srec_dec_binary(5)

💖 NAME 💖

Meet srec_dec_binary(5), bestie — the DEC Binary (XXDP) file format page from the File Formats Manual. This was used on the PDP 11 series machines, and it’s giving old-school binary realness. ✨

🎀 DESCRIPTION 🎀

So the DEC Binary (XXDP) format was used on the PDP 11 series machines. This is a binary format, and it is not readable or editable with a text editor — do not try to open it in a text editor and expect cute little lines of text, okay? 😭

The file consists of records of the form:

┌──────┬────────┬─────────┬────────────┬──────────┐
│ type │ length │ address │ ...data... │ checksum │
└──────┴────────┴─────────┴────────────┴──────────┘

The fields are defined as follows:

• type — two byte little-endian value. Must always be 1. No cap, it just has to be 1.
• length — two byte little-endian value. This is the number of bytes in the data, plus 6.
• address — two byte little-endian value. This is the load address of the data.
• data — the data is simple raw bytes. There are (length-6) of them.
• checksum — the checksum is a single byte. It is the negative of the simple sum of all the header and data bytes.

If the record length is exactly 6 (i.e. no data), this is the execution start address record, indicating the transfer address. 👑

In addition there may be NUL padding characters between records. It is common for records to be padded so that they start on even byte boundaries. In the days of paper tape, it was common for the file to have many leading NULs, to generate blank leader on the tape. 🎞️

📏 Size Multiplier 📏

In general, raw binary data will expand in size by approximately 1.03 times when represented with this format. Tiny glow-up, honestly. 💅

📜 COPYRIGHT 📜

srec_cat version 1.65 Copyright (C) 1998... Peter Miller

The srec_cat program comes with ABSOLUTELY NO WARRANTY; for details use the 'srec_cat -VERSion License' command. This is free software and you are welcome to redistribute it under certain conditions; for details use the 'srec_cat -VERSion License' command. 🫶

🌈 MAINTAINER 🌈

• Scott Finneran — E-Mail: scottfinneran@yahoo.com.au
• Peter Miller — E-Mail: pmiller@opensource.org.au

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✨ kisses from the Reference Manual / SRecord crew, page srec_dec_binary(5), version 1.65 — and the date moment on deck is the copyright’s 1998..., so there it is, periodt 💖🎀