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2. Features of UT62 Monitor Program
The purpose of the monitor program is to provide a
convenient place for the microprocessor to begin
running. The monitor allows the user to start BASIC3,
the editor, the assembler, or a user-generated program
at any address.
While the microprocessor is running in the UT62
monitor, several memory functions are available
through the data terminal. On a byte or block basis,
memory can be displayed, modified, or moved. Also,
the microprocessor register values on entry into the
monitor program can be examined by displaying
memory at location 8C00H. This REGISTER SAVE
feature can be used to debug machine language
programs by inserting an IDLE instruction (00) in the
user’s code at the appropriate place and then running
the monitor program by means of the RESET/RUN
switch. All registers are saved in memory at 8C00EI
except the values of R0, R 1, and R4.1 which are lost in
the process.
The monitor can also load and save programs on the
cassette tape units and display ASCII files from tape
on to the terminal. The tape SAVE routine can store 1
byte or any contiguous block of bytes from any space
in memory. The tape LOADER will restore any saved
memory and can also load tapes created by the Level 1
assembler of the CDP18S694.
To start running the monitor program, the user
should place the RESET/RUN switch in the reset
position and then move it back to the run position. The
user should then press the carriage return key (CR) on
the terminal. The * prompt signifies that the system has
calculated the baud rate of the terminal and is now
ready to accept monitor commands.
UT62 Commands
preceded by a space or an inclusive
address range preceded by a hyphen. If
the option is not specified, a default
value of 1 byte results.
Examples:
D02F8 8(CR)
D02F8-02FF(CR)
Both of these examples produce the
same output.
I Commands
Name:
Purpose:
Format:
Action:
Examples:
Memory Insert
To alter the contents of memory
beginning at the specified address.
I (START ADDR)(SPACE)
(DATA)[(CONT)](CR)
A memory location is accessed at the
specified (START ADDR). The(DATA)
required is one byte specified by two hex
digits. The (CONT) option allows data
to be continued changing the current
memory address. If a (SEMICOLON) is
entered and after a user-inserted
(CR)(LF), a new address is anticipated.
The semicolon allows non-contiguous
memory to be loaded with a single insert
com m and. The com m and may be
terminated at any point by the entry of a
(CR) or (SEMICOLON).
I02F8 7100F840B0F88CB1(CR)
I02F8 7100F840B0;(CR)(LF)
03B6 94FB903A0F(CR)
The second example enters data into
two memory areas, starting at 02F8 and
03B6.
M Commands
Following is a description of the thirteen UT62
commands. Note that all address, data, and byte
counts are entered as hexadecimal numbers (indicated
by the letter H following the number). In these
examples, the characters generated by the system are
underlined.
D Commands
Name:
Memory Display
Purpose:
To allow a specified area of memory to
be displayed on the user terminal.
Format:
D(START ADDR)(OPTION)(CR)
Action:
The contents of memory, beginning at
the specified (START ADDR) will be
transm itted to the user term inal.
(OPTION) allows the transmission of
either a specific num ber of bytes
Name:
Purpose:
Format:
Action:
Examples:
Memory Move
To move a block of data from one area
of memory to another area.
M(SOURCE ADDR)(OPTION)(SPACE)
(DEST ADDR)(CR)
Data is copied from memory location
beginning at the (SOURCE ADDR)
into locations specified by the (DEST
ADDR). (OPTION) allows the transfer
of either a specific number of bytes
preceded by a space or an inclusive
address range preceded by a hyphen.
There is no restriction on the direction
of the move and the areas may overlap.
M02F8 8 03F8(CR)
M02F8-02FF 03F8(CR)
