ZuluIDE-firmware

What the hardware does

ZuluIDE is a hardware interface between the IDE bus and SD cards, and the firmware repository documents two generations. ZuluIDE V2 is powered by the RP2350B microcontroller, while the original ZuluIDE RP2040 uses the RP2040 microcontroller and a small FPGA. The first generation is still supported, but V2 has permanently succeeded it because it is faster and cheaper to produce. V2 can emulate rigid hard drives, ATAPI or IDE CD ROM drives, ATAPI or IDE Zip drives and a generic ATAPI removable drive, including two devices, a primary and a secondary, at the same time. All image files live on a FAT32 or exFAT formatted SD card. The homepage is zuluide.com, and the firmware is the software that makes the board present as classic storage to old computers and consoles that expect an IDE device.

Drive types and image handling

There are three ways to specify drive type. An image filename prefix can be CDRM for a CD ROM drive, HDDR for a hard drive, ZIPD for a Zip Drive 100, or REMV for a generic removable device. The zuluide.ini file can set a Device value such as CDROM, Zip100 or Removable. If neither is used, the drive defaults to CD ROM. For CD ROM emulation, iso images and bin or cue files are supported, loaded alphabetically with preference given to prefixed files. Zip and removable drives accept any extension except the ignored ones, used in alphabetic order. A prefix used to specify the drive must be shared by all files inserted into that drive. For rigid hard disk emulation any raw file format works, and later firmware supports Virtual Hard Disk Version 1 images, though V2 is not supported. CD audio playback emulation is functional on both generations, with the RP2350 generating digital i2s audio sent to an onboard or optional DAC board using a PCM5100A converter.

Operation and limitations

Cycling images is supported both by a hardware eject button on V2 boards and a pin header for a switch, and by sending the eject command from the operating system to load the next image alphabetically. V2 also supports dual device operation where a single board presents as both primary and secondary on the IDE bus, with the dual drive required to be a hard drive while the main device can be any type. USB mass storage access to the SD card can be enabled through an ini directive, with details and limits on a wiki page. Log files record operations, and the README points to an ignored list of files that will never be used as device images. The repository carries 128 stars and 12 forks with 24 open issues, the default branch is main, and the license is marked NOASSERTION in the metadata rather than a standard SPDX identifier, so users should check the repository for the actual terms.

Editorial conclusion

ZuluIDE firmware is a NOASSERTION licensed IDE to SD emulator on the main branch with 128 stars that runs on RP2040 and RP2350B boards, emulates CD ROM, hard drive and Zip media from FAT32 or exFAT SD images, and offers dual device operation on V2.