src/components/DiskInfo.vue

@@ -1,18 +1,20 @@
 <script lang="ts" setup>
 import { computed } from 'vue'
-import { FloppyDisk } from '@/floppy/disk.ts'
+import { getBiosParameterBlock } from '@/floppy/disk.ts'
+import PropertyList from '@/components/PropertyList.vue'
 
 const { data = new ArrayBuffer(0) } = defineProps<{ data: ArrayBuffer }>()
 
-const floppyDisk = computed(() => {
-  return new FloppyDisk(data)
+const biosParameterBlock = computed(() => {
+  return getBiosParameterBlock(data)
 })
 </script>
 
 <template>
-  <section v-if="floppyDisk.bootSectorInfo">
-    <h3>Boot Sector</h3>
-    <pre>{{ floppyDisk.bootSectorInfo }}</pre>
+  <section v-if="biosParameterBlock">
+    <h3>BIOS Parameter Block (BPB)</h3>
+    <PropertyList :obj="biosParameterBlock" />
+    <pre>{{ biosParameterBlock }}</pre>
   </section>
 </template>
 

src/components/HexDump.vue

@@ -14,12 +14,8 @@ const hexDump = computed(() => {
     return ''.padEnd(80, ' ')
   }
 
-  let lastLine = ''
-  let repeat = false
-
   while (offset < total) {
-    const offsetStr = offset.toString(16).padStart(8, '0')
-    const values = []
+    const values = [offset.toString(16).padStart(8, '0')]
     const asciiValues: string[] = []
     let cnt = 0
     while (offset < total && cnt < 16) {
@@ -35,7 +31,7 @@ const hexDump = computed(() => {
       values.push(byte.toString(16).padStart(2, '0'))
 
       const char = String.fromCharCode(byte)
-      if (char >= ' ' && char <= '~') {
+      if (char > ' ' && char <= 'a') {
         asciiValues.push(char)
       } else {
         asciiValues.push('.')
@@ -64,21 +60,7 @@ const hexDump = computed(() => {
       asciiValues.push('|')
     }
 
-    const line = values.join(' ')
-    if (line !== lastLine) {
-      if (repeat) {
-        lines.push('*'.padEnd(80, ' '))
-      }
-      repeat = false
-
-      lines.push([offsetStr, line].join(' ') + asciiValues.join(''))
-      lastLine = line
-    } else {
-      repeat = true
-    }
-  }
-  if (repeat) {
-    lines.push('*'.padEnd(80, ' '))
+    lines.push(values.join(' ') + asciiValues.join(''))
   }
   lines.push(offset.toString(16).padStart(8, '0').padEnd(80, ' '))
   return lines.join('\n')
@@ -94,7 +76,7 @@ pre {
   width: fit-content;
   padding: 0.5em 1em 10em;
   box-sizing: border-box;
-  overflow-y: scroll;
+  overflow: scroll;
   min-height: 10rem;
   height: 20rem;
   max-height: 20rem;

src/floppy/disk.ts

@@ -1,121 +1,61 @@
-export interface IBootSectorInfo {
-  jumpInstruction: [number, number, number]
-  oemName: string
-  biosParameterBlock: IBiosParameterBlock
-  extendedBootSector: IExtendedBootSectorSmall
-  bootPartitionSignature: number
-}
-
-export interface IExtendedBootSectorSmall {
-  driveNumber: number
-  reserved: number
-  bootSignature: number
-  volumeId?: number
-  volumeLabel?: string
-  fileSystemType?: string
-}
-
-export interface IBiosParameterBlock {
+export interface BiosParameterBlock {
+  oemId: string
   bytesPerSector: number
   sectorsPerCluster: number
-  reservedSectorCount: number
-  tableCount: number
-  rootEntryCount: number
-  totalSectorsSmall: number
-  mediaDescriptorType: number
-  sectorsPerTableSmall: number
+  numReservedSectors: number
+  numFATs: number
+  numRootDirEntries: number
+  totalSectors: number
+  mediaTypeDescriptor: number
+  sectorsPerFAT: number
   sectorsPerTrack: number
-  headCount: number
-  hiddenSectorCount: number
-  totalSectorsLarge: number
+  numHeads: number
+  bootSignature: number
+  volumeId: number
+  volumeLabel: string
+  fileSystemId: string
 }
 
-export class FloppyDisk {
-  private readonly _buffer = new ArrayBuffer(0)
-  private _bootSector: IBootSectorInfo | null = null
-
-  constructor(buffer: ArrayBuffer) {
-    this._buffer = buffer
-  }
-
-  get bootSectorInfo() {
-    return (this._bootSector = this._bootSector ?? decodeBootSector(this._buffer))
-  }
-}
-
-function decodeBootSector(buffer: ArrayBuffer): IBootSectorInfo | null {
-  if (buffer.byteLength < 512) {
+export function getBiosParameterBlock(buffer: ArrayBuffer): BiosParameterBlock | null {
+  if (buffer.byteLength < 64) {
     return null
   }
 
-  const asciiDecoder = new TextDecoder('ascii')
   const data = new DataView(buffer)
 
-  const jumpInstruction: [number, number, number] = [
-    data.getUint8(0),
-    data.getUint8(1),
-    data.getUint8(2),
-  ]
+  const asciiDecoder = new TextDecoder('ascii')
 
-  const oemName = asciiDecoder.decode(buffer.slice(3, 11))
+  const oemId = asciiDecoder.decode(buffer.slice(3, 11))
   const bytesPerSector = data.getUint16(11, true)
   const sectorsPerCluster = data.getUint8(13)
-  const reservedSectorCount = data.getUint16(14, true)
-  const tableCount = data.getUint8(16)
-  const rootEntryCount = data.getUint16(17, true)
-  const totalSectorsSmall = data.getUint16(19, true)
-  const mediaDescriptorType = data.getUint8(21)
-  const sectorsPerTableSmall = data.getUint16(22, true)
+  const numReservedSectors = data.getUint16(14, true)
+  const numFATs = data.getUint8(16)
+  const numRootDirEntries = data.getUint16(17, true)
+  const totalSectors = data.getUint16(19, true)
+  const mediaTypeDescriptor = data.getUint8(21)
+  const sectorsPerFAT = data.getUint16(22, true)
   const sectorsPerTrack = data.getUint16(24, true)
-  const headCount = data.getUint16(26, true)
-  const hiddenSectorCount = data.getUint32(28, true)
-  const totalSectorsLarge = data.getUint32(32, true)
-  const driveNumber = data.getUint8(36)
-  const reserved = data.getUint8(37)
+  const numHeads = data.getUint16(26, true)
   const bootSignature = data.getUint8(38)
-
-  let volumeId
-  if (bootSignature === 0x28 || bootSignature === 0x29) {
-    volumeId = data.getUint32(39, true)
-  }
-
-  let volumeLabel
-  if (bootSignature === 0x29) {
-    volumeLabel = asciiDecoder.decode(buffer.slice(43, 54))
-  }
-
-  let fileSystemType
-  if (bootSignature === 0x29) {
-    fileSystemType = asciiDecoder.decode(buffer.slice(54, 62))
-  }
-
-  const bootPartitionSignature = data.getUint16(510, true)
+  const volumeId = data.getUint32(39, true)
+  const volumeLabel = asciiDecoder.decode(buffer.slice(43, 54))
+  const fileSystemId = asciiDecoder.decode(buffer.slice(54, 62))
 
   return {
-    jumpInstruction,
-    oemName,
-    bootPartitionSignature,
-    biosParameterBlock: {
+    oemId,
     bytesPerSector,
     sectorsPerCluster,
-      reservedSectorCount,
-      tableCount,
-      rootEntryCount,
-      totalSectorsSmall,
-      mediaDescriptorType,
-      sectorsPerTableSmall,
+    numReservedSectors,
+    numFATs,
+    numRootDirEntries,
+    totalSectors,
+    mediaTypeDescriptor,
+    sectorsPerFAT,
     sectorsPerTrack,
-      headCount,
-      hiddenSectorCount,
-      totalSectorsLarge,
-    },
-    extendedBootSector: {
-      driveNumber,
-      reserved,
+    numHeads,
     bootSignature,
     volumeId,
     volumeLabel,
-      fileSystemType,
-    },
+    fileSystemId,
   }
 }