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

[Allen Huffman]

> On Jan 29, 2023, at 8:19 PM, RETRO Innovations via Coco <coco at maltedmedia.com> wrote:
> 
>>> Do you have a pointer to what the Commode disk drive serial protocol was like?
> 
> It's complicated:
> 
> On the bus (assuming device #8):


Yeah, that doesn’t sound like it at all. If we had seen any of the control bytes the same, there might have been some link to the origin of 1977 DLOAD and the serial load used by those drives, but it doesn’t appear to be the case.

P.ACK - Acknowledge - C8 hex.
P.ABRT - Abort - BC hex.
P.BLKR - Block request - 97 hex.
P.FILR - File request - 8A hex.
P.NAK - Negative Acknowledge - DE hex.

Did Microsoft create that code for the Commodores? Were there any other systems Microsoft did BASIC for that used a similar smart serial drive?

There are clearly some functional parallels in concept, so maybe there was some inspiration one way or the other.

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.

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Allen Huffman - PO Box 7634 - Urbandale IA 50323 - 515-999-0227 (vmail/TXT only)
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