Separate out headers for structures

hdr/bios.asm

@@ -0,0 +1,17 @@
+; Labels for BIOS entry points
+BOOT:   EQU (BIOS+0)
+WBOOT:  EQU (BIOS+3)
+CONST:  EQU (BIOS+6)
+CONIN:  EQU (BIOS+9)
+CONOUT: EQU (BIOS+12)
+LIST:   EQU (BIOS+15)
+PUNCH:  EQU (BIOS+18)
+READER: EQU (BIOS+21)
+HOME:   EQU (BIOS+24)
+SELDSK: EQU (BIOS+27)
+SETTRK: EQU (BIOS+30)
+SETSEC: EQU (BIOS+33)
+SETDMA: EQU (BIOS+36)
+READ:   EQU (BIOS+39)
+WRITE:  EQU (BIOS+42)
+LISTST: EQU (BIOS+45)

hdr/bpb.asm

@@ -0,0 +1,12 @@
+; BPB from first sector on FAT fs, starting 0x0B
+BPB_SS:  EQU 0  ; WORD sector size
+BPB_SC:  EQU 2  ; BYTE sectors per cluster
+BPB_RSC: EQU 3  ; WORD reserved sector count
+BPB_FN:  EQU 5  ; BYTE number of FATs
+BPB_RDE: EQU 6  ; WORD number of root directory entries
+BPB_TS:  EQU 8  ; WORD total number of sectors
+BPB_MI:  EQU 10 ; BYTE medium identifier
+BPB_SF:  EQU 11 ; WORD sectors per FAT
+BPB_SPT: EQU 13 ; WORD sectors per track
+BPB_NOS: EQU 15 ; WORD number of sides/heads
+BPB_PO:  EQU 17 ; DWORD partition offset

hdr/fcb.asm

@@ -0,0 +1,10 @@
+; File control block
+FCB_DRV: EQU 0  ; BYTE 0=A: 1=B: 2=C: ...
+FCB_NAM: EQU 1  ; 8 BYTES, space padded
+FCB_EXT: EQU 9  ; 3 BYTES, space padded
+FCB_TYP: EQU 12 ; BYTE FCB type
+; TYP=1: regular file
+FCB_BLK: EQU 13 ; current 128b block in sector
+FCB_CLU: EQU 14 ; current sector
+FCB_LFT: EQU 16 ; bytes left to read in current file
+FCB_END: EQU 20 ; FCB length