488 CONTROLLER
64
REMOTE Command
The REMOTE command asserts the Remote Enable (REN) bus management line. If the optional bus
addresses are specified, then REMOTE also addresses those devices to listen, placing them in the Remote
addressed state.
SYNTAX
REMOTE or REM
RESPONSE
None
MODE
SC
BUS STATES
REN
EXAMPLES:
PRINT #1,"REMOTE"
Assert Remote Enable
SYNTAX
REMOTE addr[,addr] or REM addr [,addr]
addr
is a bus device address
RESPONSE
None
MODE
SCCA
BUS STATES
REN, ATNUNL, MTA, LAG
PRINT #1,"REMOTE16,28" Assert Remote Enable and address devices 16 and 28 to listen.
REQUEST Command
In Peripheral mode, the 488 Controller is able to request service from the Active Controller by asserting the
Service Request bus signal. The REQUEST command sets the Serial Poll status (including Service Request)
of the 488 Controller. REQUEST takes a numeric argument in the range of 0 to 255 (&H0 to &HFF) that is
used to set the Serial Poll status. When the 488 Controller is Serial Polled by the Controller, it returns this
byte on the DIO data lines.
The data lines are numbered DIO8 through DIO1. DIO8 is the most and corresponds to a value of 128
(&H80). DIO7 is the next most significant line and corresponds to a value of 64 (&H40). DIO7 has a special
meaning: It is the Request For Service (rsv) bit. REQUEST always forces this bit to a “1” which generates a
service request (SRQ) to the controller.
When the 488 Controller is Serial Polled, all eight bits of the Serial Poll status are returned to the Controller.
The rsv bit is cleared when the 488 Controller is Serial Polled by the Controller. This causes the 488
Controller to stop asserting SRQ.
SYNTAX
REQUEST [;][status] or REQ [;][status]
status
is the service request status in the range of 0 to 255. If
status
is not specified,
only rsv (DIO7) is asserted.
RESPONSE
None
MODE
*CA
