diff --git a/Makefile b/Makefile
index f8b824de..1ba18634 100644
--- a/Makefile
+++ b/Makefile
@@ -196,14 +196,14 @@ $(call do-encodedecodetest,cmd_fd2000)
 $(call do-encodedecodetest,hplif,,--264)
 $(call do-encodedecodetest,hplif,,--616)
 $(call do-encodedecodetest,hplif,,--770)
-$(call do-encodedecodetest,ibm1200)
-$(call do-encodedecodetest,ibm1232)
-$(call do-encodedecodetest,ibm1440)
-$(call do-encodedecodetest,ibm180)
-$(call do-encodedecodetest,ibm160)
-$(call do-encodedecodetest,ibm320)
-$(call do-encodedecodetest,ibm360)
-$(call do-encodedecodetest,ibm720)
+$(call do-encodedecodetest,ibm,,--1200)
+$(call do-encodedecodetest,ibm,,--1232)
+$(call do-encodedecodetest,ibm,,--1440)
+$(call do-encodedecodetest,ibm,,--180)
+$(call do-encodedecodetest,ibm,,--160)
+$(call do-encodedecodetest,ibm,,--320)
+$(call do-encodedecodetest,ibm,,--360)
+$(call do-encodedecodetest,ibm,,--720)
 $(call do-encodedecodetest,mac400,scripts/mac400_test.textpb)
 $(call do-encodedecodetest,mac800,scripts/mac800_test.textpb)
 $(call do-encodedecodetest,n88basic)
diff --git a/doc/disk-ibm.md b/doc/disk-ibm.md
index baaed48f..b8953f08 100644
--- a/doc/disk-ibm.md
+++ b/doc/disk-ibm.md
@@ -38,15 +38,16 @@ Reading disks
 
 Just do:
 
-    fluxengine read `<format>`
+    fluxengine read ibm `<format>`
 
-...and you'll end up with a `<format>.img` file. This should work on most PC
-disks (including FM 360kB disks, 3.5" 1440kB disks, 5.25" 1200kB disks, etc.)
-The size of the disk image will vary depending on the format.
+...and you'll end up with an `ibm.img` file. You'll need to specify which
+format to use; this can be one of `--160`, `--180`, `--320`, `--360`, `--720`,
+`--1200`, `--1232` or `--1400` depending. The size of the disk image will vary
+depending on the format.
 
-The common PC formats are `ibm720` and `ibm1440`, but there are _many_ others,
+The common PC formats are `--720` and `--1440`, but there are _many_ others,
 and there's too many configuration options to usefully list. Use `fluxengine
-write` to list all formats, and try `fluxengine write ibm1440 --config` to see
+write` to list all formats, and try `fluxengine write ibm --1440 --config` to see
 a sample configuration.
 
 Configuration options you'll want include:
@@ -84,16 +85,13 @@ makes things slightly awkward. Preconfigured profiles are available.
 
 The syntax is:
 
-    fluxengine write <format> -i input.img <options>
+    fluxengine write ibm <format> -i input.img <options>
 
-The common PC formats are `ibm720` and `ibm1440`, but there are _many_ others,
-and there's too many configuration options to usefully list. Use `fluxengine
-write` to list all formats, and try `fluxengine write ibm1440 --config` to see
-a sample configuration.
+See above for the formats.
 
 Some image formats, such as DIM, specify the image format, For these you can
-specify the `ibm` format and FluxEngine will automatically determine the
-correct format to use.
+specify the `--auto` format (which is the default) and FluxEngine will
+automatically determine the correct format to use.
 
 Mixed-format disks
 ------------------
@@ -131,11 +129,7 @@ drives, feature "tri-mode" support which in addition to normal 300rpm modes,
 can change their speed to read and write 360rpm DD and HD disks.
 
 Neither the FluxEngine or Greaseweazle hardware can currently command a
-tri-mode drive to spin at 360rpm, however an older 360rpm-only drive will work
-to read these formats.
+tri-mode drive to spin at 360rpm. However on both devices the FluxEngine
+software is capable of both reading and writing 300rpm disks at 360rpm and vice
+versa, so it shouldn't matter.
 
-Alternately, the FluxEngine software can rescale the flux pulses to enable
-reading and writing these formats with a plain 300rpm drive. To do this,
-specify the following two additional options:
-
-    --flux_source.rescale=1.2 --flux_sink.rescale=1.2
diff --git a/src/formats/build.mk b/src/formats/build.mk
index 6a5e97ca..77f7ec30 100644
--- a/src/formats/build.mk
+++ b/src/formats/build.mk
@@ -22,14 +22,6 @@ FORMATS = \
 	fb100 \
 	hplif \
 	ibm \
-	ibm1200 \
-	ibm1232 \
-	ibm1440 \
-	ibm180 \
-	ibm160 \
-	ibm360 \
-	ibm320 \
-	ibm720 \
 	icl30 \
 	mac400 \
 	mac800 \
diff --git a/src/formats/ibm.textpb b/src/formats/ibm.textpb
index 3f229a83..d9311fea 100644
--- a/src/formats/ibm.textpb
+++ b/src/formats/ibm.textpb
@@ -1,4 +1,9 @@
-comment: 'PC 3.5"/5.25" autodetect double sided format'
+comment: 'Generic PC 3.5"/5.25" family'
+
+image_reader {
+	filename: "ibm.img"
+	type: IMG
+}
 
 image_writer {
 	filename: "ibm.img"
@@ -9,9 +14,255 @@ decoder {
 	ibm {}
 }
 
-heads {
-	start: 0
-	end: 1
+filesystem {
+	type: FATFS
 }
 
+tpi: 96
+
+option_group {
+	comment: "Format variant"
+
+	option {
+		name: "auto"
+		comment: 'try to autodetect the format (unreliable)'
+		set_by_default: true
+
+		config {}
+	}
+
+	option {
+		name: "160"
+		comment: '160kB 5.25" 40-track 8-sector SSDD'
+
+		config {
+			layout {
+				tracks: 40
+				sides: 1
+				layoutdata {
+					sector_size: 512
+					physical {
+						start_sector: 1
+						count: 8
+					}
+				}
+			}
+
+			encoder {
+				ibm {
+					trackdata {
+						target_rotational_period_ms: 167
+						target_clock_period_us: 3.333
+					}
+				}
+			}
+
+			tpi: 48
+		}
+	}
+
+	option {
+		name: "180"
+		comment: '180kB 5.25" 40-track 9-sector SSDD'
+
+		config {
+			layout {
+				tracks: 40
+				sides: 1
+				layoutdata {
+					sector_size: 512
+					physical {
+						start_sector: 1
+						count: 9
+					}
+				}
+			}
+
+			encoder {
+				ibm {
+					trackdata {
+						target_rotational_period_ms: 167
+						target_clock_period_us: 3.333
+					}
+				}
+			}
+
+			tpi: 48
+		}
+	}
+
+	option {
+		name: "320"
+		comment: '320kB 5.25" 40-track 8-sector DSDD'
+
+		config {
+			layout {
+				tracks: 40
+				sides: 2
+				layoutdata {
+					sector_size: 512
+					physical {
+						start_sector: 1
+						count: 8
+					}
+				}
+			}
+
+			encoder {
+				ibm {
+					trackdata {
+						target_rotational_period_ms: 167
+						target_clock_period_us: 3.333
+					}
+				}
+			}
+
+			tpi: 48
+		}
+	}
+
+	option {
+		name: "360"
+		comment: '360kB 5.25" 40-track 9-sector DSDD'
+
+		config {
+			layout {
+				tracks: 40
+				sides: 2
+				layoutdata {
+					sector_size: 512
+					physical {
+						start_sector: 1
+						count: 9
+					}
+				}
+			}
+
+			encoder {
+				ibm {
+					trackdata {
+						target_rotational_period_ms: 167
+						target_clock_period_us: 3.333
+					}
+				}
+			}
+
+			tpi: 48
+		}
+	}
+
+	option {
+		name: "720"
+		comment: '720kB 5.25"/3.5" 80-track 9-sector DSDD'
+
+		config {
+			layout {
+				tracks: 80
+				sides: 2
+				layoutdata {
+					sector_size: 512
+					physical {
+						start_sector: 1
+						count: 9
+					}
+				}
+			}
+
+			encoder {
+				ibm {
+					trackdata {
+						# This also works on 166ms drives (producing a physical clock of
+						# 3.33us).
+						target_rotational_period_ms: 200
+						target_clock_period_us: 4
+					}
+				}
+			}
+		}
+	}
+
+	option {
+		name: "1200"
+		comment: '1200kB 5.25" 80-track 15-sector DSHD'
+
+		config {
+			layout {
+				tracks: 80
+				sides: 2
+				layoutdata {
+					sector_size: 512
+					physical {
+						start_sector: 1
+						count: 15
+					}
+				}
+			}
+
+			encoder {
+				ibm {
+					trackdata {
+						target_rotational_period_ms: 167
+						target_clock_period_us: 2
+					}
+				}
+			}
+		}
+	}
+
+	option {
+		name: "1232"
+		comment: '1232kB 5.25"/3.5" 77-track 8-sector DSHD'
+
+		config {
+			layout {
+				tracks: 77
+				sides: 2
+				layoutdata {
+					sector_size: 1024
+					physical {
+						start_sector: 1
+						count: 8
+					}
+				}
+			}
+
+			encoder {
+				ibm {
+					trackdata {
+						target_rotational_period_ms: 167
+						target_clock_period_us: 2
+					}
+				}
+			}
+		}
+	}
+
+	option {
+		name: "1440"
+		comment: '1440kB 3.5" 80-track 18-sector DSHD'
+
+		config {
+			layout {
+				tracks: 80
+				sides: 2
+				layoutdata {
+					sector_size: 512
+					physical {
+						start_sector: 1
+						count: 18
+					}
+				}
+			}
+
+			encoder {
+				ibm {
+					trackdata {
+						target_rotational_period_ms: 200
+						target_clock_period_us: 2
+					}
+				}
+			}
+		}
+	}
+}
 
diff --git a/src/formats/ibm1200.textpb b/src/formats/ibm1200.textpb
deleted file mode 100644
index c624b1dd..00000000
--- a/src/formats/ibm1200.textpb
+++ /dev/null
@@ -1,46 +0,0 @@
-comment: 'PC 1200kB 5.25" 80-track 15-sector DSHD'
-
-image_reader {
-	filename: "ibm1200.img"
-	type: IMG
-}
-
-image_writer {
-	filename: "ibm1200.img"
-	type: IMG
-}
-
-layout {
-	tracks: 80
-	sides: 2
-	layoutdata {
-		sector_size: 512
-		physical {
-			start_sector: 1
-			count: 15
-		}
-	}
-}
-
-encoder {
-	ibm {
-		trackdata {
-			target_rotational_period_ms: 167
-			target_clock_period_us: 2
-		}
-	}
-}
-
-decoder {
-	ibm {}
-}
-
-drive {
-	high_density: true
-}
-
-filesystem {
-	type: FATFS
-}
-
-
diff --git a/src/formats/ibm1440.textpb b/src/formats/ibm1440.textpb
deleted file mode 100644
index e28490b9..00000000
--- a/src/formats/ibm1440.textpb
+++ /dev/null
@@ -1,41 +0,0 @@
-comment: 'PC 1440kB 3.5" 80-track 18-sector DSHD'
-
-image_reader {
-	filename: "ibm1440.img"
-	type: IMG
-}
-
-image_writer {
-	filename: "ibm1440.img"
-	type: IMG
-}
-
-layout {
-	tracks: 80
-	sides: 2
-	layoutdata {
-		sector_size: 512
-		physical {
-			start_sector: 1
-			count: 18
-		}
-	}
-}
-
-encoder {
-	ibm {
-		trackdata {
-			target_rotational_period_ms: 200
-			target_clock_period_us: 2
-		}
-	}
-}
-
-decoder {
-	ibm {}
-}
-
-filesystem {
-	type: FATFS
-}
-
diff --git a/src/formats/ibm160.textpb b/src/formats/ibm160.textpb
deleted file mode 100644
index 498fb64f..00000000
--- a/src/formats/ibm160.textpb
+++ /dev/null
@@ -1,48 +0,0 @@
-comment: 'PC 160kB 5.25" 40-track 8-sector SSDD'
-
-image_reader {
-	filename: "ibm160.img"
-	type: IMG
-}
-
-image_writer {
-	filename: "ibm160.img"
-	type: IMG
-}
-
-layout {
-	tracks: 40
-	sides: 1
-	layoutdata {
-		sector_size: 512
-		physical {
-			start_sector: 1
-			count: 8
-		}
-	}
-}
-
-encoder {
-	ibm {
-		trackdata {
-			target_rotational_period_ms: 167
-			target_clock_period_us: 3.333
-		}
-	}
-}
-
-decoder {
-	ibm {}
-}
-
-drive {
-	high_density: false
-}
-
-tpi: 48
-
-filesystem {
-	type: FATFS
-}
-
-
diff --git a/src/formats/ibm180.textpb b/src/formats/ibm180.textpb
deleted file mode 100644
index 4bc63f82..00000000
--- a/src/formats/ibm180.textpb
+++ /dev/null
@@ -1,48 +0,0 @@
-comment: 'PC 180kB 5.25" 40-track 9-sector SSDD'
-
-image_reader {
-	filename: "ibm180.img"
-	type: IMG
-}
-
-image_writer {
-	filename: "ibm180.img"
-	type: IMG
-}
-
-layout {
-	tracks: 40
-	sides: 1
-	layoutdata {
-		sector_size: 512
-		physical {
-			start_sector: 1
-			count: 9
-		}
-	}
-}
-
-encoder {
-	ibm {
-		trackdata {
-			target_rotational_period_ms: 167
-			target_clock_period_us: 3.333
-		}
-	}
-}
-
-decoder {
-	ibm {}
-}
-
-drive {
-	high_density: false
-}
-
-tpi: 48
-
-filesystem {
-	type: FATFS
-}
-
-
diff --git a/src/formats/ibm320.textpb b/src/formats/ibm320.textpb
deleted file mode 100644
index 5ba7e3c8..00000000
--- a/src/formats/ibm320.textpb
+++ /dev/null
@@ -1,44 +0,0 @@
-comment: 'PC 320kB 5.25" 40-track 8-sector DSDD'
-
-image_reader {
-	filename: "ibm320.img"
-	type: IMG
-}
-
-image_writer {
-	filename: "ibm320.img"
-	type: IMG
-}
-
-layout {
-	tracks: 40
-	sides: 2
-	layoutdata {
-		sector_size: 512
-		physical {
-			start_sector: 1
-			count: 8
-		}
-	}
-}
-
-encoder {
-	ibm {
-		trackdata {
-			target_rotational_period_ms: 167
-			target_clock_period_us: 3.333
-		}
-	}
-}
-
-decoder {
-	ibm {}
-}
-
-tpi: 48
-
-filesystem {
-	type: FATFS
-}
-
-
diff --git a/src/formats/ibm360.textpb b/src/formats/ibm360.textpb
deleted file mode 100644
index 780ed59f..00000000
--- a/src/formats/ibm360.textpb
+++ /dev/null
@@ -1,44 +0,0 @@
-comment: 'PC 360kB 5.25" 40-track 9-sector DSDD'
-
-image_reader {
-	filename: "ibm360.img"
-	type: IMG
-}
-
-image_writer {
-	filename: "ibm360.img"
-	type: IMG
-}
-
-layout {
-	tracks: 40
-	sides: 2
-	layoutdata {
-		sector_size: 512
-		physical {
-			start_sector: 1
-			count: 9
-		}
-	}
-}
-
-encoder {
-	ibm {
-		trackdata {
-			target_rotational_period_ms: 167
-			target_clock_period_us: 3.333
-		}
-	}
-}
-
-decoder {
-	ibm {}
-}
-
-tpi: 48
-
-filesystem {
-	type: FATFS
-}
-
-
diff --git a/src/formats/ibm720.textpb b/src/formats/ibm720.textpb
deleted file mode 100644
index 9b4672b8..00000000
--- a/src/formats/ibm720.textpb
+++ /dev/null
@@ -1,47 +0,0 @@
-comment: 'PC 720kB 5.25"/3.5" 80-track 9-sector DSDD'
-
-image_reader {
-	filename: "ibm720.img"
-	type: IMG
-}
-
-image_writer {
-	filename: "ibm720.img"
-	type: IMG
-}
-
-layout {
-	tracks: 80
-	sides: 2
-	layoutdata {
-		sector_size: 512
-		physical {
-			start_sector: 1
-			count: 9
-		}
-	}
-}
-
-encoder {
-	ibm {
-		trackdata {
-			# This also works on 166ms drives (producing a physical clock of
-			# 3.33us).
-			target_rotational_period_ms: 200
-			target_clock_period_us: 4
-		}
-	}
-}
-
-decoder {
-	ibm {}
-}
-
-drive {
-	high_density: false
-}
-
-filesystem {
-	type: FATFS
-}
-