[Coco] DLOAD upload program for CoCo 1/2?

[RETRO Innovations]

On 1/29/2023 11:22 PM, Allen Huffman via Coco wrote:
> Did Microsoft create that code for the Commodores? Were there any other systems Microsoft did BASIC for that used a similar smart serial drive?

In the early years, according to pagetable.com (excellent source of MS 
BASIC information), MS made the changes for the very early systems, but 
then started just supplying the source for the CPU of interest and 
letting the companies modify themselves.

In the time they made all the changes, I think Atari is the only other 
company that had a "logical" drive concept, and they wrote their own 
BASIC.  Tandy, Apple, Coleco, the S100/CPM folks, and TI all had a 
controller hardwired to the CPU and implemented disk access directly.

> There are clearly some functional parallels in concept, so maybe there was some inspiration one way or the other.
Well, as I noted, I think CBM's bus was inspired by HP's interface bus 
(IEEE 488 started life as HPIB as it was on all the HP instruments, 
which is where Chuck Peddle saw it, loved it, and managed to convince 
Jack to allow it to be used on the PET). I assume DLOAD had some similar 
heritage.  It's a cool question, I'll check on the Classic Computers 
mailing list (which deals more with minis and such and see if the codes 
ring any bells)
>
> The DLOAD document from 1982 calls it:
>
> Microsoft 6809 Extended Color BASIC
> DLOAD/DLOADM Communications Protocol
>
> That makes it sound like, if DLOAD existed on other systems, this protocol was different on the 6809.

It does.