Bringing up a CPM

From: Allison J Parent <allisonp_at_world.std.com>
Date: Thu May 27 18:19:44 1999

<> The first sector DOES NOT HAVE TO BE THE BOOT.
<
<Hi
< 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

That is an example of the MDS800 style of boot. It is also fairly
atypical of many.

<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.

Yes that config is specific to the MDS800 and that boot will likely
NOT work with any controller in a IMSAI. If the controller in the
imsai is the one I think it is (has an 8080 and an d372 FDC), the bios is
simplified as that one does a lot of the work.

I've built enough CPM system to have the configuration guide memorized.
However I stopped going by the book as it's actually a bit to terse and does
leave one to much imagination. The book by Andy Johnson-Laird The
Programmers CPM Hand book is a must have for anyone doing bios work.

Allison
Received on Thu May 27 1999 - 18:19:44 BST