Base Configuration; Status Word - HP 98780 CE Handbook

Base Configuration
98780 Configuration
3-1
Chapter
3
Configuration
The following assemblies must be installed in the 9845B base to support the 98780A. (These
parts are included in the 98404A Upgrade Kit.)
98780-65501
1818-1591
and 1818-1592
98770-66534
Enhanced Graphics ROM
Mainframe ROM for Enhanced Graphics ROM
Mainframe ROM for Enhanced Graphics ROM
Alpha Control Assembly (Replaces 09845-66503 in base.)
Refer to the 9845B Base CE Handbook Chapter for the locations of these parts.
Interfacing
The 98780A interfaces to the 9845B base via the Alpha Control Assembly (98770-66534) and
the Graphics Interface Assembly (09845-66504). Alpha information is stored in block 0 read-
write memory, and is refreshed to the display via the IDA bus. Graphics information is transfer-
red via the I/O bus to the display, where it is interpreted and entered into the display memory.
Status Word
The Status Word may be obtained by executing the following instructions:
STATUS 13;A
DISPA
The result is a decimal integer which may be converted to binary and interpreted as shown
below.
Bit
Bit Description
13 Graphics status
11,9 Identification bits
7 Interrupt enable
6 DMA enable
3 Option service request
2 Graphics service request
1 Softkey service request
o
Light pen service request
I