Changes

Graduate Software

73 bytes added, 16:03, 28 April 2018
/* Notes */
;; HL = address of directory entry
;; A = rom number
0070 3f70 32be3f ld (3fbeh),a ;; ROM number store to RAM 0073 3f73 e5 push hl 0074 3f74 dde1 pop ix 0076 3f76 2afefb ld hl,(0fbfeh) 0079 3f79 113400 ld de,0034h 007c 3f7c 19 add hl,de 007d 3f7d 118c3f ld de,3f8ch ;; address to call to load file from ROM 0080 3f80 73 ld (hl),e 0081 3f81 23 inc hl 0082 3f82 72 ld (hl),d 0083 3f83 2afefb ld hl,(0fbfeh) 0086 3f86 111000 ld de,0010h 0089 3f89 0e3b ld c,3bh 008b 3f8b e9 jp (hl)
008c ;; load file from ROM into RAM 3f8c dd6e00 ld l,(ix+00h) ;; load address 008f 3f8f dd6601 ld h,(ix+01h) 0092 3f92 dd4e02 ld c,(ix+02h) ;; length 0095 3f95 dd4603 ld b,(ix+03h) 0098 3f98 110001 ld de,0100h ;; load address for .COM file 009b 3f9b cdbf3f call 3fbfh ;; read byte from rom 009e 3f9e 12 ld (de),a ;; write to memory 009f 3f9f 13 inc de 00a0 3fa0 23 inc hl 00a1 3fa1 0b dec bc 00a2 3fa2 79 ld a,c 00a3 3fa3 b0 or b 00a4 3fa4 20f5 jr nz,009bh
00a6 3fa6 1eff ld e,0ffh ;; error code in H 00a8 3fa8 0e2d ld c,2dh ;; F_ERRMODE - set action on hardware error 00aa 3faa cd0500 call 0005h ;; call BDOS 00ad 3fad 3aaffb ld a,(0fbafh) 00b0 3fb0 5f ld e,a 00b1 3fb1 0e0e ld c,0eh ;; select disc 00b3 3fb3 cd0500 call 0005h ;; call BDOS 00b6 3fb6 1e00 ld e,00h 00b8 3fb8 0e2d ld c,2dh ;; F_ERRMODE - set action on hardware error 00ba 3fba cd0500 call 0005h;; call BDOS 00bd 3fbd c9 ret
00be 3fbe 00 nop ;; storage for ROM number
;; read byte from ROM
00bf 3fbf c5 push bc 00c0 3fc0 3abe3f ld a,(3fbeh) 00c3 3fc3 4f ld c,a 00c4 3fc4 cdc93f call 3fc9h 00c7 3fc7 c1 pop bc 00c8 3fc8 c9 ret
;; HL = address to read from ROM
;; C = rom number
;; BC' = 7F80 port number
00c9 3fc9 f3 di 00ca 3fca c5 push bc 00cb 3fcb d9 exx 00cc 3fcc cb99 res 3,c ;; enable upper rom 00ce 3fce ed49 out (c),c 00d0 3fd0 d9 exx 00d1 3fd1 06df ld b,0dfh ;; select ROM 00d3 3fd3 ed49 out (c),c 00d5 3fd5 7e ld a,(hl) ;; read byte from ROM 00d6 3fd6 d9 exx 00d7 3fd7 cbd9 set 3,c ;; disable upper rom 00d9 3fd9 ed49 out (c),c 00db 3fdb d9 exx 00dc 3fdc fb ei 00dd 3fdd c1 pop bc 00de 3fde c9 ret
;; used?
;; BC = 7F8x with bit 3 clear. bits 1,0 are mode.
;; HL = address to read from ROM
00df 3fdf ed49 out (c),c ;; must enable ROM 00e1 3fe1 d9 exx 00e2 3fe2 06df ld b,0dfh ;; select ROM 00e4 3fe4 ed49 out (c),c 00e6 3fe6 7e ld a,(hl) ;; read from rom 00e7 3fe7 d9 exx 00e8 3fe8 cbd9 set 3,c ;; disable ROM again 00ea 3fea ed49 out (c),c 00ec 3fec d9 exx 00ed 3fed fb ei 00ee 3fee c1 pop bc 00ef 3fef c9 ret
3. Up to 16 files can be defined. Each file takes 1 entry. Unused entries are filled with &FF.
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