27 May
1999
27 May
'99
8:12 a.m.
Still that doesn't explain the 7680 bytes in the
file from
the site. I still don't know what to do.
Well, 7680 bytes = 60 128-byte sectors, which is more than the first
two tracks on an 8" floppy. I suspect that the "file on the site"
is from an implementation where the boot track was double density
or on something other than an 8" floppy. (30 256-byte sectors,
15 per track, maybe? Sounds like a 5.25" DD format.)
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.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
27 May
27 May
8:27 a.m.
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
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