w11 - /man/cat5/lda-11.0

LDA-11(5)                    Retro Project Manual                    LDA-11(5)


NAME
       lda-11 - absolute loader paper tape format

DESCRIPTION
       lda-11 files contain an absolute binary executable for a PDP-11 system.
       They were initially defined for usage with paper tapes, see
         Paper Tape Software Programming Handbook  DEC-11-OOPB-D     Mar 1971
         Paper Tape Software Handbook              DEC-11-XPTSA-B-D  Apr 1976
       and later used in the disk-based xxdp system. DEC RT-11 and  RSX  tools
       also supported this file format.

       An lda-11 file contains one or more blocks of the format

           0 001    start frame
           1 000    null frame
           2 xxx    byte count low
           3 xxx    byte count hight
           4 yyy    load address low
           5 yyy    load address high
             ...    data
             zzz    block checksum

       and the properties
       - the byte count is the total number of bytes in a block, excluding the
         checksum but including the 6 header frames.
       - the checksum is the 2-complement of the sum of the whole  block,  in-
         cluding the 6 byte header
       - if the byte count is 6:
         - if  the  load  address is even, the loader will transfer control to
           that address
         - if the load address is odd, the loader stops the CPU with a HALT

NOTES
       lda-11 files can be created with asm-11, inspected  with  ldadump,  and
       loaded into a system with ti_w11.

SEE ALSO
       asm-11(1), ldadump(1), ti_w11(1)

AUTHOR
       Walter F.J. Mueller <W.F.J.Mueller@gsi.de>


Retro Project                     2022-05-13                         LDA-11(5)