6809 (was: Anybody ever use Aztec C for APPLEII?)

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Apr 28 17:44:14 2004

>
> In hindsight, the 6809 while the best 8 processer it only has 64k of
> memory space. Time has proved the 64k data and 64k program space and

I am trying to think of a common 8-bitter with more than 64K of memory
space. OK, some microcontrollers have 64K program space and 64K data
space, I guess...

> about 1 meg of memory ( something the PC-XT had or PDP11/unix ) was
> needed for useful programs with a resonable OS. Also since the only
> common 6809 system was by Radio Shack as games machine you never got the

And its close relative the Dragon 32. Both were based on the same
Motorola application note IIRC.

> good I/O like lower case letters and a real serial and floppy drives.

Err, we are talking about the same CoCo, I assume....

It most certainly does have real floppies. Standard Western Digial
controller chip (1773 in my system) and drives. The buit-in serial port
is, agreed, a bit-banger (and best used as a printer output only), but
Radio Shack sold a proper serial cartridge based on the 6551 chip. I have
a homebrew version in my CoCo, with 3 6850s in it (3 serial ports...)

The video display was a problem on the CoCo 1 and CoCo 2. Of course under
OS-9 you could hang a serial terminal off one of hte serial ports. And
the CoCo 3 had a much better video system (pity it's almost unheard-of in
the UK).

-tony
Received on Wed Apr 28 2004 - 17:44:14 BST