[Coco] My coco3 gallery

[Phill Harvey-Smith]

Bob Devries wrote:
> Phill Harvey-Smith said:
> 
>> That's cool...guess I should post some piccies of my CoCos/Dragons at 
>> some point.....
> 
> Please do. I'm always interested in other computer systems, especially 
> those which were very uncommon, like the Dragon. I don't think the 
> Dragon was ever sold in Australia.

Yeah I think they where only sold in the UK, Spain, once DragonData 
where sold to Eurohard, and under license by Tano in the USA. If you 
want to see some piccies of some of the rarer Dragons, then check out 
http://www.dragondata.co.uk

>> You don't happen to have the schematic for the lower case mod do you 
>> (and a dump of the character rom), I'd like to have a go at making one 
>> of those sometime.
> 
> I'll see what I can do on that score. I don't have a schematic, but it 
> shouldn't be too hard to produce from the PCB.

No, having looked at the data sheet for the 6847, I think I could 
possibly work most of it out, I can see several chips apart from the 
6847, the character ROM, a LS161, which seems to be used to scan each 
line of each character, an LS245 buffer, a LS86 quad XOR gate, which I 
assume turns off the extra circuitry when in non-text modes, and another
chip which I cannot see the part no on :)

> I can dump the contents of the character ROM (if I don't already have 
> it) on my EPROM burner. 

That would be cool, If you can take a good picture from directly above 
and directly below the board I can prolly trace tracks from there :)

>			The PCB sits in the socket of the 6847 VDG chip, 
> and the chip is plugged into the PCB.

Yeah I have produced several boards using this method, for adding extra 
stuff (especially in the Dragon Alpha/Professional clone).

Cheers.

Phill.

-- 
Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !

"You can twist perceptions, but reality won't budge" -- Rush.