Bringing up a CPM

From: Don Maslin <donm_at_cts.com>
Date: Thu May 27 18:48:16 1999

On Thu, 27 May 1999, Dwight Elvey wrote:

> It does on my system unless I toggle in a loader or have
> EPROMs to do it. I'd like to not have any EPROMs if I don't
> need it. The controller automatically loads track 0 sector 1.
> I start executing at address zero and it boot loads the
> CPM system. The boot loader then jumps to the start of
> the CPM and it over writes info at address zero with what
> it requires there. As far as I know, I am following the examples
> for a non-MDS800 type system and following exactly what is
> shown on 6-14/6-15 of the CPM manual that I got from the
> unofficial site. The mapping shows that the first sector
> is a cold start loader and the CPM ( CCP ) part doesn't start until
> the second sector.
> It would seem that there was additional BOIS info loaded that
> didn't fit into the 51 sectors. It sounds like I can ignore
> this because I'll be replacing it anyway.
> Let me say, no EPROM's, boots from disk.

Dwight, in looking at an Imsai disk that I have here - which has Imsai
CP/M v1.33 on it - the BIOS begins at sector 19 and ends on 24.
Presumably, you are working with v2.2 so Tim's quote from the DRI guide
certainly follows as 2.2 is most certainly larger than the prior versions.

The directory is skewed and the first file recorded is interleaved with
it.
                                                 - don
 
Received on Thu May 27 1999 - 18:48:16 BST