IEC-ATA

IEC-ATA is a hard drive controller for the Commodore IEC serial bus. It enables all computers that has an IEC serial bus port (e.g VIC-20, C-64, C-128) to use cheap, easy to get ATA hard drives (also called IDE hard drives).

Description

Features:

• Supports standard ATA hard drives up to 128 gigabytes
• The whole disk is available as one big partition
• Supports standard Commodore KERNAL IEC disk commands. This has a number of implications:
  • May be connected to any computer with an IEC serial bus port (VIC-20, C-64, C-128, and probably others...)
  • No driver software is necessary on the computer, the hard drive works like a disk drive with a giant disk in it
  • The IEC bus is very slow, making the hard drive slow. But it is considerably faster than the 1541 disk drive.
• Custom file system that has the following features:
  • Supports PRG, and SEQ file types, and a new DIR file type that represents subdirectories
  • Smallest addressable unit: 512 bytes (one ATA logical block)
  • Max file size: 32 megabytes
  • Max number of directory entries: 256
  • Max number of nested subdirectories: unlimited

IEC-ATA has some limitations:

• Don't support USR and REL file types
• Don't support all Commodore DOS commands, especially the memory read/write/execute and block read/write/allocate/free. This implicates that fastloaders, copyprotected games and other programs doing more excotic things with the disk drive won't work. See the readme.txt file included with the schematics and software for more information about which Commodore DOS commands are supported.

The IEC-ATA controller card contains an AVR 8515 microcontroller with 32 kilobytes of external SRAM. For more information about the hardware, download the schematics.

Note

• I have not done anything on this design since 2002.
• It contains some shortcomings and bugs, so beware of this before starting building.
• I will not build one for you, even if you offer me money.

Download

You may download the schematics (ps and pdf), PCB layout files (ps) and software source code (ANSI C) here. The schematics are public domain, the source code is released under the GNU general public license.

If you want an alternative (more compact) layout with gerber files made by Novák József, download them here.

Pictures