[Coco] New version of SDC-DOS available

Allen Huffman alsplace at pobox.com
Fri Dec 2 13:41:43 EST 2016

> On Dec 2, 2016, at 12:35 PM, Philip Zeigler <philip at zeiglers.net> wrote:
> Thanks Allen…I don’t like having the separate boot and hard disk images so I will look into your solution.

When I get my CoCo set back up (hopefully over this winter), I will write a custom utility that will automate all of this. I just have to decide if I want to write it in assemble, C or BASIC09. Maybe I'll do it in all three and write a companion article about that.

The basic idea is:

1. You have to have the track 34 sectors on the hard drive .DSK available, since that's were the boot ("DOS" loader) goes. If you already have data using those sectors, you can't do it, BUT you can make a fresh, blank image and make it bootable, then copy all your stuff to it.

2. You copy the kernel track from an existing boot disk to the hard drive disk, and mark those sectors as "used" in the Disk Allocation Map.

3. You copy os9boot to the disk image, then edit a few bytes in the first Logical Sector 0 of the hard drive to tell it where os9boot begins and how big it is.

That's really it. But it's tricky if you haven't worked with the dEd disk editor before. I have screen shots and such in my article, and a BASIC09 program to copy the DOS boot track over (but you have to edit LSN0 and the DAM manually in dEd, which is what I want to automate).

		-- Allen

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