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Welll...looking at the circuit diagram the Dragon paralell port has available the PIA lines that the CoCo uses for it's serial bit-banger, so you could in theory use this (with apropreate software) use the lines as a CoCo bit-banger port. You would of course also need a level shifter between the 5v/...

That is most excellent.....humm wonder if I could use bits of that circuit to make a colour board for my Acorn Atom clone (or the original Atom come to think of it) as they both also use the 6847 VDG.

Cheers.

Phill.

Bad luck with the 16K, but there are an awful lot of them out there. At least you didn't get an ultra-early 4K model. ;) (Or maybe they're worth more?) Yeah I believe so as the majority where upgraded..... Upgrading might be possible... And for the most part with a CoCo 1 which is what the OP has, ...

I have a couple of the voltmace sticks and they are quite nice also, as they are also self centering.

I believe they where also available for the BBC too.

Cheers.

Phill.

The Dragon Alpha also had one as standard (AY-3-8912), used it for sound and to control the drive selects on the disk interface. It would be possible to add this to a Dragon 32/64, but would require socketing one of the PIAs, and adding a second, the AY was connected to one of the ports on the 3rd P...

What puzzles me is that only the first of the two socketed chips have the "erase window". Maybe they used a mixed of EPROMS and non erasable roms? I have seen some EPROMS used in Dragon carts where instead of the sticker, the window was painted black. The other posibility is that the second chip is...

In short no.... for the following reasons: 1. The D32 and D64 power boards are slightly different although the later D32 PSU boards should work Though it is pretty easy to convert one to the other, by switching the 7912 regulator for a 7905, or vice-versa, 7912 is -12V for the 64, 7905 is -5V for t...