Improving 360 Addressing
On Fri, 14 Jul 2006 06:09:23 GMT in alt.folklore.computers,
module CSECT STM R14,R12,12(R13) save regs LR R12,R15 set base to entry USING module,R12 rel base reg * either prev 2 or next 2 BALR R12,0 set base here USING *,R12 pic base reg ... do work DMSFREE DWORDS=18-2,ERR=nomem new reg save area XC 0(18*4,R1),0(R1) clear reg save area ST R13,4(R1) save prev ptr in curr area ST R1,8(R13) save curr ptr in prev area LR R13,R1 use curr save area LA R15,0 set return code ... do work L R15,=A(routine) callee BALR R14,R15 call ... do work LR R1,R13 save curr save area ptr L R13,4(R13) rest prev save area ptr XC 0(18*4,R1),0(R1) clear old reg save area DMSFRET DWORDS=18-2,LOC=(R1) ret old reg save area ST R15,16(R13) set return code in prev save area LM R14,R12,12(R13) rest regs from prev save area BR R14 return
LTORG
lowest-numbered register
datacell was direct access .... i.e. applications selected records on strip (using BBHHCCR convention) and directly read-wrote the records. 3850(-MSS) were virtualized 3330 disk drives...
R11 module (addl) base address (if reqd) R12 module (main) base address R13 reg save area ptr from caller R14 return addr R15 entry addr-return code
-- Thanks. Take care, Brian Inglis Calgary, Alberta, Canada
Magnetic drums tend to be used either for computer memory, or swap space. Of course, a drum...
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