Making a Kickstart disk for the Amiga 1000 using only a PC-compatible

Making a Kickstart disk for the Amiga 1000 using only a PC-compatible

The Commodore Amiga line of computers were known for their superior (at the time) graphics and sound and a highly integrated GUI that was ahead of its time, but they had one nagging attribute that made them less accessible and less hackable than the Commodore computers that had come before them: They all required a disk to boot. Unlike the Commodore 64 (and even earlier Commodore machines that predated the C64, like the PET and VIC-20), a diskless Amiga would not boot to a BASIC interface built into ROM. Rather, most Amigas would simply display an image asking you to insert a disk containing Workbench, the standard GUI environment for the Amiga. Although you didn't specifically need a Workbench disk (many programs other than Workbench can be placed in the drive and booted when this screen appears), the point is that an Amiga is basically useless without a disk.

The Amiga 1000, however--the very first Amiga model made--was even more disk-reliant than its later cousins, as it required not one but two floppy disks to boot. The second disk was Workbench, but the first disk required was Kickstart, the name of what is, essentially, the Amiga's ROM BIOS code. The Amiga 1000 was made to load its BIOS off a floppy disk rather than from ROM, and so it contains very little internal ROM code except that needed to read a floppy. This was done so that the Amiga's BIOS could be easily upgraded without having to physically swap out the ROM chip (this was in the days before Flash or EEPROM memory upgrades were widely available). While this opens up certain interesting possibilities for hackers, as it means you can literally rewrite the machine's BIOS and easily load it off a floppy disk, this also means that if you have an Amiga 1000 sitting around that you want to use, you're basically stuck unless you can provide a floppy containing some bootable Amiga code.

It turns out that a common IBM PC-compatible running Windows can be made to produce a working Kickstart disk for an Amiga 1000, although the process requires some special hardware and software. This page endeavors to explain how this can be done.

First of all, here's a list of things you will need to make this process happen:

- A working Kickstart ROM file. Because these are copyrighted, they are not freely available, although you can sometimes find them floating around on the Internet. Note that for this process to work properly, you'll want a copy of Kickstart that boots off DF1: (the second Amiga floppy drive) and not DF0: (the first floppy drive).
- A copy of WriteKickDisk. This is a puublic-domain program for the Amiga which will write a bootable Kickstart disk from a Kickstart ROM file. You can find it on Aminet, the de facto site for Amiga files, but in case Aminet is down for whatever reason, I've included a link to version 1.3 (the latest as of this writing) here.
- A working copy of WinUAE. Because WriiteKickDisk is a program written to actually run on an Amiga, you need an Amiga emulator to run it on. The de facto Amiga emulator for Windows is WinUAE. It can be freely downloaded from its homepage at www.winuae.net.
- A copy of ADF Opus. This is a Windowss program which lets you work with .ADF files (the standard format for Amiga disk images). ADF Opus lets you open ADF files as if they were folders, and you can drag-and-drop files to or from ADF images easily. ADF Opus is free and open-source (nice!); you can download it from adfopus.sourceforge.net.
- A working Catweasel. This is a circuiit board made to plug into a PC which acts as a floppy controller. It can write floppies in the Amiga format, which is important since a standard PC floppy controller can't do this no matter what software you use. The Catweasel is made by Individual Computers and you can find more information at their website: www.ami.ga. Classic versions of the Catweasel were ISA cards, but there is now a PCI version available as well. Note that despite the fact that Windows 98 drivers are included with the latest versions of the Catweasel, these don't actually work; the Catweasel is fundamentally a Windows 2000/XP device.

That's quite a list, but luckily, most of it is free software. The only parts that might be difficult to get are the Kickstart ROM image, because it's copyrighted, and the Catweasel, because it's actual hardware and you'll probably have to pay for it.

Assuming you've actually gathered all these items, let's proceed with the process you'll need to cull a Kickstart disk.

Your first step is to make the ADF that you'll run WriteKickDisk from. Run ADF Opus and click on the "New" button to create a new ADF. Type the name you want to use for this ADF file; for the purposes of this procedure, I'm going to use the name WKD.ADF (WKD being an acronym for WriteKickDisk). Also turn on the "Bootable" and "Open after creating" check boxes. An empty window showing the contents of your new ADF file should pop up. Now, using the "Windows Directory" window in the background, you want to drag two files to your new ADF: One is your Kickstart ROM file. The other is the WriteKickDisk executable, which is the file in the WriteKickDisk archive that is just called "WriteKickDisk", with no extension. Drag these two files into your new ADF. You can now close this ADF.

Still in ADF Opus, click the New button again, and make another new ADF called KICKDISK.ADF. Click "Create", then go ahead and close ADF Opus; its work is done.

Now it's time to use your new ADF files. Run WinUAE, and insert WKD.ADF into DF1:, and KICKDISK.ADF into DF0:. Make sure that WKD.ADF is loaded into DF1: (the second floppy drive), because WriteKickDisk will write the Kickstart disk image to DF0: (the first floppy drive), and if the WriteKickDisk program is in DF0:, then it's going to trash itself before it can finish running. When these two ADF files have been loaded into WinUAE, make sure WinUAE is configured to work as an Amiga 500 or 2000, and boot it!

Because the WKD.ADF disk has only minimal boot code on it (as created by ADF Opus when you turned on the "Bootable" option), it will simply end at a command-line interface. That's perfectly fine, because the only program you need is already available on DF1:. Switch to that drive by typing df1: and pressing ENTER. Now type WriteKickDisk KICK31.ROM, where KICK31.ROM is, of course, the name of the Kickstart ROM image you copied to this ADF. WriteKickDisk will run for quite some time, and when it's done, it will verify the write to make sure the image was written correctly. When you return to the command prompt, you can exit WinUAE. KICKDISK.ADF is now a working Kickstart disk image!

The only remaining step is to get this ADF image onto an actual Amiga floppy disk. Here's where the Catweasel comes in. Insert a blank floppy disk into your PC's floppy drive. (Of course, the disk doesn't actually have to be blank, but if it's not, whatever is on it will be overwritten.) Run the imagetool.exe program that comes with the CatWeasel drivers. Under the "Buffer" section on the right-hand side, click the "Load" button. Find and double-click the KICKDISK.ADF file. The imagetool program defaults to an 880k Amiga DD 3.5" floppy format, which is what you want to use, so leave it at that. Now you can just click the "write" button. The program will chug away on the floppy for a while, and when it's done, the floppy disk will now be a usable Amiga Kickstart disk! Stick this disk into an Amiga 1000, turn it on, and marvel at the splendor that is the image prompting you for a Workbench disk! Well, at least you got past the similar image prompting you for a Kickstart disk. Now you can put in a standard Amiga disk and run a program from it, just as you would with an Amiga 500 or any other Amiga with built-in Kickstart ROM.

A bit of a quick-start for those who've never used an Amiga before:

Like many other microcomputers, the Amiga uses a "three-finger salute" reboot code. It's CTRL-Amiga-Amiga (i.e. hold down the CTRL key and both "Amiga" keys at the same time). The "Amiga" keys are the ones with the red letter "A" on them.

The Amiga is a very mouse-centric computer; almost every program will probably require a mouse. The mouse ports are the two DB9 ports on the right-hand side of the machine (these are also used for joysticks). If you don't have a mouse but do have a joystick, you can use the joystick's button to behave like the left mouse button, but unfortunately, moving the actual stick around won't emulate moving the mouse around, so this is mostly useless.

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