IBMWRITER

This project has been ported to C++. The python version has been archived at https://github.com/MasonGulu/ibm-cassette-maker-py. This will convert binary and ascii files into a format that can be loaded over the IBM PC's cassette port.

Usage: ibmwriter <bin, bas, raw, img> input basic_name [flags]

Modes:

• bin - write a binary file with basic header
• bas - write an ascii basic listing with basic header
• raw - write a binary file without a basic header
• img - write a 320kb disk image with proper delays and spacing.
  • See below.

Flags:

• Set the segment/offset in the basic header. Have yet to find anything that this matters for. Defaults to 0.
  • -segment=<value>
  • -offset=<value>
• -86box Increase the bitrate to 44.1kHz for 86box compat. ~11x larger files and I've yet to have issues loading at the 4kHz default bitrate.

Cassette loading tips

I recommend maxing out your volume. If you constantly get errors when loading over cassette try a different playback device.

When writing a 320kb disk if you encounter an error loading a track you can easily resume from where you left off. To the left of the most recent "Expecting" message is a 2 digit number in hexidecimal. Open your diskimage audio file in a visual audio editor, count out the "blocks" of audio (starting at 0) until you reach that hex number. Push a button on the 5150 to try to load off cassette again, and resume the audio file right before the block you counted.

Writing a 320kb boot disk over the cassette port.

This program contains additional functionality to enable creating a 320kb boot disk over the cassette port.

Quickstart

diskimage.wav is a Dos 3.3 boot disk with debug.com, a text editor, and several disk tools. Download floppy.wav and diskimage.wav from the releases section.

• Boot your 5150/compatible to BASIC and run the following commands.
  • def seg = &h2000
  • bload"floppy",0
• Play floppy.wav into your cassette input.
  • Once the basic header plays you should see "floppy.M found", let the file continue loading.
• Once the file finishes loading run the following commands.
  • o = 0
  • call o
• Insert a 5 1/4" disk into drive A
• Push 1 to format the disk.
  • If the disk fails to format it probably has bad sectors, try a different disk.
• Push 2 to write the disk.
  • Push anyting but escape at the prompt and start playing diskimage.wav.
  • THIS WILL TAKE 40+ MINUTES.

Using your own disk images

The disk image you want to use has to be in an img raw format, and must be 320kb. This program does not support writing 360kb disks.

• Take your disk image and run ibmwriter with the following parameters
  • ibmwriter img disk.img disk
• Follow the instructions under Quickstart for the audio files you created.

floppy.bin

This is an 8086 assembly program that will format a floppy and then write track by track information that's loaded from the cassette port. This program is only intended to be run on an IBM 5150 and does NOT follow standards expected by later PCs. The presense of an XT-IDE will cause the program to function incorrectly. REMOVE YOUR XT-IDE FROM THE 5150/compatible BEFORE ATTEMPTING TO USE THIS PROGRAM.

Assembling floppy.bin

If you want to assemble the floppy formatting/writing program follow these steps.

• Ensure your working directory is the floppytools/ directory
• Install nasm and run the following command
  • nasm main.asm -o floppy.bin
• Run ibmwriter with the following parameters, adjusting to fit your directory structure. This will produce a file called floppy. This is a wave file, you can rename the file to include the extension afterwards.
  • ibmwriter bin floppy.bin floppy