archive.worldofdragon.org

Well, in the latest snapshot, the instruction set is complete, but untested so probably very buggy - I look at my DIVD/DIVQ implementations with particular disdain ;) When I get a real part, I'll start comparing behaviour. After 30 years I would have thought that ALL members had at least one Dragon...

October is long gone. Have you installed them yet?

Thanks, Rolf!

Is it OK to simply wire pin 20 directly to Vcc, or does it need to go through a resistor?

Is that all I need to do to make the stacked EPROM work reliably?

Would it work (and be reliable) if I were to solder a 28 pin IC socket directly onto the legs of an existing board mounted ROM chip, seat a 27C128 EPROM in the socket, and disconnect Vcc (pin 28) from the original ROM chip? Would this method safely disable the original ROM chip, and give me a reliab...

BTW, the Rainbow magazine featured a column by Marty Goodman's Rainbow about a similar rom (although without the dual boot feature): "For a while some companies (such as Super Choc in Canada) sold CoCo ROMs modified for the Dragon, and the Los Angeles Users Group had a number of members running Dra...

Thanks for checking, Rolf. That's very useful information.

I always thought there were 8K and 16K game cartridges. Your findings make it look like 16K Dragon game cartridges may never have existed.

On which cartridge did you find this EPROM? I found two of the 4K EPROM chips in an original Dragon Data game (Starship Chameleon) cartridge. Does anyone know which ROM/EPROM chips were used for the twin 8K ROM game cartridges? Is it socketed? Yes, both are socketed. I have seen inside around half ...

Thanks! It would be handy if you could post a duplicate of this in the Hints and Tips section.

Regards,
Steve

Does anyone know which EPROM chips would be suitable direct replacements for the 4K (TMS2532-55 JL) and 8K (Unknown?) Dragon Game Cartridge ROMs?