adfExplorer (version 0.1.8)

boot.block.code: Minimal executable code for a bootblock

Description

A minimal piece of code required to boot to a command line interface on a Commodore Amiga.

Format

A data frame with two columns. The first column contains the assembled code (as raw data). The second column contains the corresponding Motorola 68000 (the main CPU of the original Commodore Amiga) assembly syntax.

Details

The first two blocks (amigaDisk) are special and are called the boot block. This block should contain information on the type of disk and possibly some executable code that will be run at boot time. This data.frame contains some minimal executable code that will start the Amiga command line interface. On Amiga OS \>=2.0 the screen will stay black unless a startup-sequence file is present on the disk.

The original code is from Thomas Kessler as published by Laurent Clévy (http://lclevy.free.fr/adflib/adf_info.html).

Examples

data("boot.block.code")

## To create a basic boot block for a DD disk:
bblock <- new("amigaBlock", data =
  c(as.raw(c(0x44, 0x4F, 0x53, 0x00, 0xE3, 0x3D, 0x0E, 0x73,
  0x00, 0x00, 0x03, 0x70)), unlist(boot.block.code$assembled),
  raw(419))
)
## The raw data preceding the executable code are
## a label, flags and a checksum.