LDA-11(5) Retro Project Manual LDA-11(5) NNAAMMEE lda-11 - absolute loader paper tape format DDEESSCCRRIIPPTTIIOONN llddaa--1111 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 xxxxddpp system. DEC RT-11 and RSX tools also supported this file format. An llddaa--1111 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 NNOOTTEESS llddaa--1111 files can be created with aassmm--1111, inspected with llddaadduummpp, and loaded into a system with ttii__ww1111. SSEEEE AALLSSOO aassmm--1111(1), llddaadduummpp(1), ttii__ww1111(1) AAUUTTHHOORR Walter F.J. Mueller Retro Project 2022-05-13 LDA-11(5)