* CS/80 bootrom transcribed from 12992J listing
* SR bits 0-2 = unit
* SR 6-11 normally set to select code but not necessary (I think..)
      ORG 77700B
IBI   EQU 21B
START LIA 1          GET SWITCH REGISTER
      AND XXX        AND OUT UNIT
      IOR UNIT       PUT IN UNIT COMMAND
      STA UNIT       SAVE FOR BUS
      CLE
*
* WAIT FOR DRIVE 0 READY
*
      JSB BTCTL      SEND UDC,PPOL
      LIA IBI        READ INPUT REGISTER
*     ASR 7          SHIFT DRIVE RESPONSE TO LSB
      OCT 101027     assembler doesn't support ASR 7
*     SLA,RSS        DID DRIVE 0 RESPOND
      OCT 002011     avoid bugs
      JMP *-3        NO GO WAIT
*
      CLC 0,C        SHUT DOWN EVERYTHING ELSE
      JSB BTCTL      SEND TALK,READ,BUS HOLDER
      CCE
      JSB BTCTL      TELL CARD TO LISTEN
*
* PERFORM DMA TRANSFER
*
      LDA DMACW      LOAD DMA CONTROL WORD
      OTA 6          OUTPUT TO DCPC
      CLC 2          READY DCPC
      LDA ADDR1      LOAD DMA BUFFER ADDRESS
      OTA 2          OUTPUT TO DCPC
      LDA DMAWC      LOAD DMA WORD COUNT
      STC 2          READY DCPC
      OTA 2          OUTPUT TO DCPC
      STC 6,C        START DCPC
TEST  SFC 6          SKIP IF DMA NOT DONE
      JSB ADDR2,I    SUCCESSFUL END OF TRANSFER
      SFS IBI        SKIP IF DISC ABORTED TRANSFER
      JMP TEST       WAIT...WAIT...WAIT
ADDR1 HLT 11B        ERROR HALT (also load address 2011)
*
* PROGRAM CONSTANT TABLE
*
UNCLR OCT 677        UNLISTEN
      OCT 737        UNTALK
DMAWC OCT 176624     UNIVERSAL CLEAR,LBO/DMA WORD COUNT
      OCT 624        SECOND UNIVERSAL CLEAR
LIST  OCT 440        LISTEN BUS ADDRESS 0
CMSEC OCT 745        COMMAND MESSAGE
UNIT  OCT 40         UNIT
READ  OCT 1000       READ
UNLST OCT 677        UNLISTEN
TALK  OCT 500        DEVICE TALK
EXEC  OCT 100556     EXECUTION MESSAGE
ADDR2 OCT 102055     BOOT EXTENSION STARTING ADDRESS
CTLP  OCT 4003       INT=LBO,T,CIC
XXX   OCT 47         PPE,L,T,CIC
      OCT 4003       INT=LBO,T,CIC
      OCT 413        ATN,P,L,CIC
      OCT 1015       INT=EOI,P,L,CIC
      NOP
*
*
*
BTCTL NOP
      CLC IBI,C      RESET IBI
BM    LDA CTLP       LOAD CONTROL WORD
      OTA IBI        OUTPUT TO IBI
      STC IBI        RETURN IBI TO DATA MODE
      ISZ BM         INCREMENT CONTROL WORD POINTER
      SEZ,CME
      JMP BTCTL,I    RETURN
LABL  LDA UNCLR      LOAD DATA WORD
      ISZ LABL       INCREMENT WORD POINTER
      OTA IBI        OUTPUT TO HPIB
      SSA,RSS        SKIP IF LAST WORD
      JMP LABL       GO BACK FOR NEXT WORD
      SFS IBI        SKIP IF LAST WORD SENT TO BUS
      JMP *-1        WAIT FOR ACCEPTANCE
      JMP BTCTL+1
DMACW ABS IBI
      ABS -START
      END