srec_hp64k - Man Page

HP64000 Absolute Data Format

Description

This format is the output of the HP 64000 Development System Linker and associated tools. All fields are 16-bit words. This is a binary (non-text) file format.

File Format

Files in this format start with a header record.

Then comes the Processor Information Record.

Then comes the data itself, organized into records.

Overall Structure

Magic
Number
0x8204		Processor
Information
Record(PIR)		Data
Record #1

------
Data
Record #N
(N <=127)

Header

The header consists of 8 words which are interpreted as a null terminated string:

Data
Word
1		------

Data
Word
8

Processor Information Record (PIR)

The PIR does not have a checksum; it is therefore possible that a corrupt file header will go undetected.

Data
Bus
Width		Data
Width
Base		Transfer
Address
LS Word		Transfer
Address
MS Word

Data Record

Each data record consists of a byte count followed by the comensurate number of words. The data part of each record is raw byte values, no encoding.

Number
of
Bytes		Load
Address
LS Word		Load
Address
MS Word		Data
Word
1		------
Data
Word
N Data

The checksum is calculated by a simple sum of unsigned bytes into a 32-bit accumulator.

Commentary

The implementation is based on two documents:

  • HP 64000 Logic Development System - File Format Reference Manual , #64980-90933, 1985
  • HP 64700 Operating Environment - Absolute File Translator. HP Part No. B1471-97008, 1992

These documents disagree on some points, and also do not quite match actual examples (firmware update files from early 90's equipment; probably generated from an unknown MC68k toolchain).

The main points of disagreement are:

  • Two first bytes of the file, before any header or the "Processor Information Record", are not officially documented anywhere yet found. (68k linker docs may be worth investigating if they can be found). In this implementation they are set to "82 04", where 04 matches HP doc's "type" value of 4 for Absolute files.
  • Header: Only mentioned in B1471. 16 bytes of user data? Present in this implementation.
  • "recsize" (author's terminology) : redundant field, before every record, giving length of its record minus 1, i.e. recsize == (DataRecord.numbytes + 6) - 1

Source

HP 64000 Logic Development System - File Format Reference Manual, #64980-90933, 1985 https://archive.org/details/bitsavers_hp64000sof986_8480556

HP 64700 Operating Environment - Absolute File Translator. HP Part No. B1471-97008, 1992 https://archive.org/details/bitsavers_hp64700sof008AbsoluteFileTranslatorMar92_143924

Maintainer

Scott FinneranE-Mail:scottfinneran@yahoo.com.au
Peter MillerE-Mail:pmiller@opensource.org.au

Info

SRecord Reference Manual