Advanced
programming
Side 2 of your system discs package contains a number of programs intended
for
use
by advanced and system programmers.
It
is recommended
that
the user consult
SOFT 971-A Guide to
CP/M
Plus, or other reference works.
Working
with
CP/M
2.2
This section is intended to highlight
the
differences when operating using
CP/M
2.2.
CP/M
2.2 is loaded from
the
first two tracks of a System disc. The bootstrap sector is
different from
that
used to load
CP/M
Plus and care should be
taken
not to confuse
them. Although
it
is possible to use Vendor, IBM, and
Data
format discs
in
either disc
drive, operational considerations usually restrict
their
use to
the
second disc drive.
Unless special action is
taken
by
the
CPIM
program (as F I LEe 0
PY
does
for
example)
then
CPIM
2.2 will not allow you to write to a disc unless
it
has been 'logged
in'. Furthermore,
the
type of disc format (System, Data, or
IBM)
is only
re-determined when a disc is logged in. For the
main
disc drive within
the
computer
(Drive
A)
this takes place whenever
CP/M
2.2
returns
to the Direct Console Mode, or
when
[CONTROl]C is typed
at
the
A>
or
B>
prompt. For
an
additional drive (Drive
B)
this
takes place
the
first time
that
the
disc
in
Drive B is accessed, after Drive A has
been logged in.
Should you
try
writing to a disc
that
has
not been logged in, the infamous error
message:
Bdos
Err
on
,drive>:
RIO
.... will be displayed. Press any key to continue.
If
the changed disc was also of a
different format
then
a read or write error will occur. Type C to continue.
If
you receive software on a disc in Vendor format,
then
in order to use
it
conveniently, you may
either
copy
it
to a
CPIM
2.2 system disc by using F I LEe 0 P Y
or
PIP,
or alternatively convert
the
disc to a system disc by adding your
CP/M
to it.
This is achei ved with
the
BOO
T G E
Nand
S Y S G E N commands. Carefully read the
End
User Licence Agreement
in
this
manual
(Appendix
1).
S Y S G E N (with no parameters) is a specialised copier program which prompts
for
a
source and destination disc, and copies the
CP/M
2.2 system tracks from one disc to
another.
BOO
T G E N similarly copies Sector
1,
track 0 (the loader) and the
configuration sector from one disc onto another.
The
D I R command does not accept parameters (other
than
a file specifier). The
filenames
are
not sorted into any particular order,
but
the
po
si tion of
the
filename in
the
D I R display indicates
the
position of
that
file's entry in the disc directory.
AMSDOS
and
CPIM
Chapter 5 Page
33
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