SD Card Setup¶

PicoIDE uses a microSD card to store disk and CD-ROM images along with configuration settings.

Requirements¶

microSD card (newer cards are recommended)
FAT32 or exFAT formatted with MBR partitioning. Formatting with the SD Association's SD Card Formatter is strongly recommended!

Card Selection

While most microSD cards work fine, higher-speed cards (Class 10 or UHS-I) provide better performance.

Directory Layout¶

The following is an example directory structure on the SD card. cdrom/ and hdd/ are default locations for those types of images but they can be put elsewhere on the card.

/
├── cdrom/                      # CD-ROM images (ATAPI)
│   ├── game.iso
│   ├── album.cue
│   ├── album.bin
│   └── Big Game/               # Subdirectories supported
│       └── Disc 1.iso
│       └── Disc 2.iso
├── hdd/                        # Hard disk images (IDE)
│   ├── dos622.img
│   └── windows98.vhd
├── firmware/                   # Firmware update files
│   ├── picoide.uf2             # Main board firmware
│   └── picoide-frontpanel.bin  # Front panel firmware
└── picoide.ini                 # Configuration file

Supported File Formats¶

The file type of an image also determines which kind of device PicoIDE emulates for it. See Configuration File for more detail.

CD-ROM (ATAPI)¶

Extension	Description
`.iso`	ISO 9660 disc image
`.cue`	CUE sheet with associated `.bin` file(s)
`.toast`	Disc image commonly used on vintage Macs

bin/cue Images

For bin/cue CD images, place the .cue file and all referenced .bin files in the same directory. PicoIDE supports audio tracks for CD music playback.

Hard Disk (IDE)¶

Extension	Description
`.vhd`	Virtual Hard Disk (supports baked-in CHS geometry)
`.img`	Raw disk image
`.hda`	Raw disk image
`.hdf`	Raw disk image (Amiga, RDB format only)

VHD Images

Only fixed VHD images are supported. Dynamic and differencing VHD images will not work.

86Box is great for creating VHD images with arbitrary CHS geometry and setting them up ahead of time.

HDF Images

Amiga "hardfile" HDF images are not supported - only raw images including the RDB are supported. Images created from actual Amiga disks or partitioned RDB images from Amiga emulators will work.

Configuration File¶

The picoide.ini file controls which devices PicoIDE emulates and which images they load at startup. Place it in the root of your SD card. If you have the front panel installed, you can also edit this file from the web interface.

Each emulated device is described by its own section, [device0] and [device1]. Which of them are used depends on the M/S/CS jumper (see Device Selection):

Jumper	Sections used
M, S, or CS (single-device mode)	`[device0]` only, which configures the one emulated device determined by the jumper. `[device1]` is ignored
none (dual-device mode)	`[device0]` describes device 0 and `[device1]` describes device 1

Example Configuration¶

A single device that boots from a hard disk image:

# PicoIDE Configuration File

[device0]
image = /hdd/windows98.img

PicoIDE determines the device type to emulate from the image's file extension, so in most cases the image line is all you need.

In dual-device mode, add a [device1] section for the second device:

[device0]
image = /hdd/windows98.img

[device1]
image = /cdrom/game.iso

This config has both a hard disk and a CD-ROM drive, but each device can independently be either type depending on what's in the .ini file.

Configuration Reference¶

`[device0]` and `[device1]` Sections¶

Setting	Values	Default	Description
`image`	path	(empty)	Image to load at startup, and what the device type is inferred from. Empty = load the first image found alphabetically in `browse_dir`
`type`	`cdrom`, `hdd`	`cdrom`	Which device to emulate. Usually unnecessary, as it's inferred from `image`, but if `image` is empty this will be used
`browse_dir`	path	`/cdrom` or `/hdd`, depending on device type	Directory to browse for images, and to auto-load the first image from when `image` is empty
`auto_load`	`true`, `false`	`true`	Load an image at startup. Set to `false` to start with an empty CD-ROM drive

Device type is inferred from the file type of image:

Image file type	Device emulated
`.iso`, `.cue`, `.toast`	CD-ROM (ATAPI)
`.img`, `.vhd`, `.hda`, `.hdf`	Hard disk (IDE)

Set type explicitly when there's no image to infer from, for example if you want an empty CD-ROM drive that you'll load a disc into later from the front panel:

[device0]
type = cdrom
auto_load = false

Automatic image Updating

When you select a different image using the front panel, web interface, or host control, that device's image setting is automatically updated to remember your selection.

`[overrides]` Section¶

Advanced settings to override the maximum transfer mode, IDENTIFY responses, etc. to fix compatibility issues with certain vintage computers. They apply to the IDE bus as a whole, so in dual-device mode both devices share them.

Setting	Values	Default	Description
`max_pio_mode`	`0`-`4`	`4`	Maximum PIO transfer mode
`max_mwdma_mode`	`0`-`2` or `-1`	`2`	Maximum Multi-word DMA mode (`-1` disables DMA)
`disable_iordy`	`true`, `false`	`false`	Disable IORDY flow control
`sector_delay_us`	`0`-`1000`	`0`	Delay in microseconds between sectors during multi-sector PIO reads
`mwdma_cycle_time`	`120`-`1200` or `0`	`0`	Multi-word DMA cycle time in ns (`0` = standard minimum for the advertised mode)
`bus_delay`	`1.0`-`6.0`	`1.0`	Bus timing delay factor for slow or noisy IDE buses

Example for forcing PIO-only operation:

[overrides]
max_mwdma_mode = -1

Example for disabling IORDY flow control (for older systems with IORDY issues, or for a small speed boost on tolerant systems):

[overrides]
disable_iordy = true

Example for fixing hangs during boot on systems with BIOSes that expect to see BSY between sectors:

[overrides]
sector_delay_us = 100

Example for the beige Power Macintosh G3, which needs slightly slower Multi-word DMA burst timing than the 120ns default:

[overrides]
mwdma_cycle_time = 180

Example for slowing bus timing on very old systems (e.g., IBM 5170):

[overrides]
bus_delay = 6.0

Auto-Mount Behavior¶

Each device mounts an image at startup independently, following its own section:

With image set: Loads that image. If it can't be loaded, falls back to the first image found in the browse directory
With image empty: Loads the first image found alphabetically in the browse directory
With auto_load = false: Loads nothing, leaving an empty CD-ROM drive

This allows for completely headless operation - just power on and the configured image is ready.

Auto-mount for hard disks

If a hard disk device can't load an image, the host will see errors, as PicoIDE currently only supports emulating a fixed (non-removable) disk. auto_load = false is only useful for CD-ROM devices.

Tips¶

Organizing Images¶

Use subdirectories to organize your collection:

/cdrom/
├── games/
│   ├── doom.iso
│   ├── quake.iso
│   └── big game/
│       ├── disc 1.iso
│       └── disc 2.iso
├── os install/
│   └── win98cd.iso
└── music/
    └── album.cue

Case Insensitivity¶

Paths and file names specified in picoide.ini are case-insensitive due to the FAT file system on the SD card.