On-line Debugging Tool: Difference between revisions

Revision as of 22:18, 20 April 2014

Revision as of 01:34, 21 May 2014

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'''On-line Debugging Tool''', or ('''ODT''',) was theused nameto ofdescribe several [[debugger]] programs originally developed for [[Digital Equipment Corporation|DEC]] (DEC) hardware. Various [[operating system]]s including [[OS/8]], [[RT-11]], [[RSX-11]], and [[RSTS/E]] implemented ODT as did the [[firmware]] console of all of the [[LSI-11]]-family processors including the 11/03, 11/23/24, 11/53, [[PDP-11/73|11/73]], and 11/83/84.

The debugger allowed access to memory using [[octal]] addresses and data. Within the [[software system]]s, the debugger accessed the process's [[virtual memory]]. The firmware console implementation accessed [[physical memory]].

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==Console ODT==

Console ODT<ref>p192-202 ''PDP-11 Processor Handbook: pdp11/04/24/34a/44/70'', Digital, 1981</ref> replaced the lights and switches console of many of the earlier processors.

Access to console ODT is obtained either from power up (with appropriate power up mode selected), by the execution of a HALT instruction in kernel mode, or by use of the front panel halt switch or button.

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The underscore is the standard ODT prompt.

It should be remembered that addresses in the ODT debugger are 16 bit virtual addresses in the mode in which ODT is currently operating, not the physical addresses used with console ODT.

===Commands===

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|-

| .

| Current ___location indicator, i.e., address of last ___location opened

|-

| <CR> or k<CR>

| Closes current ___location/register. If k is specified stores the value k in the currently open ___location before closing it.

|-

| <LF> or k<LF>

| Closes current ___location/register and opens next If k is specified stores the value k in the currently ,open ___location before closing it.

|-

|^ or k^

| Closes currently ,open ___location and opens immediately preceding. If k is specified stores the value k in the currently open ___location before closing it.

|-

| _ or k_

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|-

| > or k>

| Treats the low order byte of the currently open ___location as a branch offset, calculates the destination address of the branch and opens that ___location. If k specified stores the value k in the currently open ___location before opening the new ___location

|-

| < or k<

| If the currently opened ___location was opened using the commands _ or > or @ closes the currently open ___location and reopens the ___location most recently opened using <lf>, ^, or /.

|-

| $n

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|-

| " or a"

| Word mode [[ASCII]] Displays contents of the ___location a or the currently open ___location as [[ASCII]] and stores the contents of this ___location to $Q register.

|-

| ' or a'

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|-

| % or a%

| [[DEC Radix-50|Radix50]] operator. Displays the contents of the ___location a or the currently open ___location as RADIX 50 and stores the contents of this ___location to $Q register.

|-

| / or a/

| Word mode octal operator. operator. Displays the contents of the ___location a or the currently open ___location as [[octal]] and stores the contents of this ___location to $Q register.

| \ or a\

| Byte mode octal operator. operator. Displays the contents of the ___location a or the currently open ___location as [[octal]] and stores the contents of this ___location to $Q register.

|-

| k=