Bringing up a CPM

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Thu May 27 15:27:38 1999

> According to my DR "CP/M 2 Alteration Guide", track 0 sector 1
> is the cold start loader (bootstrap). Track 0 Sectors 2-17 are the CCP.
> Track 0 Sectors 18-26 and Track 1 Sectors 1-19 are the BDOS. And
> Track 1 Sectors 20-26 are the BIOS. This is for a plain-vanilla
> 8" SSSD installation, of course.

What the manual doesn't say (besides alot) is that the boot was specific
to the MDS800 implmentation and is optional! Afterall if you can read the
disk why read a boot unless the original rom boot was to read ISIS OS!
If your rom(eprom) can read the read teh boot device it can also load cpm
and do the coldboot work. That makes both the boot sector and parts of
coldboot routine optional.

For example one of my systems has CPM (CCP and BDOS) in Rom and the boot
rom copis the bios to the right address then ccp and BDOS below it and
jumps to the warm boot address as the cold boot is already done by then.
There doesn't have to be anything more than a formatted black floppy in
the drive (CCP logs the current drive, so something has to be there).

Thats an example of what the book doesn't tell you.

Allison
Received on Thu May 27 1999 - 15:27:38 BST