coding you've pulled off there to access the rtc

The hi score table looks great, and I don't even need to add the qualifier 'for the Dragon'! It definitely captures the arcade feel