prog8/compiler/res/prog8lib/cx16/cx16diskio.p8

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; Cx16 specific disk drive I/O routines.
%import diskio
cx16diskio {
; Use kernal LOAD routine to load the given program file in memory.
2022-01-03 21:44:27 +00:00
; This is similar to Basic's LOAD "filename",drive / LOAD "filename",drive,1
; If you don't give an address_override, the location in memory is taken from the 2-byte file header.
; If you specify a custom address_override, the first 2 bytes in the file are ignored
; and the rest is loaded at the given location in memory.
; Returns the end load address+1 if successful or 0 if a load error occurred.
; You can use the load_size() function to calcuate the size of the file that was loaded.
sub load(ubyte drivenumber, uword filenameptr, ubyte bank, uword address_override) -> uword {
cx16.rambank(bank)
return diskio.load(drivenumber, filenameptr, address_override)
}
; Use kernal LOAD routine to load the given file in memory.
; INCLUDING the first 2 bytes in the file: no program header is assumed in the file.
; The load address is mandatory. Returns the number of bytes loaded.
; If you load into regular system ram, use cx16.getrambank() for the bank argument,
; or alternatively make sure to reset the correct ram bank yourself after the load!
; Returns the end load address+1 if successful or 0 if a load error occurred.
; You can use the load_size() function to calcuate the size of the file that was loaded.
sub load_raw(ubyte drivenumber, uword filenameptr, ubyte bank, uword address) -> uword {
cx16.rambank(bank)
return diskio.load_headerless_cx16(drivenumber, filenameptr, address, true)
}
; For use directly after a load or load_raw call (don't mess with the ram bank yet):
; Calculates the number of bytes loaded (files > 64Kb ar truncated to 16 bits)
sub load_size(ubyte startbank, uword startaddress, uword endaddress) -> uword {
return $2000 * (cx16.getrambank() - startbank) + endaddress - startaddress
}
asmsub vload(str name @R0, ubyte device @Y, ubyte bank @A, uword address @R1) -> ubyte @A {
; -- like the basic command VLOAD "filename",device,bank,address
; loads a file into Vera's video memory in the given bank:address, returns success in A
%asm {{
; -- load a file into video ram
phx
pha
tya
tax
lda #1
ldy #0
jsr c64.SETLFS
lda cx16.r0
ldy cx16.r0+1
jsr prog8_lib.strlen
tya
ldx cx16.r0
ldy cx16.r0+1
jsr c64.SETNAM
pla
clc
adc #2
ldx cx16.r1
ldy cx16.r1+1
stz P8ZP_SCRATCH_B1
jsr c64.LOAD
bcs +
inc P8ZP_SCRATCH_B1
+ jsr c64.CLRCHN
lda #1
jsr c64.CLOSE
plx
lda P8ZP_SCRATCH_B1
rts
}}
}
; replacement function that makes use of fast block read capability of the X16
; use this in place of regular diskio.f_read()
sub f_read(uword bufferpointer, uword num_bytes) -> uword {
; -- read from the currently open file, up to the given number of bytes.
; returns the actual number of bytes read. (checks for End-of-file and error conditions)
if not diskio.iteration_in_progress or not num_bytes
return 0
diskio.list_blocks = 0 ; we reuse this variable for the total number of bytes read
if diskio.have_first_byte {
diskio.have_first_byte=false
@(bufferpointer) = diskio.first_byte
bufferpointer++
diskio.list_blocks++
num_bytes--
}
void c64.CHKIN(11) ; use #11 as input channel again
; commander X16 supports fast block-read via macptr() kernal call
uword size
while num_bytes {
size = 255
if num_bytes<size
size = num_bytes
size = cx16.macptr(lsb(size), bufferpointer)
if_cs
goto byte_read_loop ; macptr block read not supported, do fallback loop
diskio.list_blocks += size
bufferpointer += size
if msb(bufferpointer) == $c0
bufferpointer = mkword($a0, lsb(bufferpointer)) ; wrap over bank boundary
num_bytes -= size
if c64.READST() & $40 {
diskio.f_close() ; end of file, close it
break
}
}
return diskio.list_blocks ; number of bytes read
byte_read_loop: ; fallback if macptr() isn't supported on the device
%asm {{
lda bufferpointer
sta m_in_buffer+1
lda bufferpointer+1
sta m_in_buffer+2
}}
repeat num_bytes {
%asm {{
jsr c64.CHRIN
sta cx16.r5
m_in_buffer sta $ffff
inc m_in_buffer+1
bne +
inc m_in_buffer+2
+ inc diskio.list_blocks
bne +
inc diskio.list_blocks+1
+
}}
if cx16.r5==$0d { ; chance on I/o error status?
diskio.first_byte = c64.READST()
if diskio.first_byte & $40 {
diskio.f_close() ; end of file, close it
diskio.list_blocks-- ; don't count that last CHRIN read
}
if diskio.first_byte
return diskio.list_blocks ; number of bytes read
}
}
return diskio.list_blocks ; number of bytes read
}
; replacement function that makes use of fast block read capability of the X16
; use this in place of regular diskio.f_read_all()
sub f_read_all(uword bufferpointer) -> uword {
; -- read the full contents of the file, returns number of bytes read.
if not diskio.iteration_in_progress
return 0
uword total_read = 0
if diskio.have_first_byte {
diskio.have_first_byte=false
@(bufferpointer) = diskio.first_byte
bufferpointer++
total_read = 1
}
while not c64.READST() {
uword size = cx16diskio.f_read(bufferpointer, 256)
total_read += size
bufferpointer += size
}
return total_read
}
}