Eliminate the broken tpi system for a simple drive/format type field.

2025-10-24 11:11:02 -07:00 · 2023-10-29 21:10:14 +01:00
parent ff1fb761f2
commit 533b217c8f
86 changed files with 1831 additions and 798 deletions
--- a/2
+++ b/2
@@ -1,6 +1,6 @@
 CC = gcc
 CXX = g++ -std=c++17
-CFLAGS = -g -Os
+CFLAGS = -g -O0
 LDFLAGS =

 OBJ = .obj
--- a/README.md
+++ b/README.md
@@ -103,45 +103,45 @@ particular filesystem and can read (and sometimes write, support varies) files
 directly from disks, flux files or disk images. Some formats have multiple
 choices because they can store multiple types of file system.

-<!-- FORMATSSTART -->
-<!-- This section is automatically generated. Do not edit. -->
-
-| Profile | Format | Read? | Write? | Filesystem? |
-|:--------|:-------|:-----:|:------:|:------------|
-| [`acornadfs`](doc/disk-acornadfs.md) | Acorn ADFS: BBC Micro, Archimedes | 🦖 |  |  |
-| [`acorndfs`](doc/disk-acorndfs.md) | Acorn DFS: Acorn Atom, BBC Micro series | 🦄 |  | ACORNDFS  |
-| [`aeslanier`](doc/disk-aeslanier.md) | AES Lanier "No Problem": 616kB 5.25" 77-track SSDD hard sectored | 🦖 |  |  |
-| [`agat`](doc/disk-agat.md) | Agat: 840kB 5.25" 80-track DS | 🦖 | 🦖 |  |
-| [`amiga`](doc/disk-amiga.md) | Amiga: 880kB 3.5" DSDD | 🦄 | 🦄 | AMIGAFFS  |
-| [`ampro`](doc/disk-ampro.md) | Ampro Little Board: CP/M | 🦖 |  | CPMFS  |
-| [`apple2`](doc/disk-apple2.md) | Apple II: Prodos, Appledos, and CP/M | 🦄 | 🦄 | APPLEDOS CPMFS PRODOS  |
-| [`atarist`](doc/disk-atarist.md) | Atari ST: Almost PC compatible | 🦄 | 🦄 |  |
-| [`bk`](doc/disk-bk.md) | BK: 800kB 5.25"/3.5" 80-track 10-sector DSDD | 🦖 | 🦖 |  |
-| [`brother`](doc/disk-brother.md) | Brother word processors: GCR family | 🦄 | 🦄 | BROTHER120 FATFS  |
-| [`commodore`](doc/disk-commodore.md) | Commodore: 1541, 1581, 8050 and variations | 🦄 | 🦄 | CBMFS  |
-| [`eco1`](doc/disk-eco1.md) | VDS Eco1: CP/M; 1210kB 77-track mixed format DSHD | 🦖 |  | CPMFS  |
-| [`epsonpf10`](doc/disk-epsonpf10.md) | Epson PF-10: CP/M; 3.5" 40-track DSDD | 🦖 |  | CPMFS  |
-| [`f85`](doc/disk-f85.md) | Durango F85: 461kB 5.25" 77-track SS | 🦖 |  |  |
-| [`fb100`](doc/disk-fb100.md) | Brother FB-100: 100kB 3.5" 40-track SSSD | 🦖 |  |  |
-| [`hplif`](doc/disk-hplif.md) | Hewlett-Packard LIF: a variety of disk formats used by HP | 🦄 | 🦄 | LIF  |
-| [`ibm`](doc/disk-ibm.md) | IBM PC: Generic PC 3.5"/5.25" disks | 🦄 | 🦄 | FATFS  |
-| [`icl30`](doc/disk-icl30.md) | ICL Model 30: CP/M; 263kB 35-track DSSD | 🦖 |  | CPMFS  |
-| [`mac`](doc/disk-mac.md) | Macintosh: 400kB/800kB 3.5" GCR | 🦄 | 🦄 | MACHFS  |
-| [`micropolis`](doc/disk-micropolis.md) | Micropolis: 100tpi MetaFloppy disks | 🦄 | 🦄 |  |
-| [`ms2000`](doc/disk-ms2000.md) | : MS2000 Microdisk Development System |  |  | MICRODOS  |
-| [`mx`](doc/disk-mx.md) | DVK MX: Soviet-era PDP-11 clone | 🦖 |  |  |
-| [`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  |
-| [`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 | 🦖 | 🦖 |  |
-| [`tiki`](doc/disk-tiki.md) | Tiki 100: CP/M |  |  | CPMFS  |
-| [`victor9k`](doc/disk-victor9k.md) | Victor 9000 / Sirius One: 1224kB 5.25" DSDD GCR | 🦖 | 🦖 |  |
-| [`zilogmcz`](doc/disk-zilogmcz.md) | Zilog MCZ: 320kB 8" 77-track SSSD hard-sectored | 🦖 |  | ZDOS  |
-{: .datatable }
-
+<!-- FORMATSSTART -->
+<!-- This section is automatically generated. Do not edit. -->
+
+| Profile | Format | Read? | Write? | Filesystem? |
+|:--------|:-------|:-----:|:------:|:------------|
+| [`acornadfs`](doc/disk-acornadfs.md) | Acorn ADFS: BBC Micro, Archimedes | 🦖 |  |  |
+| [`acorndfs`](doc/disk-acorndfs.md) | Acorn DFS: Acorn Atom, BBC Micro series | 🦄 |  | ACORNDFS  |
+| [`aeslanier`](doc/disk-aeslanier.md) | AES Lanier "No Problem": 616kB 5.25" 77-track SSDD hard sectored | 🦖 |  |  |
+| [`agat`](doc/disk-agat.md) | Agat: 840kB 5.25" 80-track DS | 🦖 | 🦖 |  |
+| [`amiga`](doc/disk-amiga.md) | Amiga: 880kB 3.5" DSDD | 🦄 | 🦄 | AMIGAFFS  |
+| [`ampro`](doc/disk-ampro.md) | Ampro Little Board: CP/M | 🦖 |  | CPMFS  |
+| [`apple2`](doc/disk-apple2.md) | Apple II: Prodos, Appledos, and CP/M | 🦄 | 🦄 | APPLEDOS CPMFS PRODOS  |
+| [`atarist`](doc/disk-atarist.md) | Atari ST: Almost PC compatible | 🦄 | 🦄 |  |
+| [`bk`](doc/disk-bk.md) | BK: 800kB 5.25"/3.5" 80-track 10-sector DSDD | 🦖 | 🦖 |  |
+| [`brother`](doc/disk-brother.md) | Brother word processors: GCR family | 🦄 | 🦄 | BROTHER120 FATFS  |
+| [`commodore`](doc/disk-commodore.md) | Commodore: 1541, 1581, 8050 and variations | 🦄 | 🦄 | CBMFS  |
+| [`eco1`](doc/disk-eco1.md) | VDS Eco1: CP/M; 1210kB 77-track mixed format DSHD | 🦖 |  | CPMFS  |
+| [`epsonpf10`](doc/disk-epsonpf10.md) | Epson PF-10: CP/M; 3.5" 40-track DSDD | 🦖 |  | CPMFS  |
+| [`f85`](doc/disk-f85.md) | Durango F85: 461kB 5.25" 77-track SS | 🦖 |  |  |
+| [`fb100`](doc/disk-fb100.md) | Brother FB-100: 100kB 3.5" 40-track SSSD | 🦖 |  |  |
+| [`hplif`](doc/disk-hplif.md) | Hewlett-Packard LIF: a variety of disk formats used by HP | 🦄 | 🦄 | LIF  |
+| [`ibm`](doc/disk-ibm.md) | IBM PC: Generic PC 3.5"/5.25" disks | 🦄 | 🦄 | FATFS  |
+| [`icl30`](doc/disk-icl30.md) | ICL Model 30: CP/M; 263kB 35-track DSSD | 🦖 |  | CPMFS  |
+| [`mac`](doc/disk-mac.md) | Macintosh: 400kB/800kB 3.5" GCR | 🦄 | 🦄 | MACHFS  |
+| [`micropolis`](doc/disk-micropolis.md) | Micropolis: 100tpi MetaFloppy disks | 🦄 | 🦄 |  |
+| [`ms2000`](doc/disk-ms2000.md) | : MS2000 Microdisk Development System |  |  | MICRODOS  |
+| [`mx`](doc/disk-mx.md) | DVK MX: Soviet-era PDP-11 clone | 🦖 |  |  |
+| [`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  |
+| [`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 | 🦖 | 🦖 |  |
+| [`tiki`](doc/disk-tiki.md) | Tiki 100: CP/M |  |  | CPMFS  |
+| [`victor9k`](doc/disk-victor9k.md) | Victor 9000 / Sirius One: 1224kB 5.25" DSDD GCR | 🦖 | 🦖 |  |
+| [`zilogmcz`](doc/disk-zilogmcz.md) | Zilog MCZ: 320kB 8" 77-track SSSD hard-sectored | 🦖 |  | ZDOS  |
+{: .datatable }
+
 <!-- FORMATSEND -->

 ### Notes
--- a/arch/micropolis/decoder.cc
+++ b/arch/micropolis/decoder.cc
@@ -67,28 +67,32 @@ static uint8_t b(uint32_t field, uint8_t pos)
 static uint8_t eccNextBit(uint32_t ecc, uint8_t data_bit)
 {
    // This is 0x81932080 which is 0x0104C981 with reversed bits
-    return b(ecc, 7) ^ b(ecc, 13) ^ b(ecc, 16) ^ b(ecc, 17) ^ b(ecc, 20)
-            ^ b(ecc, 23) ^ b(ecc, 24) ^ b(ecc, 31) ^ data_bit;
+    return b(ecc, 7) ^ b(ecc, 13) ^ b(ecc, 16) ^ b(ecc, 17) ^ b(ecc, 20) ^
+           b(ecc, 23) ^ b(ecc, 24) ^ b(ecc, 31) ^ data_bit;
 }

 uint32_t vectorGraphicEcc(const Bytes& bytes)
 {
    uint32_t e = 0;
-    Bytes payloadBytes = bytes.slice(0, bytes.size()-4);
+    Bytes payloadBytes = bytes.slice(0, bytes.size() - 4);
    ByteReader payload(payloadBytes);
-    while (!payload.eof()) {
+    while (!payload.eof())
+    {
        uint8_t byte = payload.read_8();
-        for (int i = 0; i < 8; i++) {
+        for (int i = 0; i < 8; i++)
+        {
            e = (e << 1) | eccNextBit(e, byte >> 7);
            byte <<= 1;
        }
    }
-    Bytes trailerBytes = bytes.slice(bytes.size()-4);
+    Bytes trailerBytes = bytes.slice(bytes.size() - 4);
    ByteReader trailer(trailerBytes);
    uint32_t res = e;
-    while (!trailer.eof()) {
+    while (!trailer.eof())
+    {
        uint8_t byte = trailer.read_8();
-        for (int i = 0; i < 8; i++) {
+        for (int i = 0; i < 8; i++)
+        {
            res = (res << 1) | eccNextBit(e, byte >> 7);
            e <<= 1;
            byte <<= 1;
@@ -101,13 +105,15 @@ uint32_t vectorGraphicEcc(const Bytes& bytes)
 static bool vectorGraphicEccFix(Bytes& bytes, uint32_t syndrome)
 {
    uint32_t ecc = syndrome;
-    int pos = (MICROPOLIS_ENCODED_SECTOR_SIZE-5)*8+7;
+    int pos = (MICROPOLIS_ENCODED_SECTOR_SIZE - 5) * 8 + 7;
    bool aligned = false;
-    while ((ecc & 0xff000000) == 0) {
+    while ((ecc & 0xff000000) == 0)
+    {
        pos += 8;
        ecc <<= 8;
    }
-    for (; pos >= 0; pos--) {
+    for (; pos >= 0; pos--)
+    {
        bool bit = ecc & 1;
        ecc >>= 1;
        if (bit)
@@ -119,7 +125,7 @@ static bool vectorGraphicEccFix(Bytes& bytes, uint32_t syndrome)
    }
    if (pos < 0)
        return false;
-    bytes[pos/8] ^= ecc >> 16;
+    bytes[pos / 8] ^= ecc >> 16;
    return true;
 }

@@ -199,9 +205,11 @@ public:

        bool eccPresent = bytes[274] == 0xaa;
        uint32_t ecc = 0;
-        if (_config.ecc_type() == MicropolisDecoderProto::VECTOR && eccPresent) {
+        if (_config.ecc_type() == MicropolisDecoderProto::VECTOR && eccPresent)
+        {
            ecc = vectorGraphicEcc(bytes.slice(0, 274));
-            if (ecc != 0) {
+            if (ecc != 0)
+            {
                vectorGraphicEccFix(bytes, ecc);
                ecc = vectorGraphicEcc(bytes.slice(0, 274));
            }
--- a/arch/micropolis/encoder.cc
+++ b/arch/micropolis/encoder.cc
@@ -49,7 +49,8 @@ static void write_sector(std::vector<bool>& bits,

        uint8_t eccPresent = 0;
        uint32_t ecc = 0;
-        if (eccType == MicropolisEncoderProto::VECTOR) {
+        if (eccType == MicropolisEncoderProto::VECTOR)
+        {
            eccPresent = 0xaa;
            ecc = vectorGraphicEcc(sectorData + Bytes(4));
        }
@@ -98,23 +99,25 @@ public:
        unsigned prev_cursor = 0;
        unsigned cursor = 0;

-        for (const auto& sectorData : sectors) {
+        for (const auto& sectorData : sectors)
+        {
            indexes.push_back(cursor);
            prev_cursor = cursor;
            write_sector(bits, cursor, sectorData, _config.ecc_type());
        }
-        indexes.push_back(prev_cursor + (cursor - prev_cursor)/2);
+        indexes.push_back(prev_cursor + (cursor - prev_cursor) / 2);
        indexes.push_back(cursor);

        if (cursor != bits.size())
            error("track data mismatched length");

        std::unique_ptr<Fluxmap> fluxmap(new Fluxmap);
-        nanoseconds_t clockPeriod = calculatePhysicalClockPeriod(
-            _config.clock_period_us() * 1e3,
-            _config.rotational_period_ms() * 1e6);
+        nanoseconds_t clockPeriod =
+            calculatePhysicalClockPeriod(_config.clock_period_us() * 1e3,
+                _config.rotational_period_ms() * 1e6);
        auto pos = bits.begin();
-        for (int i = 1; i < indexes.size(); i++) {
+        for (int i = 1; i < indexes.size(); i++)
+        {
            auto end = bits.begin() + indexes[i];
            fluxmap->appendBits(std::vector<bool>(pos, end), clockPeriod);
            fluxmap->appendIndex();
--- a/build.py
+++ b/build.py
@@ -224,53 +224,53 @@ if not glob("../fluxengine-testdata/data"):
    print("fluxengine-testdata not found; skipping corpus tests")
 else:
    corpus = [
-        ("agat", "", "--drive.tpi=96"),
-        ("amiga", "", "--drive.tpi=135"),
-        ("apple2", "", "--140 --drive.tpi=96"),
-        ("atarist", "", "--360 --drive.tpi=135"),
-        ("atarist", "", "--370 --drive.tpi=135"),
-        ("atarist", "", "--400 --drive.tpi=135"),
-        ("atarist", "", "--410 --drive.tpi=135"),
-        ("atarist", "", "--720 --drive.tpi=135"),
-        ("atarist", "", "--740 --drive.tpi=135"),
-        ("atarist", "", "--800 --drive.tpi=135"),
-        ("atarist", "", "--820 --drive.tpi=135"),
+        ("agat", "", ""),
+        ("amiga", "", ""),
+        ("apple2", "", "--140 40track_drive"),
+        ("atarist", "", "--360"),
+        ("atarist", "", "--370"),
+        ("atarist", "", "--400"),
+        ("atarist", "", "--410"),
+        ("atarist", "", "--720"),
+        ("atarist", "", "--740"),
+        ("atarist", "", "--800"),
+        ("atarist", "", "--820"),
        ("bk", "", ""),
-        ("brother", "", "--120 --drive.tpi=135"),
-        ("brother", "", "--240 --drive.tpi=135"),
+        ("brother", "", "--120 40track_drive"),
+        ("brother", "", "--240"),
        (
            "commodore",
            "scripts/commodore1541_test.textpb",
-            "--171 --drive.tpi=96",
+            "--171 40track_drive",
        ),
        (
            "commodore",
            "scripts/commodore1541_test.textpb",
-            "--192 --drive.tpi=96",
+            "--192 40track_drive",
        ),
-        ("commodore", "", "--800 --drive.tpi=135"),
-        ("commodore", "", "--1620 --drive.tpi=135"),
-        ("hplif", "", "--264 --drive.tpi=135"),
-        ("hplif", "", "--608 --drive.tpi=135"),
-        ("hplif", "", "--616 --drive.tpi=135"),
-        ("hplif", "", "--770 --drive.tpi=135"),
-        ("ibm", "", "--1200 --drive.tpi=96"),
-        ("ibm", "", "--1232 --drive.tpi=96"),
-        ("ibm", "", "--1440 --drive.tpi=135"),
-        ("ibm", "", "--1680 --drive.tpi=135"),
-        ("ibm", "", "--180 --drive.tpi=96"),
-        ("ibm", "", "--160 --drive.tpi=96"),
-        ("ibm", "", "--320 --drive.tpi=96"),
-        ("ibm", "", "--360 --drive.tpi=96"),
-        ("ibm", "", "--720_96 --drive.tpi=96"),
-        ("ibm", "", "--720_135 --drive.tpi=135"),
-        ("mac", "scripts/mac400_test.textpb", "--400 --drive.tpi=135"),
-        ("mac", "scripts/mac800_test.textpb", "--800 --drive.tpi=135"),
-        ("n88basic", "", "--drive.tpi=96"),
-        ("rx50", "", "--drive.tpi=96"),
-        ("tids990", "", "--drive.tpi=48"),
-        ("victor9k", "", "--612 --drive.tpi=96"),
-        ("victor9k", "", "--1224 --drive.tpi=96"),
+        ("commodore", "", "--800"),
+        ("commodore", "", "--1620"),
+        ("hplif", "", "--264"),
+        ("hplif", "", "--608"),
+        ("hplif", "", "--616"),
+        ("hplif", "", "--770"),
+        ("ibm", "", "--1200"),
+        ("ibm", "", "--1232"),
+        ("ibm", "", "--1440"),
+        ("ibm", "", "--1680"),
+        ("ibm", "", "--180 40track_drive"),
+        ("ibm", "", "--160 40track_drive"),
+        ("ibm", "", "--320 40track_drive"),
+        ("ibm", "", "--360 40track_drive"),
+        ("ibm", "", "--720_96"),
+        ("ibm", "", "--720_135"),
+        ("mac", "scripts/mac400_test.textpb", "--400"),
+        ("mac", "scripts/mac800_test.textpb", "--800"),
+        ("n88basic", "", ""),
+        ("rx50", "", ""),
+        ("tids990", "", ""),
+        ("victor9k", "", "--612"),
+        ("victor9k", "", "--1224"),
    ]

    for c in corpus:
@@ -285,11 +285,11 @@ else:
                    + c[0]
                    + " "
                    + format
-                    + " {ins[0]} "
+                    + " {ins[0]} '"
                    + c[1]
-                    + " "
+                    + "' '"
                    + c[2]
-                    + ">/dev/null"
+                    + "' $(dir {outs[0]}) > /dev/null"
                ],
                label="CORPUSTEST",
            )
--- a/lib/build.py
+++ b/lib/build.py
@@ -19,7 +19,7 @@ proto(
        "./usb/usb.proto",
        "./vfs/vfs.proto",
    ],
-    deps=[".+common_proto"],
+    deps=[".+common_proto", "+fl2_proto"],
 )

 protocc(name="config_proto_lib", srcs=[".+config_proto", "arch+arch_proto"])
--- a/lib/config.cc
+++ b/lib/config.cc
@@ -172,7 +172,6 @@ ConfigProto* Config::combined()
        /* First apply any standalone options. */

        std::set<std::string> options = _appliedOptions;
-        std::set<const OptionPrerequisiteProto*> prereqs;
        for (const auto& option : _baseConfig.option())
        {
            if (options.find(option.name()) != options.end())
--- a/lib/config.h
+++ b/lib/config.h
@@ -52,7 +52,8 @@ class InapplicableValueException : public ErrorException
 public:
    InapplicableValueException():
        ErrorException("selected format cannot be used here")
-    {}
+    {
+    }
 };

 struct FluxConstructor
--- a/lib/drive.proto
+++ b/lib/drive.proto
@@ -1,8 +1,9 @@
 syntax = "proto2";

 import "lib/common.proto";
+import "lib/fl2.proto";

-// Next: 17
+// Next: 15
 message DriveProto
 {
    optional int32 drive = 1
@@ -11,32 +12,30 @@ message DriveProto
        [ default = INDEXMODE_DRIVE, (help) = "index pulse source" ];
    optional int32 hard_sector_count = 3
        [ default = 0, (help) = "number of hard sectors on disk" ];
-    optional double hard_sector_threshold_ns = 16
+    optional double hard_sector_threshold_ns = 4
        [ default = 0, (help) = "index pulses longer than this interval are "
            "considered sector markers; shorter indicates an true index marker" ];
-    optional bool high_density = 4
+    optional bool high_density = 5
        [ default = true, (help) = "set if this is a high density disk" ];
-    optional bool sync_with_index = 5
+    optional bool sync_with_index = 6
        [ default = false, (help) = "start reading at index mark" ];
-    optional double revolutions = 6
+    optional double revolutions = 7
        [ default = 1.2, (help) = "number of revolutions to read" ];

-    optional int32 tracks = 7
+    optional int32 tracks = 8
        [ default = 81, (help) = "Number of tracks supported by drive" ];
-    optional int32 heads = 8
+    optional int32 heads = 9
        [ default = 2, (help) = "Number of heads supported by drive" ];
-    optional int32 head_bias = 9 [
+    optional int32 head_bias = 10 [
        default = 0,
        (help) = "Bias to apply to the head position (in tracks)"
    ];
-    optional int32 group_offset = 14 [
+    optional int32 group_offset = 11 [
        default = 0,
        (help) = "When writing groups, erase all tracks except this one in each group"
    ];
-    optional int32 head_width = 10
-        [ default = 1, (help) = "Width of the head (in tracks)" ];
-    optional float tpi = 11 [ default = 0, (help) = "TPI of drive; 0 disables all track mapping" ];
-    optional double rotational_period_ms = 12
+    optional DriveType drive_type = 12 [ default = DRIVETYPE_UNKNOWN, (help) = "Type of drive" ];
+    optional double rotational_period_ms = 13
        [ default = 0, (help) = "Rotational period of the drive in milliseconds (0 to autodetect)"];

    enum ErrorBehaviour {
@@ -45,7 +44,7 @@ message DriveProto
        RECALIBRATE = 2;
    }

-    optional ErrorBehaviour error_behaviour = 15
+    optional ErrorBehaviour error_behaviour = 14
        [ default = JIGGLE, (help) = "what to do when an error occurs during reads" ];
 }

--- a/lib/fl2.proto
+++ b/lib/fl2.proto
@@ -15,11 +15,28 @@ message TrackFluxProto {
 	repeated bytes flux = 3;
 }

+enum DriveType {
+	DRIVETYPE_UNKNOWN = 0;
+	DRIVETYPE_40TRACK = 1;
+	DRIVETYPE_80TRACK = 2;
+	DRIVETYPE_APPLE2 = 3;
+}
+
+enum FormatType {
+	FORMATTYPE_UNKNOWN = 0;
+	FORMATTYPE_40TRACK = 1;
+	FORMATTYPE_80TRACK = 2;
+}
+
+// NEXT: 8
 message FluxFileProto {
 	optional int32 magic = 1;
 	optional FluxFileVersion version = 2;
 	repeated TrackFluxProto track = 3;
 	optional double rotational_period_ms = 4;
-	optional int32 tpi = 5;
+	optional DriveType drive_type = 6 [default = DRIVETYPE_UNKNOWN];
+	optional FormatType format_type = 7 [default = FORMATTYPE_UNKNOWN];
+
+	reserved 5;
 }

--- a/lib/fluxsink/fl2fluxsink.cc
+++ b/lib/fluxsink/fl2fluxsink.cc
@@ -45,7 +45,8 @@ public:

        proto.set_rotational_period_ms(
            globalConfig()->drive().rotational_period_ms());
-        proto.set_tpi(globalConfig()->drive().tpi());
+        proto.set_drive_type(globalConfig()->drive().drive_type());
+        proto.set_format_type(globalConfig()->layout().format_type());
        saveFl2File(_filename, proto);
    }

--- a/lib/fluxsink/scpfluxsink.cc
+++ b/lib/fluxsink/scpfluxsink.cc
@@ -55,7 +55,7 @@ public:
        _fileheader.start_track = strackno(minTrack, minSide);
        _fileheader.end_track = strackno(maxTrack, maxSide);
        _fileheader.flags = SCP_FLAG_INDEXED;
-        if (globalConfig()->drive().tpi() != 48)
+        if (globalConfig()->drive().drive_type() != DRIVETYPE_40TRACK)
            _fileheader.flags |= SCP_FLAG_96TPI;
        _fileheader.cell_width = 0;
        if ((minSide == 0) && (maxSide == 0))
--- a/lib/fluxsource/a2rfluxsource.cc
+++ b/lib/fluxsource/a2rfluxsource.cc
@@ -80,13 +80,14 @@ public:
                    /* 5.25" with quarter stepping. */
                    _extraConfig.mutable_drive()->set_tracks(160);
                    _extraConfig.mutable_drive()->set_heads(1);
-                    _extraConfig.mutable_drive()->set_head_width(4);
-                    _extraConfig.mutable_drive()->set_tpi(48 * 4);
+                    _extraConfig.mutable_drive()->set_drive_type(
+                        DRIVETYPE_APPLE2);
                }
                else
                {
                    /* 3.5". */
-                    _extraConfig.mutable_drive()->set_tpi(135);
+                    _extraConfig.mutable_drive()->set_drive_type(
+                        DRIVETYPE_80TRACK);
                }

                Bytes stream = findChunk("STRM");
--- a/lib/fluxsource/fl2fluxsource.cc
+++ b/lib/fluxsource/fl2fluxsource.cc
@@ -39,8 +39,8 @@ public:

        _extraConfig.mutable_drive()->set_rotational_period_ms(
            _proto.rotational_period_ms());
-        if (_proto.has_tpi())
-            _extraConfig.mutable_drive()->set_tpi(_proto.tpi());
+        if (_proto.has_drive_type())
+            _extraConfig.mutable_drive()->set_drive_type(_proto.drive_type());
    }

 public:
--- a/lib/fluxsource/scpfluxsource.cc
+++ b/lib/fluxsource/scpfluxsource.cc
@@ -42,8 +42,9 @@ public:
            (_header.file_id[2] != 'P'))
            error("input not a SCP file");

-        int tpi = (_header.flags & SCP_FLAG_96TPI) ? 96 : 48;
-        _extraConfig.mutable_drive()->set_tpi(tpi);
+        _extraConfig.mutable_drive()->set_drive_type(
+            (_header.flags & SCP_FLAG_96TPI) ? DRIVETYPE_80TRACK
+                                             : DRIVETYPE_40TRACK);

        _resolution = 25 * (_header.resolution + 1);
        int startSide = (_header.heads == 2) ? 1 : 0;
--- a/lib/imagereader/d88imagereader.cc
+++ b/lib/imagereader/d88imagereader.cc
@@ -61,13 +61,13 @@ public:
        if (mediaFlag == 0x20)
        {
            _extraConfig.mutable_drive()->set_high_density(true);
-            _extraConfig.mutable_layout()->set_tpi(96);
+            _extraConfig.mutable_layout()->set_format_type(FORMATTYPE_80TRACK);
        }
        else
        {
            clockRate = 300;
            _extraConfig.mutable_drive()->set_high_density(false);
-            _extraConfig.mutable_layout()->set_tpi(48);
+            _extraConfig.mutable_layout()->set_format_type(FORMATTYPE_40TRACK);
        }

        auto layout = _extraConfig.mutable_layout();
--- a/lib/imagereader/nfdimagereader.cc
+++ b/lib/imagereader/nfdimagereader.cc
@@ -58,7 +58,7 @@ public:
        log("NFD: HD 1.2MB mode");
        log("NFD: forcing hign density mode");
        _extraConfig.mutable_drive()->set_high_density(true);
-        _extraConfig.mutable_layout()->set_tpi(96);
+        _extraConfig.mutable_layout()->set_format_type(FORMATTYPE_80TRACK);

        std::unique_ptr<Image> image(new Image);
        for (int track = 0; track < 163; track++)
--- a/lib/layout.cc
+++ b/lib/layout.cc
@@ -2,34 +2,49 @@
 #include "lib/layout.h"
 #include "lib/proto.h"
 #include "lib/logger.h"
-
-bool approximatelyEqual(float a, float b, float epsilon)
-{
-    return fabs(a - b) <= ((fabs(a) < fabs(b) ? fabs(b) : fabs(a)) * epsilon);
-}
+#include "lib/fl2.h"

 static unsigned getTrackStep()
 {
-    if (globalConfig()->layout().tpi() == 0)
-        error("no layout TPI set");
-    if (globalConfig()->drive().tpi() == 0)
-        return 1;
+    auto format_type = globalConfig()->layout().format_type();
+    auto drive_type = globalConfig()->drive().drive_type();

-    if (globalConfig()->layout().tpi() == 0.0)
-        error("layout TPI is zero; this shouldn't happen?");
+    switch (format_type)
+    {
+        case FORMATTYPE_40TRACK:
+            switch (drive_type)
+            {
+                case DRIVETYPE_40TRACK:
+                    return 1;

-    float trackStepFactor =
-        globalConfig()->drive().tpi() / globalConfig()->layout().tpi();
+                case DRIVETYPE_80TRACK:
+                    return 2;

-    if (!approximatelyEqual(trackStepFactor, round(trackStepFactor), 0.001))
-        error(
-            "this drive can't handle this image, because the drive TPI doesn't "
-            "divide neatly into the layout TPI");
-    if (trackStepFactor < 0.999)
-        error(
-            "this drive can't handle this image, because the head is too big");
+                case DRIVETYPE_APPLE2:
+                    return 4;
+            }

-    return round(trackStepFactor);
+        case FORMATTYPE_80TRACK:
+            switch (drive_type)
+            {
+                case DRIVETYPE_40TRACK:
+                    error(
+                        "you can't write an 80 track image to a 40 track "
+                        "drive");
+
+                case DRIVETYPE_80TRACK:
+                    return 1;
+
+                case DRIVETYPE_APPLE2:
+                    error(
+                        "you can't write an 80 track image to an Apple II "
+                        "drive");
+            }
+    }
+
+    warning(
+        "don't know the drive and format types; performing 1:1 track mapping");
+    return 1;
 }

 unsigned Layout::remapTrackPhysicalToLogical(unsigned ptrack)
@@ -237,3 +252,15 @@ std::shared_ptr<const TrackInfo> Layout::getLayoutOfTrackPhysical(
    return getLayoutOfTrack(remapTrackPhysicalToLogical(physicalTrack),
        remapSidePhysicalToLogical(physicalSide));
 }
+
+int Layout::getHeadWidth()
+{
+    switch (globalConfig()->drive().drive_type())
+    {
+        case DRIVETYPE_APPLE2:
+            return 4;
+
+        default:
+            return 1;
+    }
+}
--- a/lib/layout.h
+++ b/lib/layout.h
@@ -52,6 +52,9 @@ public:
    /* Expand a SectorList into the actual sector IDs. */
    static std::vector<unsigned> expandSectorList(
        const SectorListProto& sectorsProto);
+
+    /* Return the head width of the current drive. */
+    static int getHeadWidth();
 };

 class TrackInfo
--- a/lib/layout.proto
+++ b/lib/layout.proto
@@ -1,6 +1,7 @@
 syntax = "proto2";

 import "lib/common.proto";
+import "lib/fl2.proto";

 message SectorListProto
 {
@@ -57,5 +58,6 @@ message LayoutProto
        [ default = CHS, (help) = "the order of sectors in the filesystem" ];
    optional bool swap_sides = 5
        [ default = false, (help) = "the sides are inverted on this disk" ];
-    optional float tpi = 6 [ (help) = "TPI of image; if 0, use TPI of drive" ];
+    optional FormatType format_type = 6
+        [ default = FORMATTYPE_UNKNOWN, (help) = "Format type of image" ];
 }
--- a/lib/proto.cc
+++ b/lib/proto.cc
@@ -288,8 +288,7 @@ std::string getProtoFieldValue(ProtoField& protoField)
        case google::protobuf::FieldDescriptor::TYPE_ENUM:
        {
            const auto* enumvalue = reflection->GetEnum(*message, field);
-            const auto* enumfield = field->enum_type();
-            return enumfield->name();
+            return enumvalue->name();
        }

        case google::protobuf::FieldDescriptor::TYPE_MESSAGE:
--- a/lib/readerwriter.cc
+++ b/lib/readerwriter.cc
@@ -218,7 +218,7 @@ ReadResult readGroup(FluxSourceIteratorHolder& fluxSourceIteratorHolder,
    ReadResult result = BAD_AND_CAN_NOT_RETRY;

    for (unsigned offset = 0; offset < trackInfo->groupSize;
-         offset += globalConfig()->drive().head_width())
+         offset += Layout::getHeadWidth())
    {
        auto& fluxSourceIterator = fluxSourceIteratorHolder.getIterator(
            trackInfo->physicalTrack + offset, trackInfo->physicalSide);
@@ -274,7 +274,7 @@ void writeTracks(FluxSink& fluxSink,
        for (;;)
        {
            for (int offset = 0; offset < trackInfo->groupSize;
-                 offset += globalConfig()->drive().head_width())
+                 offset += Layout::getHeadWidth())
            {
                unsigned physicalTrack = trackInfo->physicalTrack + offset;

--- a/lib/usb/fluxengineusb.cc
+++ b/lib/usb/fluxengineusb.cc
@@ -76,7 +76,7 @@ public:
                "your FluxEngine firmware is at version {} but the client is "
                "for version {}; please upgrade",
                version,
-                (int) FLUXENGINE_PROTOCOL_VERSION);
+                (int)FLUXENGINE_PROTOCOL_VERSION);
    }

 private:
--- a/lib/vfs/lif.cc
+++ b/lib/vfs/lif.cc
@@ -214,7 +214,7 @@ private:
        _directoryBlock = rbr.read_be32();
        rbr.skip(4);
        _directorySize = rbr.read_be32();
-		rbr.skip(4);
+        rbr.skip(4);
        unsigned tracks = rbr.read_be32();
        unsigned heads = rbr.read_be32();
        unsigned sectors = rbr.read_be32();
--- a/lib/vfs/roland.cc
+++ b/lib/vfs/roland.cc
@@ -69,10 +69,10 @@ private:
        void putBlock(RolandFsFilesystem* fs, uint8_t offset, uint8_t block)
        {
            if (blocks.size() <= offset)
-                blocks.resize(offset+1);
+                blocks.resize(offset + 1);
            blocks[offset] = block;

-            length = (offset+1) * fs->_blockSectors * fs->_sectorSize;
+            length = (offset + 1) * fs->_blockSectors * fs->_sectorSize;
            attributes[Filesystem::LENGTH] = std::to_string(length);
        }

@@ -84,7 +84,7 @@ private:
                if (!blocknumber)
                    break;

-                putBlock(fs, offset+i, blocknumber);
+                putBlock(fs, offset + i, blocknumber);
            }
        }

@@ -336,7 +336,7 @@ private:
                else
                    de = it->second;

-                de->putBlocks(this, extent*16, direntBytes);
+                de->putBlocks(this, extent * 16, direntBytes);
            }
        }

--- a/lib/vfs/sectorinterface.h
+++ b/lib/vfs/sectorinterface.h
@@ -12,7 +12,7 @@ class Encoder;
 class SectorInterface
 {
 public:
-	virtual ~SectorInterface() {}
+    virtual ~SectorInterface() {}

 public:
    virtual std::shared_ptr<const Sector> get(
--- a/lib/vfs/vfs.cc
+++ b/lib/vfs/vfs.cc
@@ -281,9 +281,10 @@ Bytes Filesystem::getSector(unsigned track, unsigned side, unsigned sector)
 Bytes Filesystem::getLogicalSector(uint32_t number, uint32_t count)
 {
    if ((number + count) > _locations.size())
-        throw BadFilesystemException(
-            fmt::format("invalid filesystem: sector {} is out of bounds ({} maximum)",
-                number + count - 1, _locations.size()));
+        throw BadFilesystemException(fmt::format(
+            "invalid filesystem: sector {} is out of bounds ({} maximum)",
+            number + count - 1,
+            _locations.size()));

    Bytes data;
    ByteWriter bw(data);
--- a/scripts/encodedecodetest.sh
+++ b/scripts/encodedecodetest.sh
@@ -1,22 +1,21 @@
 #!/bin/sh
 set -e

-format=$1
-tmp=/tmp/$$-$format
-srcfile=$tmp.src.img
-fluxfile=$tmp.$2
-destfile=$tmp.dest.img
-fluxengine=$3
-shift
-shift
-shift
+format="$1"
+ext="$2"
+fluxengine="$3"
+script="$4"
+flags="$5"
+dir="$6"

-trap "rm -f $srcfile $fluxfile $destfile" EXIT
+srcfile=$dir.$format.src.img
+fluxfile=$dir.$format.$ext
+destfile=$dir.$format.dest.img

 dd if=/dev/urandom of=$srcfile bs=1048576 count=2 2>&1

-$fluxengine write $format -i $srcfile -d $fluxfile --drive.rotational_period_ms=200 "$@"
-$fluxengine read $format -s $fluxfile -o $destfile --drive.rotational_period_ms=200 "$@"
+$fluxengine write $format -i $srcfile -d $fluxfile --drive.rotational_period_ms=200 $flags
+$fluxengine read $format -s $fluxfile -o $destfile --drive.rotational_period_ms=200 $flags
 if [ ! -s $destfile ]; then
 	echo "Zero length output file!" >&2
 	exit 1
--- a/src/fe-analysedriveresponse.cc
+++ b/src/fe-analysedriveresponse.cc
@@ -246,8 +246,7 @@ static void draw_x_graticules(Agg2D& painter,

 int mainAnalyseDriveResponse(int argc, const char* argv[])
 {
-    globalConfig().overrides()->mutable_flux_source()->set_type(
-        FLUXTYPE_DRIVE);
+    globalConfig().overrides()->mutable_flux_source()->set_type(FLUXTYPE_DRIVE);
    flags.parseFlagsWithConfigFiles(argc, argv, {});

    if (globalConfig()->flux_sink().type() != FLUXTYPE_DRIVE)
--- a/src/fe-inspect.cc
+++ b/src/fe-inspect.cc
@@ -131,8 +131,7 @@ static nanoseconds_t guessClock(const Fluxmap& fluxmap)

 int mainInspect(int argc, const char* argv[])
 {
-    globalConfig().overrides()->mutable_flux_source()->set_type(
-        FLUXTYPE_DRIVE);
+    globalConfig().overrides()->mutable_flux_source()->set_type(FLUXTYPE_DRIVE);
    flags.parseFlagsWithConfigFiles(argc, argv, {});

    auto& fluxSource = globalConfig().getFluxSource();
--- a/src/fe-ls.cc
+++ b/src/fe-ls.cc
@@ -57,8 +57,8 @@ int mainLs(int argc, const char* argv[])
                quote(dirent->filename),
                maxlen + 2,
                dirent->length,
-        				dirent->mode,
-        				dirent->attributes[Filesystem::CTIME]);
+                dirent->mode,
+                dirent->attributes[Filesystem::CTIME]);
            total += dirent->length;
        }
        fmt::print("({} files, {} bytes)\n", files.size(), total);
--- a/src/fe-rawread.cc
+++ b/src/fe-rawread.cc
@@ -53,8 +53,7 @@ int mainRawRead(int argc, const char* argv[])

    if (argc == 1)
        showProfiles("rawread", formats);
-    globalConfig().overrides()->mutable_flux_source()->set_type(
-        FLUXTYPE_DRIVE);
+    globalConfig().overrides()->mutable_flux_source()->set_type(FLUXTYPE_DRIVE);
    flags.parseFlagsWithConfigFiles(argc, argv, formats);

    if (globalConfig()->flux_sink().type() == FLUXTYPE_DRIVE)
--- a/src/fe-rawwrite.cc
+++ b/src/fe-rawwrite.cc
@@ -59,8 +59,7 @@ int mainRawWrite(int argc, const char* argv[])

    if (argc == 1)
        showProfiles("rawwrite", formats);
-    globalConfig().overrides()->mutable_flux_sink()->set_type(
-        FLUXTYPE_DRIVE);
+    globalConfig().overrides()->mutable_flux_sink()->set_type(FLUXTYPE_DRIVE);
    flags.parseFlagsWithConfigFiles(argc, argv, formats);

    if (globalConfig()->flux_source().type() == FLUXTYPE_DRIVE)
--- a/src/formats/40track_drive.textpb
+++ b/src/formats/40track_drive.textpb
@@ -16,8 +16,7 @@ fluxengine read ibm --180 40track_drive

 drive {
    tracks: 40
-    head_width: 1
-	tpi: 48
+    drive_type: DRIVETYPE_40TRACK
 }


--- a/src/formats/acornadfs.textpb
+++ b/src/formats/acornadfs.textpb
@@ -42,7 +42,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 1
 				layoutdata {
@@ -62,7 +62,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 1
 				layoutdata {
@@ -82,7 +82,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
@@ -102,7 +102,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
@@ -123,7 +123,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
--- a/src/formats/acorndfs.textpb
+++ b/src/formats/acorndfs.textpb
@@ -78,7 +78,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 			}
 		}
@@ -91,7 +91,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 			}
 		}
--- a/src/formats/aeslanier.textpb
+++ b/src/formats/aeslanier.textpb
@@ -51,7 +51,7 @@ decoder {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 77
 	sides: 1
 	layoutdata {
--- a/src/formats/agat.textpb
+++ b/src/formats/agat.textpb
@@ -32,7 +32,7 @@ image_writer {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 80
 	sides: 2
 	layoutdata {
--- a/src/formats/amiga.textpb
+++ b/src/formats/amiga.textpb
@@ -40,7 +40,7 @@ image_writer {
 }

 layout {
-	tpi: 135
+	format_type: FORMATTYPE_80TRACK
 	tracks: 80
 	sides: 2
 	layoutdata {
--- a/src/formats/ampro.textpb
+++ b/src/formats/ampro.textpb
@@ -82,7 +82,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 			}
 		}
@@ -94,7 +94,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 			}
 		}
--- a/src/formats/apple2.textpb
+++ b/src/formats/apple2.textpb
@@ -73,7 +73,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 35
 				sides: 1
 				layoutdata {
@@ -93,7 +93,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				order: HCS
--- a/src/formats/apple2_drive.textpb
+++ b/src/formats/apple2_drive.textpb
@@ -24,8 +24,7 @@ usb {
 drive {
    tracks: 160
    heads: 1
-    head_width: 4
-	tpi: 192
+    drive_type: DRIVETYPE_APPLE2
 }


--- a/src/formats/atarist.textpb
+++ b/src/formats/atarist.textpb
@@ -51,7 +51,7 @@ decoder {
 }

 layout {
-	tpi: 135
+	format_type: FORMATTYPE_80TRACK
 }

 option_group {
--- a/src/formats/bk.textpb
+++ b/src/formats/bk.textpb
@@ -28,7 +28,7 @@ image_writer {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 80
 	sides: 2
 	layoutdata {
--- a/src/formats/brother.textpb
+++ b/src/formats/brother.textpb
@@ -141,7 +141,7 @@ option_group {

 		config {
 			layout {
-				tpi: 67.5
+				format_type: FORMATTYPE_40TRACK
 				tracks: 39
 				sides: 1
 				layoutdata {
@@ -162,7 +162,7 @@ option_group {

 			drive {
 				head_bias: 0
-				group_offset: 1
+				group_offset: 0
 			}

 			filesystem {
@@ -178,7 +178,7 @@ option_group {

 		config {
 			layout {
-				tpi: 135
+				format_type: FORMATTYPE_80TRACK
 				tracks: 78
 				sides: 1
 				layoutdata {
--- a/src/formats/commodore.textpb
+++ b/src/formats/commodore.textpb
@@ -76,7 +76,7 @@ option_group {
 		
 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 35
 				sides: 1
 				layoutdata {
@@ -132,7 +132,7 @@ option_group {
 		
 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 1
 				layoutdata {
@@ -188,7 +188,7 @@ option_group {

 		config {
 			layout {
-				tpi: 135
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				swap_sides: true
@@ -230,7 +230,7 @@ option_group {
 		
 		config {
 			layout {
-				tpi: 100
+				format_type: FORMATTYPE_80TRACK
 				sides: 2
 				tracks: 77
 				layoutdata {
@@ -282,7 +282,7 @@ option_group {

 		config {
 			layout {
-				tpi: 135
+				format_type: FORMATTYPE_80TRACK
 				tracks: 81
 				sides: 2
 				swap_sides: true
--- a/src/formats/eco1.textpb
+++ b/src/formats/eco1.textpb
@@ -41,7 +41,7 @@ image_writer {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 77
 	sides: 2
 	layoutdata {
--- a/src/formats/epsonpf10.textpb
+++ b/src/formats/epsonpf10.textpb
@@ -15,7 +15,7 @@ image_writer {
 }

 layout {
-	tpi: 67.5
+	format_type: FORMATTYPE_40TRACK
 	tracks: 40
 	sides: 2
 	layoutdata {
--- a/src/formats/f85.textpb
+++ b/src/formats/f85.textpb
@@ -50,7 +50,7 @@ decoder {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 77
 	sides: 1
 	layoutdata {
--- a/src/formats/fb100.textpb
+++ b/src/formats/fb100.textpb
@@ -51,7 +51,7 @@ decoder {
 }

 layout {
-	tpi: 67.5
+	format_type: FORMATTYPE_40TRACK
 	tracks: 40
 	sides: 1
 	layoutdata {
--- a/src/formats/hplif.textpb
+++ b/src/formats/hplif.textpb
@@ -46,7 +46,7 @@ filesystem {
 }

 layout {
-	tpi: 135
+	format_type: FORMATTYPE_80TRACK
 }

 option_group {
--- a/src/formats/ibm.textpb
+++ b/src/formats/ibm.textpb
@@ -110,7 +110,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 			}
 		}
 	}
@@ -121,7 +121,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 1
 				layoutdata {
@@ -150,7 +150,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 1
 				layoutdata {
@@ -179,7 +179,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 2
 				layoutdata {
@@ -208,7 +208,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 2
 				layoutdata {
@@ -237,7 +237,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
@@ -266,7 +266,7 @@ option_group {

 		config {
 			layout {
-				tpi: 135
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
@@ -295,7 +295,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
@@ -324,7 +324,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 77
 				sides: 2
 				layoutdata {
@@ -353,7 +353,7 @@ option_group {

 		config {
 			layout {
-				tpi: 135
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
@@ -382,7 +382,7 @@ option_group {

 		config {
 			layout {
-				tpi: 135
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
--- a/src/formats/icl30.textpb
+++ b/src/formats/icl30.textpb
@@ -15,7 +15,7 @@ image_writer {
 }

 layout {
-	tpi: 48
+	format_type: FORMATTYPE_40TRACK
 	tracks: 35
 	sides: 2
 	layoutdata {
--- a/src/formats/mac.textpb
+++ b/src/formats/mac.textpb
@@ -70,7 +70,7 @@ image_writer {
 }

 layout {
-	tpi: 135
+	format_type: FORMATTYPE_80TRACK
 	tracks: 80
 	sides: 2
 	layoutdata {
--- a/src/formats/micropolis.textpb
+++ b/src/formats/micropolis.textpb
@@ -142,7 +142,7 @@ option_group {
 		
 		config {
 			layout {
-				tpi: 50
+				format_type: FORMATTYPE_40TRACK
 				tracks: 35
 				sides: 1
 			}
@@ -156,7 +156,7 @@ option_group {
 		
 		config {
 			layout {
-				tpi: 50
+				format_type: FORMATTYPE_40TRACK
 				tracks: 35
 				sides: 2
 			}
@@ -169,7 +169,7 @@ option_group {
 		
 		config {
 			layout {
-				tpi: 100
+				format_type: FORMATTYPE_80TRACK
 				tracks: 77
 				sides: 1
 			}
@@ -182,7 +182,7 @@ option_group {
 		
 		config {
 			layout {
-				tpi: 100
+				format_type: FORMATTYPE_80TRACK
 				tracks: 77
 				sides: 2
 			}
--- a/src/formats/ms2000.textpb
+++ b/src/formats/ms2000.textpb
@@ -41,7 +41,7 @@ image_writer {
 layout {
 	tracks: 70
 	sides: 1
-	tpi: 135
+	format_type: FORMATTYPE_80TRACK
 	layoutdata {
 		sector_size: 512
 		physical {
--- a/src/formats/mx.textpb
+++ b/src/formats/mx.textpb
@@ -83,7 +83,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 1
 			}
@@ -96,7 +96,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 2
 			}
@@ -109,7 +109,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 1
 			}
@@ -123,7 +123,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 			}
--- a/src/formats/n88basic.textpb
+++ b/src/formats/n88basic.textpb
@@ -28,7 +28,7 @@ image_writer {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 77
 	sides: 2
 	layoutdata {
--- a/src/formats/northstar.textpb
+++ b/src/formats/northstar.textpb
@@ -44,7 +44,7 @@ image_writer {
 }

 layout {
-	tpi: 48
+	format_type: FORMATTYPE_40TRACK
 	layoutdata {
 		physical {
 			start_sector: 0
--- a/src/formats/psos.textpb
+++ b/src/formats/psos.textpb
@@ -35,7 +35,7 @@ image_writer {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 80
 	sides: 2
 	order: HCS
--- a/src/formats/rolandd20.textpb
+++ b/src/formats/rolandd20.textpb
@@ -46,7 +46,7 @@ image_writer {
 }

 layout {
-	tpi: 135
+	format_type: FORMATTYPE_80TRACK
 	tracks: 78
 	sides: 1
 	layoutdata {
--- a/src/formats/rx50.textpb
+++ b/src/formats/rx50.textpb
@@ -25,7 +25,7 @@ image_writer {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 80
 	sides: 1
 	layoutdata {
--- a/src/formats/smaky6.textpb
+++ b/src/formats/smaky6.textpb
@@ -33,7 +33,7 @@ image_writer {
 }

 layout {
-	tpi: 100
+	format_type: FORMATTYPE_80TRACK
 	tracks: 77
 	sides: 1
 	layoutdata {
--- a/src/formats/tids990.textpb
+++ b/src/formats/tids990.textpb
@@ -40,7 +40,7 @@ image_writer {
 }

 layout {
-	tpi: 48
+	format_type: FORMATTYPE_80TRACK
 	tracks: 77
 	sides: 2
 	layoutdata {
--- a/src/formats/tiki.textpb
+++ b/src/formats/tiki.textpb
@@ -27,7 +27,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 1
 				layoutdata {
@@ -59,7 +59,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 1
 				layoutdata {
@@ -91,7 +91,7 @@ option_group {

 		config {
 			layout {
-				tpi: 48
+				format_type: FORMATTYPE_40TRACK
 				tracks: 40
 				sides: 2
 				layoutdata {
@@ -124,7 +124,7 @@ option_group {

 		config {
 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 80
 				sides: 2
 				layoutdata {
--- a/src/formats/victor9k.textpb
+++ b/src/formats/victor9k.textpb
@@ -59,7 +59,7 @@ image_writer {
 }

 layout {
-	tpi: 96
+	format_type: FORMATTYPE_80TRACK
 	tracks: 80
 	sides: 2
 	layoutdata {
--- a/src/formats/zilogmcz.textpb
+++ b/src/formats/zilogmcz.textpb
@@ -45,7 +45,7 @@ decoder {
 }

 layout {
-	tpi: 48
+	format_type: FORMATTYPE_40TRACK
 	tracks: 77
 	sides: 1
 	layoutdata {
--- a/src/gui/browserpanel.cc
+++ b/src/gui/browserpanel.cc
@@ -244,12 +244,12 @@ private:
                            uint32_t usedBlocks = std::stoul(
                                metadata.at(Filesystem::USED_BLOCKS));

-							if (!totalBlocks)
-								throw std::out_of_range("no disk usage data");
+                            if (!totalBlocks)
+                                throw std::out_of_range("no disk usage data");

-							diskSpaceGauge->Enable();
-							diskSpaceGauge->SetRange(totalBlocks);
-							diskSpaceGauge->SetValue(usedBlocks);
+                            diskSpaceGauge->Enable();
+                            diskSpaceGauge->SetRange(totalBlocks);
+                            diskSpaceGauge->SetValue(usedBlocks);
                        }
                        catch (const std::out_of_range& e)
                        {
--- a/src/gui/drivetypes/35_40.textpb
+++ b/src/gui/drivetypes/35_40.textpb
@@ -1,6 +0,0 @@
-comment: '3.5" 40 track 67.5tpi'
-
-drive {
-	tpi: 67.5
-}
-
--- a/src/gui/drivetypes/35_80.textpb
+++ b/src/gui/drivetypes/35_80.textpb
@@ -1,6 +0,0 @@
-comment: '3.5" 80 track 135tpi'
-
-drive {
-	tpi: 135
-}
-
--- a/src/gui/drivetypes/525_40.textpb
+++ b/src/gui/drivetypes/525_40.textpb
@@ -1,6 +0,0 @@
-comment: '5.25" 40 track 48tpi'
-
-drive {
-	tpi: 48
-}
-
--- a/src/gui/drivetypes/525_40M.textpb
+++ b/src/gui/drivetypes/525_40M.textpb
@@ -1,6 +0,0 @@
-comment: '5.25" 40 track 50tpi (Micropolis Mod-I)'
-
-drive {
-	tpi: 50
-}
-
--- a/src/gui/drivetypes/525_80.textpb
+++ b/src/gui/drivetypes/525_80.textpb
@@ -1,6 +0,0 @@
-comment: '5.25" 80 track 96tpi'
-
-drive {
-	tpi: 96
-}
-
--- a/src/gui/drivetypes/525_80M.textpb
+++ b/src/gui/drivetypes/525_80M.textpb
@@ -1,6 +0,0 @@
-comment: '5.25" 80 track 100tpi (Micropolis Mod-II)'
-
-drive {
-	tpi: 100
-}
-
--- a/src/gui/drivetypes/8_38.textpb
+++ b/src/gui/drivetypes/8_38.textpb
@@ -1,6 +0,0 @@
-comment: '8" 38 track 32tpi'
-
-drive {
-	tpi: 32
-}
-
--- a/src/gui/drivetypes/8_77.textpb
+++ b/src/gui/drivetypes/8_77.textpb
@@ -1,6 +0,0 @@
-comment: '8" 77 track 48tpi'
-
-drive {
-	tpi: 48
-}
-
--- a/src/gui/drivetypes/apple2.textpb
+++ b/src/gui/drivetypes/apple2.textpb
@@ -9,7 +9,6 @@ usb {
 drive {
    tracks: 160
    heads: 1
-    head_width: 4
-        tpi: 192
+    drive_type: DRIVETYPE_APPLE2
 }

--- a/src/gui/drivetypes/build.py
+++ b/src/gui/drivetypes/build.py
@@ -3,14 +3,8 @@ from build.c import cxxlibrary
 from scripts.build import protoencode

 drivetypes = [
-    "35_40",
-    "35_80",
-    "525_40M",
-    "525_40",
-    "525_80M",
-    "525_80",
-    "8_38",
-    "8_77",
+    "40track",
+    "80track",
    "apple2",
 ]

--- a/src/gui/icon.png.h
+++ b/src/gui/icon.png.h
--- a/src/gui/idlepanel.cc
+++ b/src/gui/idlepanel.cc
@@ -239,12 +239,12 @@ public:
            {
                if (_selectedFluxFormat)
                {
-                if (_selectedFluxFormat->sink)
-                    _selectedFluxFormat->sink(_selectedFluxFilename,
-                        globalConfig().overrides()->mutable_flux_sink());
-                if (_selectedFluxFormat->source)
-                    _selectedFluxFormat->source(_selectedFluxFilename,
-                        globalConfig().overrides()->mutable_flux_source());
+                    if (_selectedFluxFormat->sink)
+                        _selectedFluxFormat->sink(_selectedFluxFilename,
+                            globalConfig().overrides()->mutable_flux_sink());
+                    if (_selectedFluxFormat->source)
+                        _selectedFluxFormat->source(_selectedFluxFilename,
+                            globalConfig().overrides()->mutable_flux_source());
                }
                break;
            }
--- a/src/gui/layout.h
+++ b/src/gui/layout.h
--- a/src/gui/main.cc
+++ b/src/gui/main.cc
@@ -53,19 +53,19 @@ private:

 bool FluxEngineApp::OnInit()
 {
-	try
-	{
-    wxImage::AddHandler(new wxPNGHandler());
-    Bind(EXEC_EVENT_TYPE, &FluxEngineApp::OnExec, this);
-    _mainWindow = CreateMainWindow();
-    _mainWindow->Show(true);
-    return true;
-	}
-	catch (const ErrorException* e)
-	{
-		fmt::print(stderr, "Exception on startup: {}\n", e->message);
-		exit(1);
-	}
+    try
+    {
+        wxImage::AddHandler(new wxPNGHandler());
+        Bind(EXEC_EVENT_TYPE, &FluxEngineApp::OnExec, this);
+        _mainWindow = CreateMainWindow();
+        _mainWindow->Show(true);
+        return true;
+    }
+    catch (const ErrorException* e)
+    {
+        fmt::print(stderr, "Exception on startup: {}\n", e->message);
+        exit(1);
+    }
 }

 wxThread::ExitCode FluxEngineApp::Entry()
--- a/tests/configs.cc
+++ b/tests/configs.cc
@@ -83,8 +83,8 @@ static void validateConfigWithOptions(std::string baseConfigName,
 {
    /* All configs must have a tpi. */

-    if (!config.layout().has_tpi())
-        configError("{}{}: no layout.tpi set", baseConfigName, options);
+    if (!config.layout().has_format_type())
+        configError("{}{}: no layout.format_type set", baseConfigName, options);
 }

 static void validateToplevelConfig(std::string name)
--- a/tests/cpmfs.cc
+++ b/tests/cpmfs.cc
@@ -119,11 +119,11 @@ int main(void)
    {
        const std::string text = R"M(
 			drive {
-				tpi: 96
+				drive_type: DRIVETYPE_80TRACK
 			}

 			layout {
-				tpi: 96
+				format_type: FORMATTYPE_80TRACK
 				tracks: 10
 				sides: 1
 				layoutdata {
--- a/tests/layout.cc
+++ b/tests/layout.cc
@@ -22,11 +22,11 @@ static void test_physical_sectors()
    globalConfig().clear();
    globalConfig().readBaseConfig(R"M(
 		drive {
-			tpi: 96
+			drive_type: DRIVETYPE_80TRACK
 		}

 		layout {
-			tpi: 96
+			format_type: FORMATTYPE_80TRACK
 			tracks: 78
 			sides: 2
 			layoutdata {
@@ -55,11 +55,11 @@ static void test_logical_sectors()
    globalConfig().clear();
    globalConfig().readBaseConfig(R"M(
 		drive {
-			tpi: 96
+			drive_type: DRIVETYPE_80TRACK
 		}

 		layout {
-			tpi: 96
+			format_type: FORMATTYPE_80TRACK
 			tracks: 78
 			sides: 2
 			layoutdata {
@@ -94,11 +94,11 @@ static void test_both_sectors()
    globalConfig().clear();
    globalConfig().readBaseConfig(R"M(
 		drive {
-			tpi: 96
+			drive_type: DRIVETYPE_80TRACK
 		}

 		layout {
-			tpi: 96
+			format_type: FORMATTYPE_80TRACK
 			tracks: 78
 			sides: 2
 			layoutdata {
@@ -133,11 +133,11 @@ static void test_skew()
    globalConfig().clear();
    globalConfig().readBaseConfig(R"M(
 		drive {
-			tpi: 96
+			drive_type: DRIVETYPE_80TRACK
 		}

 		layout {
-			tpi: 96
+			format_type: FORMATTYPE_80TRACK
 			tracks: 78
 			sides: 2
 			layoutdata {
--- a/tests/options.cc
+++ b/tests/options.cc
@@ -23,15 +23,15 @@ static void test_option_validity()
    globalConfig().clear();
    globalConfig().readBaseConfig(R"M(
 		drive {
-			tpi: 96
+			drive_type: DRIVETYPE_80TRACK
 		}

        option {
            name: "option1"

            prerequisite: {
-                key: "drive.tpi"
-                value: "96"
+                key: "drive.drive_type"
+                value: "DRIVETYPE_80TRACK"
            }
        }

@@ -39,8 +39,8 @@ static void test_option_validity()
            name: "option2"

            prerequisite: {
-                key: "drive.tpi"
-                value: "95"
+                key: "drive.drive_type"
+                value: "DRIVETYPE_40TRACK"
            }
        }

@@ -48,8 +48,8 @@ static void test_option_validity()
            name: "option3"

            prerequisite: {
-                key: "drive.tpi"
-                value: ["0", "96"]
+                key: "drive.drive_type"
+                value: ["DRIVETYPE_UNKNOWN", "DRIVETYPE_80TRACK"]
            }
        }
 	)M");