Radio Shack TRS-80 CR-510, Руководство по эксплуатации

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08
Erase Previous Character
The Hexadecimal value 08 (ASCII BS) will cause the previous character sent to the CR-510 to be
erased. If it is the first character in a command string, it will be treated as a no-op.
Status
The following table lists the status conditions that can be returned to the computer if status is enabled
(ST1) or an STA command is sent.
Card Reader Status
* The echo error status will reset once status has been sent to the TRS-80 and an RTX or PIK
command is received.
** Indicates one of the following:
• Unit START button was not pressed.
• The Card Reader is currently performing the Self-Test or Diagnostic Self-Test.
• Unit STOP button was pressed.
*** An invalid command string was received. Requesting status and sending a valid command
string will clear the error condition. RES or a hard reset will also clear the error.
For information on how to prevent and remedy feed errors, refer to Adjusting the CR-510's Feed.
CR-510 Communications Overview
The following section provides an overview of potential communications problems and their solutions.
Command Errors
The CR-510 provides status, when requested, and in most instances will return a reverse slash if valid
data cannot be transmitted to the computer.
For example, suppose the CR-510 received the following command strings issued from a computer
program:
ASC LFO STO ECO DFD PIK PIK (Carriage Return)
HX3 PIK (Carriage Return)
PIK (Carriage Return)
In this hypothetical situation, there are three cards in the hopper. When the START/STOP button is
pressed, the first command string will place the Card Reader in the demand feed mode (ASCII
format), line feed off, with status and echo disabled. Next, it will read the first card and transmit the