[Coco] f83 for the 6809 -- It'a Alive!

[Darren A]

On 10/17/08, tim lindner wrote:

> ....
> .... with DSKCON comes a large portion of BASIC and
> it's overhead. Whenever I imagine I'm in a position like Brett, I'm
> always ripping DSKCON from the ROM and make it independant.
>

What "large portion of BASIC and it's overhead" are you referring to Tim?

The Tandy versions of DSKCON are almost completely self-contained.
Other than 2 calls to a short delay-loop subroutine in COLOR BASIC at
$A7D1, there is no reliance on any other BASIC routines.

Tandy's DSKCON does require use of the following RAM addresses:
008A - 008B:  Assumes these two bytes are always zero
00EA - 00F0:  The documented DSKCON parameter block
0109 - 010B:  NMI Vector (jumps to Disk Basic's service routine)
097E - 0986:  Variables  (TRKTBL,NMIFLG,DNMIVC,RDYTMR,DRGRAM)

Other implementations of DSKCON such as those used in RGBDOS / HDBDOS
and DriveWire may have different requirements that I am not aware of.

Darren