using the bootstrap loader
using the bootstrap loader
using the bootstrap loader
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WRITING A CUSTOM FIRST-STAGE DRIVER<br />
5-28<br />
/************************************************************<br />
* This example reads <strong>the</strong> general purpose register of <strong>the</strong> *<br />
* unit definition record within <strong>the</strong> interconnect space *<br />
* found on <strong>the</strong> board in slot number three. Note that *<br />
* this code does no checking of status after each call to *<br />
* BS$GET$INTERCONNECT. The programmer must ensure <strong>the</strong> *<br />
* value returned is correct. *<br />
************************************************************/<br />
SAMPLE_BS$GET$INTERCONNECT: DO;<br />
DECLARE slot$number BYTE;<br />
DECLARE record$offset WORD;<br />
DECLARE unit$def$rec BYTE;<br />
DECLARE rec$length$reg$off BYTE;<br />
DECLARE gen$status$reg$off BYTE;<br />
DECLARE record$found BYTE;<br />
DECLARE eot$rec BYTE;<br />
DECLARE status WORD;<br />
DECLARE value BYTE;<br />
DECLARE slot LITERALLY '3R';<br />
DECLARE udr LITERALLY 'OFER';<br />
DECLARE gsro LITERALLY 'OAH' ;<br />
DECLARE eotrec LITERALLY , OFFH' ;<br />
DECLARE rlro LITERALLY 'OIR';<br />
DECLARE ro LITERALLY '020H';<br />
CODE: DO;<br />
slot$number<br />
unit$def$rec<br />
gen$status$reg$off =<br />
eot$rec<br />
rec$length$reg$off =<br />
slot;<br />
udr;<br />
gsro;<br />
eotrec;<br />
rlro;<br />
/***********************************************************<br />
* Set up to read <strong>the</strong> first nonheader record within <strong>the</strong> *<br />
* interconnect space. This is done by establishing *<br />
* record$offset past <strong>the</strong> interconnect space header *<br />
* record, which in this case is 32 bytes long. *<br />
***********************************************************/<br />
record$offset = ro;<br />
Bootstrap Loader<br />
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