B Jumper Block Reference; Jumper Block Js (Data - Adaptec AHA-1520 User Manual

AppendixB Jumper Block Reference
The following sections describe the functions of each of the jumper pins on each
of the jumper blocks on the host adapter board. In each section, a diagram of the
default jumper settings is followed by a description of the function of each pin
pair. The pin pairs are referred to by the two-character codes printed next to
them on the host adapter board.
JUMPER BLOCKJ5 (DATA)
Jumper block JS controls a number of different options on the host adapter. The
following diagram shows the default settings of jumper block JS:
Pin Pair
Pin Pair OT
Pin Pair BT
Pin Pairs
MO, Ml
Description
You use this pin pair
to choose whether data transfer will be
performed in PIO or OMA mode. H no jumper is installed (the
default), data transfer is performed in the PIO mode. If a jumper
is installed, data transfer is performed using second-party DMA.
You use this pin
pair to choose whether the host adapter BIOS
intercepts the INT19 call and performs the boot operation. Ha
jumper is installed (the default) the BIOS intercepts INT19 and
performs the boot operation. If no jumper is installed, the BIOS
does not intercept the INT19 call.
You use these pin pairs to select which types of messages you
want the AHA-1S20/1S22
to display when you boot your
computer. The AHA-1S20/1S22 can display five different
classes of message:
0-Adaptec header display
1-Jumper configuration information
2-SCSI device information
3-Boot progress report
4-Error messages
AHA-1520/1522
B-1
adaptec