User`s guide

Page 23
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where d identifies the drive selected when the error condition
is detected; error message identifies the error; nn is the BDOS
function number, and filemane.typ identifies the file specified
by the BDOS function. If the BDOS function did not involve an
FCB, the file information is omitted. Note that the second line
above the error message is displayed only in the banked
version of CP/M 3 if expanded error message reporting is
requested by GENCPM (p. 2-29)”.
O.k., so from this I know the error message means that BDOS (I
found out this acronym stands for Basic Disk Operating
System) is telling me that there is some type of disk error on
drive B. The BDOS function number (14 in this case) is defined
as “Select Disk”. I guess I should have had a disk in the drive
and the latch closed! It seems to me that CP/M will check the
drive for a disk when an attempt is made to switch from the
default drive (or any other drive) which had been placed into
the primary position (as indicated by the prompt). I’ll put BDOS
down on my list of things to get more information on.
So if I summarize what I have researched so far, here is one
way of how I do it...
CP/M (Control Program for Microprocessors) is a system of
organizing information via hardware and software. When
booting the system on a 40 column screen the computer
displays information on the CP/M version number followed by
printing “On Commodore 128", the date, current user number
(0 being the default and is not shown) followed by the current
default drive letter and the status of the disk drive. The user
number and the default drive letter are followed by the right
bracket “>” and is known as the system prompt. This is where
the user enters information called a command. This could be a
system command or a call to a program. CP/M handles
interfacing with disk drives via BDOS (Basic Disk Operating
System).
CP/M on the Commodore 128 includes the following :
There is 59 kilobytes of Transient Program Area (user RAM)
A maximum of 4 disk drives can be connected (512 Megabytes
maximum capacity)
CP/M will recognize a RAM expansion unit (set to drive M)
Recognizes a virtual drive (E)
Can use a 40 or 80 column display.
Other peripheral devices can be connected.
End of Part 2
Commodoreman
CHECKLIST
Hard drive (note: logical drive capacity cannot exceed 512 MB –
CP/M Programmer’s Guide, sec. 1.5, p. 1.11). Find out more
about this feature (can I still get one?)
REU CP/M disk
BDOS
What is the date displayed on startup? Is it the date of the OS
or is it there to represent the current date? If so how do I
change it?
How do I use other peripheral devices (modem, printer,
joystick, etc.)?
What other high-level languages exist (BASIC, FORTRAN, COBOL,
etc.)?
LIST OF RESOURCES
Hardware:
Commodore 128D/1571
1541
1581
1750 REU
1702 Monitor
1902 Monitor
Software:
CP/M System Boot Disk
Genealogy Program
other CP/M formatted disks (copies of system disk)
Printed Material:
Commodore 128D User’s Guide
Commodore 128 Programmer’s Reference Manual
Digital Research User’s Guide (3 books in one)
Commodore 128 CP/M User’s Guide - ABACUS
ISBN#0916439453
Other:
Internet