Analysis of ROM image for Norsk Data VDU 301 S

This repository is meant to analyze the ROM images from Norsk Data VDU 301 S as provided at by Torfinn.

To combine the two ROM image halves and extract the font portion of it:

python3 extract-nd.py

You should get a rom-nd-vdu-301-s.bin with the complete ROM image and a font-nd-vdu-301-s.bin that contains the font part of the ROM and finally a font-nd-vdu-301-s.ppm that is a Netpbm image showing each character of the font.

There are 770 black/white characters in font-nd-vdu-301-s.bin concatenated without intervening padding. Each character is 8 pixels wide and 15 rows tall, i.e. one row of pixels per byte for a total of 15 bytes. A bit set to 1 should be interpreted as black color while a bit cleared to 0 should be interpreted as white color.

You should get a rom.bin with the complete ROM image and a font.bin that contains the font part of the ROM and finally a font.ppm that is a Netpbm image showing each character of the font.

This is the output to expect, albeit converted to PNG:

The liberty was also taken to include the analysis of the Tandberg TDV 2200/9 S t ROM image also provided by Torfinn.

The font can similarly be extracted like so:

python3 extract-tdv.py

You should get a font-tdv-2200-9-s.ppm based on the original ROM image which contains 1024 character concatenated without intervening padding. Each character is 8 pixels wide and 16 rows tall, for a total of 16 bytes. Like for ND VDU 301 S above, a bit set to 1 should be interpreted as black color while a bit cleared to 0 should be interpreted as white color.

This is the output to expect for TDV 2200/9 S, albeit converted to PNG: