Loading And Initialization Procedures For The Text Editor; Starting Execution - Texas Instruments 990 Operation Manual

J2n,.5\ _ _ _ _ _ _ _ _ _ _ _ _
~
945255-9701
In an 8K system with 4K user memory, PX9EDT contains 3870 bytes of edit buffer space. Lines
are placed in the buffer with one character per byte followed by a carriage return, and preceded
by a six-byte header. Therefore, a buffer of lines with an average length of 40 bytes, including
header and carriage return, would contain approximately 100 lines. Using tabs when inputting
source lines causes a tab to be placed in the buffer instead of multiple spaces.
4.3 LOADING AND INITIALIZATION PROCEDURES FOR THE TEXT EDITOR
The following paragraphs describe the loading procedure and the messages output during
initialization and termination.
4.3.1 LOADING. PX9EDT is loaded by means of the PX9MTP Load Program in Compressed
Absolute Format with Up front Loader (LU) command. Mount and position the cassette contain-
ing the PX9EDT object code and enter this command on the terminal keyboard:
LU
The LU command assumes that the cassette is mounted in the cassette drive assigned to logical
unit number 7. Be sure that logical unit number 7 has not been reassigned to another device.
Other acceptable load program commands are the following:
LU,7 Load program with upfront loader from LUNO 7
LU,8 Load program with upfront loader from LUNO 8
4.3.2 STARTING EXECUTION. The user then uses the PX9MTP Execute User Program
Directly (EX) command to begin execution of PX9EDT. PX9EDT accepts input from logical unit
number 7 and writes its output to logical unit number 8. To use other than system defaults, the
PX9MTP Assign LUNO (AL) command should be used before the EX command is ent.ered.
(Refer to the discussion of logical unit numbers in Section II and the discussion of the AL
command in Section III.)
4.3.3 INITIALIZATION MESSAGES. When PX9EDT is started, it prints a series of messages
requesting user responses. The first two messages are printed the first, time PX9EDT is executed
after being loaded. In subsequent executions and restarting PX9EDT, the first two messages will
be deleted.
This message identifies the program name and release information:
PX9EDT PART
#
REV DATE
The following message asks for a count of memory blocks:
ADD 4K MEM BLOCKS CONFIGURED?
The user should input the number of 4K user memory blocks that are configured in his system
in addition to the 4K required by PX9EDT. This additional memory will expand PX9EDT's edit
buffer space. For example, if the user's system contains 8K of user memory in addition to the
4K required by the monitor, the response should be "1". If the user's system contains 4K of
user memory, the response should be "0" or a carriage return.
If the configuration includes more than 4K words of user memory area, PX9MTP will be
relocated as described in the system software cassette generation procedure in Section II.
4-2
Digital Systems Division