diff --git a/README.md b/README.md
index 104cc7df..7870220b 100644
--- a/README.md
+++ b/README.md
@@ -132,7 +132,7 @@ choices because they can store multiple types of file system.
 | [`n88basic`](doc/disk-n88basic.md) | N88-BASIC: PC8800/PC98 5.25" 77-track 26-sector DSHD | 🦄 | 🦄 |  |
 | [`northstar`](doc/disk-northstar.md) | Northstar: 5.25" hard sectored | 🦄 | 🦄 |  |
 | [`psos`](doc/disk-psos.md) | pSOS: 800kB DSDD with PHILE | 🦄 | 🦄 | PHILE  |
-| [`rolandd20`](doc/disk-rolandd20.md) | Roland D20: 3.5" electronic synthesiser disks | 🦖 |  | ROLAND  |
+| [`rolandd20`](doc/disk-rolandd20.md) | Roland D20: 3.5" electronic synthesiser disks | 🦄 | 🦖 | ROLAND  |
 | [`rx50`](doc/disk-rx50.md) | Digital RX50: 400kB 5.25" 80-track 10-sector SSDD | 🦖 | 🦖 |  |
 | [`smaky6`](doc/disk-smaky6.md) | Smaky 6: 308kB 5.25" 77-track 16-sector SSDD, hard sectored | 🦖 |  | SMAKY6  |
 | [`tids990`](doc/disk-tids990.md) | Texas Instruments DS990: 1126kB 8" DSSD | 🦖 | 🦖 |  |
diff --git a/doc/disk-rolandd20.md b/doc/disk-rolandd20.md
index b1f59b45..682aa8d3 100644
--- a/doc/disk-rolandd20.md
+++ b/doc/disk-rolandd20.md
@@ -9,9 +9,13 @@ drive, used for saving MIDI sequences and samples.
 Weirdly, it seems to use precisely the same format as the Brother word
 processors: a thoroughly non-IBM-compatible custom GCR system.
 
-FluxEngine pretends to support this, but it has had almost no testing, the only
-disk image I have seen for it was mostly corrupt, and very little is known
-about the format, so I have no idea whether it's correct or not.
+FluxEngine supports both reading and writing D20 disks, as well as basic support
+for the filesystem, allowing files to be read from and written to D20 disks.
+Note that the D20 was never intended to support arbitrary files on its disks and
+is very likely to crash if you put unexpected files on a disk. In addition,
+while the file format itself is currently unknown, there is a header at the top
+of the file containing what appears to be the name shown in the D20 file
+browser, so the name by which you see it is not necessarily the filename.
 
 Please [get in touch](https://github.com/davidgiven/fluxengine/issues/new) if
 you know anything about it.
diff --git a/src/formats/rolandd20.textpb b/src/formats/rolandd20.textpb
index 7c60144d..f63cae38 100644
--- a/src/formats/rolandd20.textpb
+++ b/src/formats/rolandd20.textpb
@@ -1,6 +1,7 @@
 shortname: 'Roland D20'
 comment: '3.5" electronic synthesiser disks'
-read_support_status: DINOSAUR
+read_support_status: UNICORN
+write_support_status: DINOSAUR
 
 documentation:
 <<<
@@ -10,14 +11,23 @@ drive, used for saving MIDI sequences and samples.
 Weirdly, it seems to use precisely the same format as the Brother word
 processors: a thoroughly non-IBM-compatible custom GCR system.
 
-FluxEngine pretends to support this, but it has had almost no testing, the only
-disk image I have seen for it was mostly corrupt, and very little is known
-about the format, so I have no idea whether it's correct or not.
+FluxEngine supports both reading and writing D20 disks, as well as basic support
+for the filesystem, allowing files to be read from and written to D20 disks.
+Note that the D20 was never intended to support arbitrary files on its disks and
+is very likely to crash if you put unexpected files on a disk. In addition,
+while the file format itself is currently unknown, there is a header at the top
+of the file containing what appears to be the name shown in the D20 file
+browser, so the name by which you see it is not necessarily the filename.
 
 Please [get in touch](https://github.com/davidgiven/fluxengine/issues/new) if
 you know anything about it.
 >>>
 
+image_reader {
+	filename: "rolandd20.img"
+	type: IMAGETYPE_IMG
+}
+
 image_writer {
 	filename: "rolandd20.img"
 	type: IMAGETYPE_IMG