archive.worldofdragon.org

I found another funny thing :mrgreen: When operating the disk drive (which is funny because you cannot have the disk cartridge and the midi cartridge together unless you have a MPI or similar device), the program tries to OPEN"I",#2,"LARGO.M10" which in the Dragon results in a ?DN ERROR Where can I ...

I also found this: https://github.com/go4retro/MIDIMaestro Which references the Rulaford MIDI Interface, could that be it? Looking at the V1 schematics, which should be closer or that of the original cartridge, turns out that address bits 5,6,8,9,10,11,12,13,14 and 15 are fed into the 74LS133 NAND g...

Heh, The code is writing to port &HFF74 as if it were a control port and &HFF75 like a data port: 440 :'PLAYBACK 450 CLS:GOSUB 90 455 T2=60000/TEMPO 460 POKE&HFF74,3:POKE&HFF74,22 :'SET MIDI 470 POKE&HFF75,207:POKE&HFF75,NS:'STYLE 480 INPUT "ENTER TO START";ST 490 FOR J= 0 TO 3:'VOICE 500 POKE&HFF75...

Maybe it controls a cartridge hosting a midi device?

The program is written in Basic, so we could take a peek...

Behold!

A fully assembled Dragon Beta board!

I need to make a video cable and probably use my trusty Meanwell PSU to power it. Fingers crossed...

This is going to come in handy, thanks a lot!

Welcome to the Dragon Archive! I had a similar problem with a CoCo2, and turn out to be a bad MC6847 video chip. Other culprits could be the roms. If they have given up their ghost and become corrupted, you could get a bad video initialization. If you type CLOAD and press Enter, do you hear the rela...

They sound really good and the lyrics are fantastic

I think the title already spoils all the fun, so here you have it!

I think it's very well researched and unbiased, plus it introduces the reader to some considerations that aren't always on our minds, like why the -5/-12v regulator is not attached (and why it shouldn't).

Thanks!