TOPS-20 Commands Reference Manual

EXAMINE

Displays the contents of a memory location.

Format

@EXAMINE (MEMORY LOCATION) octal or symbolic address

Output

Contents of Memory Location or Message

When you complete an EXAMINE command, the system prints the memory address examined, followed by a slash (/) and its contents. If you previously used the SET TYPEOUT MODE SYMBOLIC command, this information is both in symbolic and, in parentheses, numeric (octal) format. (The numeric information will always appear for this setting of the command; symbolic information will appear if the system finds that it is different from the numeric.)

Generally the numeric format shows two 6-digit octal numbers separated by a pair of commas (,,). If you do not see this pair of commas, only the right half of the memory location is being displayed; as the left half is 0. However, if you are not permitted to examine this location, the system prints only a message telling you of the restriction.

Hints

Using Symbols

For symbols that are defined in multiple modules of a program, you can be specific by giving the module name followed by an ampersand (&) and the symbol name.

Abbreviating EXAMINE

The EXAMINE command can be abbreviated by the single letter E.

Default Argument for EXAMINE

The argument of your current EXAMINE command defaults to a value greater by 1 than the last address examined, allowing you to inspect a section of memory with only a minimum of typing. But if you gave a more recent DEPOSIT command, the argument of your current EXAMINE command defaults to that address, allowing you to verify the deposit.

Using EXAMINE With Noncurrent and Inferior Forks

The EXAMINE command displays memory locations of the current fork. To examine the memory of noncurrent or inferior forks, make the fork the current fork by giving the FORK command with the fork name or number as an argument.

To run an inferior fork after examining it, you must ensure that all superior forks are running too. Give the CONTINUE command with the superior fork name or number as an argument to let the superior fork continue its inferiors.

Related Commands

DDT for calling a debugging program, allowing more efficient examination of memory
DEPOSIT for changing the contents of a specific memory location
FORK for selecting the fork whose memory you want to examine
INFORMATION MEMORY-USAGE for displaying a list of memory pages, their contents and status
SET TYPEOUT MODE for displaying information in symbolic or numeric format

Examples

  1. Examine location 550 of the current fork. 
    @EXAMINE 550
550/    74473,,414155
  2. Examine location 20, first in numeric typeout mode, then in the symbolic mode. 
    @SET TYPEOUT MODE NUMERIC
@EXAMINE 20
20/ 104000,,56

@SET TYPEOUT MODE SYMBOLIC
@EXAMINE 20
P+1/ 104000,,.JBBLT+11   (20/ 104000,,56)
  3. Put a program into memory and find out what pages it occupies. Examine a location on page 2, and then (using the abbreviated form of the EXAMINE command) one on page 400. 
    @GET DMN
@INFORMATION MEMORY-USAGE

 5. pages, Entry vector loc 400010 len 254000

  Section 0    R, W, E,  Private
0-3           DMN.EXE.1  1-4   R, CW, E
 400          DMN.EXE.1  5   R, CW, E

@EXAMINE 2550
2550/   600170
@E 400550
400550/ 0