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

[Allen Huffman]

> On Jan 29, 2023, at 7:09 PM, RETRO Innovations via Coco <coco at maltedmedia.com> wrote:
> 
> This piques my curiosity, but I need more context on what "DLOAD-like" implies or means.
> 
> The LOAD/SAVE/OPEN/CLOSE/PRINT/GET/INPUT commands in CBM BASIC ride atop a set of commands that looks more like IEEE-488 commands to me.
> 
> It's possible the rarely seen CBM BASIC 1.0 which only had cassette tape support might have had a LOAD that aligns with DLOAD here.

Perfect! We needed a Commodore-experienced person on this one.

Microsoft’s DLOAD protocol was a load via serial. If it’s accurate that it first appeared in 1977, that would have it something they’d already have had around by the time of PET BASIC, I think. Though I don’t remember how the PET disk drives worked.

DLOAD would load a BASIC program, though a manual entry says it was in ASCII. I do not know if this is accurate, since another manual entry had DLOAD specified as machine-language, which it was not. That was DLOADM.

They could specify a filename, which would be sent to the remote device, and then it would send back the file in 128 byte blocks with an XOR checksum over the data and length byte. From casual glance, it looks like it always had to send 128 bytes so the length did not change how much was sent.

Do you have a pointer to what the Commode disk drive serial protocol was like?

DLOAD”$” then a LIST would have been very similar to LOAD”$”,8,1 then a LIST, provided that the other end sent back a file called $ the could be LISTED.

Actually, how did the directory work? I don’t remember it having line numbers at the start of each line, but I do remember one could cursor up a few lines and do a L+CHARACTER sequence (shortcut for LOAD) or something to quickly run something.

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