Reading Level Ii Codes - Pioneer LD-V8000 User Manual

3.2.2 Reading Level II Codes

Program codes can be read from the player's memory by an external computer in a
manner similar to that used to send them to the player.
First, set the memory location pointer with the *S command just as you would for
sending code to the player. The location specified will be the first code byte read.
Second, use the *D command to tell the player now many code bytes to transmit
from it's memory. The maximum transmission is 64 bytes of code, followed by a
carriage return. Each byte is sent as two Hex characters, so a maximum of 128
characters are transmitted.
To aid reading sequential sections of the player's memory, the memory location
pointer is increased by one every time a byte of data is output.
Example: Read the first 9 bytes of the program downloaded in the previous section.
• Set the memory location pointer.
As before, set the memory location pointer to 120:
> 120*S<CR>
<
• Transfer Data.
Ask the player to transmit 9 bytes of code:
> 9*D<CR>
< 0F3F3F3FF70F8F3F3F<CR>
The memory location pointer will be at 129 when the player's transmission is
complete.
At this point the programmer should note that the player's Program Address
Pointer is used for two different purposes:
First, it is used during the execution of a Level II program to indicate the
instruction being processed. While being used in this manner, the Program
Address counter will point to a location in active memory.
Second, it is set by the *S command and is used as a Memory Location Pointer by
the Level III downloading and code reading commands. At this time, it may point
to any of the byte locations (addresses) in memory, even if only one page is active.
Pioneer LD-V8000 Level II User's Manual
LD-V8000 Level II • Chapter Three
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TP 114 v. 1.1 • 8/92
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