adapted to Kick Assembler, some documentation update
This commit is contained in:
FeralChild64 committed
1 parent
ae23dbae7b
commit
de27124b4f
198 files changed
+4181
-3976
No files matched your search
@@ -1,22 +1,22 @@
|
||||
|
||||
;;
|
||||
;; Checks whether device number (in .A) is a correct IEC device number
|
||||
;;
|
||||
;; Preserves .A, .X and .Y
|
||||
;;
|
||||
//
|
||||
// Checks whether device number (in .A) is a correct IEC device number
|
||||
//
|
||||
// Preserves .A, .X and .Y
|
||||
//
|
||||
|
||||
iec_check_devnum:
|
||||
;; 0, 1, 2, or 3 are illegal - reserved for non-IEC devices on Commodore
|
||||
// 0, 1, 2, or 3 are illegal - reserved for non-IEC devices on Commodore
|
||||
cmp #$04
|
||||
bcs +
|
||||
;; FALLTROUGH
|
||||
bcs !+
|
||||
// FALLTROUGH
|
||||
iec_check_devnum_failed:
|
||||
sec ; indicate non-IEC device
|
||||
sec // indicate non-IEC device
|
||||
rts
|
||||
*
|
||||
;; 31 and above are illegal too, due to IEC command encoding scheme,
|
||||
;; see https://www.pagetable.com/?p=1031
|
||||
!:
|
||||
// 31 and above are illegal too, due to IEC command encoding scheme,
|
||||
// see https://www.pagetable.com/?p=1031
|
||||
cmp #$1F
|
||||
bcs iec_check_devnum_failed
|
||||
;; Carry is clear here - indicates IEC device
|
||||
// Carry is clear here - indicates IEC device
|
||||
rts
|
||||
@@ -1,16 +1,16 @@
|
||||
|
||||
;;
|
||||
;; Kernal internal IEC routine
|
||||
;;
|
||||
;; - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
|
||||
;;
|
||||
//
|
||||
// Kernal internal IEC routine
|
||||
//
|
||||
// - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
|
||||
//
|
||||
|
||||
iec_cmd_close:
|
||||
|
||||
jsr iec_check_channel_openclose
|
||||
bcc +
|
||||
bcc !+
|
||||
jmp kernalerror_FILE_NOT_INPUT
|
||||
*
|
||||
!:
|
||||
ora #$E0
|
||||
|
||||
jmp common_open_close_unlsn_second
|
||||
@@ -1,42 +1,42 @@
|
||||
|
||||
;;
|
||||
;; Kernal internal IEC routine
|
||||
;;
|
||||
;; - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
|
||||
;;
|
||||
//
|
||||
// Kernal internal IEC routine
|
||||
//
|
||||
// - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
|
||||
//
|
||||
|
||||
|
||||
iec_cmd_open: ; similar to TKSA, but without turnaround
|
||||
iec_cmd_open: // similar to TKSA, but without turnaround
|
||||
|
||||
jsr iec_check_channel_openclose
|
||||
bcc +
|
||||
bcc !+
|
||||
jmp kernalerror_FILE_NOT_INPUT
|
||||
*
|
||||
!:
|
||||
ora #$F0
|
||||
|
||||
;; FALLTROUGH
|
||||
// FALLTROUGH
|
||||
|
||||
common_open_close_unlsn_second: ; common part of several commands
|
||||
common_open_close_unlsn_second: // common part of several commands
|
||||
|
||||
sta IEC_TMP2
|
||||
jsr iec_tx_command
|
||||
bcs + ; branch if error
|
||||
bcs !+ // branch if error
|
||||
jmp iec_tx_command_finalize
|
||||
*
|
||||
!:
|
||||
rts
|
||||
|
||||
iec_check_channel_openclose:
|
||||
;; Due to OPEN/CLOSE/TKSA/SECOND command encoding (see https://www.pagetable.com/?p=1031),
|
||||
;; allowed channels are 0-15; report error if out of range
|
||||
// Due to OPEN/CLOSE/TKSA/SECOND command encoding (see https://www.pagetable.com/?p=1031),
|
||||
// allowed channels are 0-15; report error if out of range
|
||||
cmp #$10
|
||||
bcc +
|
||||
;; Workaround to allow reading executable files and disk directory
|
||||
;; using OPEN routine - see https://www.pagetable.com/?p=273 for
|
||||
;; example usage
|
||||
bcc !+
|
||||
// Workaround to allow reading executable files and disk directory
|
||||
// using OPEN routine - see https://www.pagetable.com/?p=273 for
|
||||
// example usage
|
||||
cmp #$60
|
||||
beq +
|
||||
sec ; mark unsuitable channel number
|
||||
beq !+
|
||||
sec // mark unsuitable channel number
|
||||
rts
|
||||
*
|
||||
clc ; mark suitable channel number
|
||||
!:
|
||||
clc // mark suitable channel number
|
||||
rts
|
||||
@@ -1,15 +1,15 @@
|
||||
|
||||
iec_pull_atn_clk_release_data:
|
||||
|
||||
;; Pulled CLK = DATA considered invalid; for extra robustness on non-emulated
|
||||
;; hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// Pulled CLK = DATA considered invalid; for extra robustness on non-emulated
|
||||
// hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
// http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
|
||||
lda CIA2_PRA
|
||||
ora #BIT_CIA2_PRA_ATN_OUT ; pull
|
||||
ora #BIT_CIA2_PRA_ATN_OUT // pull
|
||||
sta CIA2_PRA
|
||||
ora #BIT_CIA2_PRA_CLK_OUT ; pull
|
||||
ora #BIT_CIA2_PRA_CLK_OUT // pull
|
||||
sta CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
@@ -1,13 +1,13 @@
|
||||
|
||||
iec_pull_clk_release_data:
|
||||
|
||||
;; Pulled CLK = DATA considered invalid; for extra robustness on non-emulated
|
||||
;; hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// Pulled CLK = DATA considered invalid; for extra robustness on non-emulated
|
||||
// hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
// http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
|
||||
lda CIA2_PRA
|
||||
ora #BIT_CIA2_PRA_CLK_OUT ; pull
|
||||
ora #BIT_CIA2_PRA_CLK_OUT // pull
|
||||
sta CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
@@ -2,7 +2,7 @@
|
||||
iec_pull_clk_release_data_oneshot:
|
||||
|
||||
lda CIA2_PRA
|
||||
ora #BIT_CIA2_PRA_CLK_OUT ; pull
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT ; release
|
||||
ora #BIT_CIA2_PRA_CLK_OUT // pull
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
@@ -1,15 +1,15 @@
|
||||
|
||||
iec_pull_data_release_atn_clk:
|
||||
|
||||
;; Released CLK = DATA considered valid; for extra robustness on non-emulated
|
||||
;; hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// Released CLK = DATA considered valid; for extra robustness on non-emulated
|
||||
// hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
// http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
|
||||
lda CIA2_PRA
|
||||
ora #BIT_CIA2_PRA_DAT_OUT ; pull
|
||||
ora #BIT_CIA2_PRA_DAT_OUT // pull
|
||||
sta CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_CLK_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_CLK_OUT // release
|
||||
sta CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_ATN_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_ATN_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
@@ -2,7 +2,7 @@
|
||||
iec_release_atn:
|
||||
|
||||
lda CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_ATN_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_ATN_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
|
||||
@@ -1,16 +1,16 @@
|
||||
|
||||
iec_release_atn_clk_data:
|
||||
|
||||
;; Released CLK = DATA considered valid; for extra robustness on non-emulated
|
||||
;; hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// Released CLK = DATA considered valid; for extra robustness on non-emulated
|
||||
// hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
// http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
|
||||
lda CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_ATN_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_ATN_OUT // release
|
||||
sta CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT // release
|
||||
sta CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_CLK_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_CLK_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
|
||||
@@ -1,13 +1,13 @@
|
||||
|
||||
iec_release_clk_data:
|
||||
|
||||
;; Released CLK = DATA considered valid; for extra robustness on non-emulated
|
||||
;; hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// Released CLK = DATA considered valid; for extra robustness on non-emulated
|
||||
// hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
// http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
|
||||
lda CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT // release
|
||||
sta CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_CLK_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_CLK_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
@@ -1,13 +1,13 @@
|
||||
|
||||
iec_release_clk_pull_data:
|
||||
|
||||
;; Released CLK = DATA considered valid; for extra robustness on non-emulated
|
||||
;; hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// Released CLK = DATA considered valid; for extra robustness on non-emulated
|
||||
// hardware give some lines few more cycles to stabilize; see page 10 of
|
||||
// http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
|
||||
lda CIA2_PRA
|
||||
ora #BIT_CIA2_PRA_DAT_OUT ; pull
|
||||
ora #BIT_CIA2_PRA_DAT_OUT // pull
|
||||
sta CIA2_PRA
|
||||
and #$FF - BIT_CIA2_PRA_CLK_OUT ; release
|
||||
and #$FF - BIT_CIA2_PRA_CLK_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
+15
-15
@@ -1,38 +1,38 @@
|
||||
|
||||
;;
|
||||
;; Helper routines to return with error/success
|
||||
;;
|
||||
;; All of them restore X/Y registers from stack,
|
||||
;; they take care about Carry flag,
|
||||
;; error return reeset IEC line to default state,
|
||||
;; take care about .A and IOSTATUS
|
||||
;;
|
||||
//
|
||||
// Helper routines to return with error/success
|
||||
//
|
||||
// All of them restore X/Y registers from stack,
|
||||
// they take care about Carry flag,
|
||||
// error return reeset IEC line to default state,
|
||||
// take care about .A and IOSTATUS
|
||||
//
|
||||
|
||||
iec_return_success:
|
||||
|
||||
;; BSOUR is certainly not valid anymore
|
||||
// BSOUR is certainly not valid anymore
|
||||
lda #$00
|
||||
sta C3PO
|
||||
;; Restore registers
|
||||
// Restore registers
|
||||
pla
|
||||
tay
|
||||
pla
|
||||
tax
|
||||
;; Report success
|
||||
// Report success
|
||||
clc
|
||||
rts
|
||||
|
||||
iec_return_DEVICE_NOT_FOUND:
|
||||
|
||||
;; Set IEC line to normal idle state
|
||||
// Set IEC line to normal idle state
|
||||
jsr iec_set_idle
|
||||
;; BSOUR is certainly not valid anymore
|
||||
// BSOUR is certainly not valid anymore
|
||||
lda #$00
|
||||
sta C3PO
|
||||
;; Restore registers
|
||||
// Restore registers
|
||||
pla
|
||||
tay
|
||||
pla
|
||||
tax
|
||||
;; Report error
|
||||
// Report error
|
||||
jmp kernalerror_DEVICE_NOT_FOUND
|
||||
@@ -1,141 +1,141 @@
|
||||
;; Receive a byte from the IEC bus.
|
||||
;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc,
|
||||
;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf (page 11)
|
||||
;;
|
||||
;; Preserves .X and .Y registers
|
||||
// Receive a byte from the IEC bus.
|
||||
// Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc,
|
||||
// http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf (page 11)
|
||||
//
|
||||
// Preserves .X and .Y registers
|
||||
|
||||
iec_rx_byte:
|
||||
|
||||
;; Store .X and .Y on the stack - preserve them
|
||||
// Store .X and .Y on the stack - preserve them
|
||||
txa
|
||||
pha
|
||||
tya
|
||||
pha
|
||||
|
||||
;; Timing is critical here - execute on disabled IRQs
|
||||
// Timing is critical here - execute on disabled IRQs
|
||||
php
|
||||
sei
|
||||
|
||||
;; First, we wait for the talker to release the CLK line
|
||||
// First, we wait for the talker to release the CLK line
|
||||
jsr iec_wait_for_clk_release
|
||||
|
||||
;; We then release the DATA to signal we are ready
|
||||
;; We can use this routine, since we weren't pulling CLK anyway
|
||||
// We then release the DATA to signal we are ready
|
||||
// We can use this routine, since we weren't pulling CLK anyway
|
||||
jsr iec_release_clk_data
|
||||
|
||||
;; Wait till data line is released (someone else might be holding it)
|
||||
// Wait till data line is released (someone else might be holding it)
|
||||
jsr iec_wait_for_data_release
|
||||
|
||||
;; Wait for talker to pull CLK.
|
||||
;; If over 200 usec (205 cycles on NTSC machine) , then it is EOI.
|
||||
;; Loop iteraction takes 13 cycles, 17 full iterations are enough
|
||||
// Wait for talker to pull CLK.
|
||||
// If over 200 usec (205 cycles on NTSC machine) , then it is EOI.
|
||||
// Loop iteraction takes 13 cycles, 17 full iterations are enough
|
||||
|
||||
ldx #$11 ; 2 cycles
|
||||
ldx #$11 // 2 cycles
|
||||
iec_rx_clk_wait1:
|
||||
lda CIA2_PRA ; 4 cycles
|
||||
rol ; 2 cycles, to put CLK in as the last bit
|
||||
bpl iec_rx_not_eoi ; 2 cycles if not jumped
|
||||
dex ; 2 cycles
|
||||
bne iec_rx_clk_wait1 ; 3 cycles if jumped
|
||||
lda CIA2_PRA // 4 cycles
|
||||
rol // 2 cycles, to put CLK in as the last bit
|
||||
bpl iec_rx_not_eoi // 2 cycles if not jumped
|
||||
dex // 2 cycles
|
||||
bne iec_rx_clk_wait1 // 3 cycles if jumped
|
||||
|
||||
;; Timeout - either this is the last byte of stream, or the stream is empty at all.
|
||||
;; Mark end of stream in IOSTATUS
|
||||
jsr kernalstatus_EOI
|
||||
// Timeout - either this is the last byte of stream, or the stream is empty at all.
|
||||
// Mark end of stream in IOSTATUS
|
||||
jsr kernalstatus_EOI
|
||||
|
||||
iec_rx_not_empty:
|
||||
|
||||
;; Pull data for 60 usec to confirm it
|
||||
// Pull data for 60 usec to confirm it
|
||||
jsr iec_release_clk_pull_data
|
||||
jsr iec_wait60us
|
||||
jsr iec_release_clk_data
|
||||
|
||||
iec_rx_not_eoi:
|
||||
|
||||
;; Latch input bits in on rising edge of CLK, eight times for eight bits.
|
||||
// Latch input bits in on rising edge of CLK, eight times for eight bits.
|
||||
ldx #7
|
||||
|
||||
;; Get empty byte to load into.
|
||||
// Get empty byte to load into.
|
||||
lda #$00
|
||||
pha
|
||||
|
||||
iec_rx_bit_loop:
|
||||
|
||||
;; Wait for CLK to release
|
||||
// Wait for CLK to release
|
||||
jsr iec_wait_for_clk_release
|
||||
|
||||
;; (we do this implicitly below, with a tighter routine,
|
||||
;; so that we don't have timing problems, as the requirements
|
||||
;; are quite tight. Basically we need to read the clock and data
|
||||
;; bit from the same byte read.
|
||||
// (we do this implicitly below, with a tighter routine,
|
||||
// so that we don't have timing problems, as the requirements
|
||||
// are quite tight. Basically we need to read the clock and data
|
||||
// bit from the same byte read.
|
||||
|
||||
;; DATA now has the next bit, but inverted (well, except that it turns out not to be).
|
||||
;; DATA is in bit 7, which is a bit annoying.
|
||||
;; But we can clock it out with a ROL instruction
|
||||
;; so that it is in C. We can then ROR it into the
|
||||
;; partial data byte.
|
||||
;; We use ROR so that we shift in from the top, so that
|
||||
;; the first bit we shift in ends up in bit 0 after all
|
||||
;; 8 bits have been read.
|
||||
;; ODD: For some reason we don't need to invert the
|
||||
;; received bits. This is weird, because we invert them
|
||||
;; on the way out, and everything in the protocol seems
|
||||
;; to indicate that we sould do so. But experimentation
|
||||
;; has confirmed the bits don't need inversion on reception.
|
||||
// DATA now has the next bit, but inverted (well, except that it turns out not to be).
|
||||
// DATA is in bit 7, which is a bit annoying.
|
||||
// But we can clock it out with a ROL instruction
|
||||
// so that it is in C. We can then ROR it into the
|
||||
// partial data byte.
|
||||
// We use ROR so that we shift in from the top, so that
|
||||
// the first bit we shift in ends up in bit 0 after all
|
||||
// 8 bits have been read.
|
||||
// ODD: For some reason we don't need to invert the
|
||||
// received bits. This is weird, because we invert them
|
||||
// on the way out, and everything in the protocol seems
|
||||
// to indicate that we sould do so. But experimentation
|
||||
// has confirmed the bits don't need inversion on reception.
|
||||
|
||||
;; Move data bit into C flag, and loop until bit 6 clears
|
||||
;; i.e., the clock has been released.
|
||||
// Move data bit into C flag, and loop until bit 6 clears
|
||||
// i.e., the clock has been released.
|
||||
|
||||
* lda CIA2_PRA
|
||||
!: lda CIA2_PRA
|
||||
rol
|
||||
bpl -
|
||||
bpl !-
|
||||
|
||||
;; Pull it into the data byte
|
||||
// Pull it into the data byte
|
||||
pla
|
||||
ror
|
||||
pha
|
||||
|
||||
;; Wait for CLK to be pulled again, over 300 usec (307 cycles on NTSC)
|
||||
;; consider this a timeout
|
||||
ldy #$19 ; 2 cycles
|
||||
// Wait for CLK to be pulled again, over 300 usec (307 cycles on NTSC)
|
||||
// consider this a timeout
|
||||
ldy #$19 // 2 cycles
|
||||
iec_rx_clk_wait2:
|
||||
lda CIA2_PRA ; 4 cycles
|
||||
rol ; 2 cycles, to put CLK in as the last bit
|
||||
bpl + ; 2 cycles if not jumped
|
||||
dey ; 2 cycles
|
||||
bne iec_rx_clk_wait2 ; 3 cycles if jumped
|
||||
lda CIA2_PRA // 4 cycles
|
||||
rol // 2 cycles, to put CLK in as the last bit
|
||||
bpl !+ // 2 cycles if not jumped
|
||||
dey // 2 cycles
|
||||
bne iec_rx_clk_wait2 // 3 cycles if jumped
|
||||
|
||||
;; Timeout
|
||||
// Timeout
|
||||
jsr kernalstatus_EOI
|
||||
pla
|
||||
plp
|
||||
|
||||
;; Restore registers
|
||||
// Restore registers
|
||||
pla
|
||||
tay
|
||||
pla
|
||||
tax
|
||||
|
||||
sec ; XXX confirm that sec is really a way to report timeout here
|
||||
sec // XXX confirm that sec is really a way to report timeout here
|
||||
rts
|
||||
*
|
||||
;; More bits?
|
||||
!:
|
||||
// More bits?
|
||||
dex
|
||||
bpl iec_rx_bit_loop
|
||||
|
||||
;; Then we must within 1000 usec acknowledge the frame by
|
||||
;; pulling DATA. At this point, CLK is pulled by the
|
||||
;; talker and DATA by us, i.e., we are ready to receive
|
||||
;; the next byte. (p11).
|
||||
// Then we must within 1000 usec acknowledge the frame by
|
||||
// pulling DATA. At this point, CLK is pulled by the
|
||||
// talker and DATA by us, i.e., we are ready to receive
|
||||
// the next byte. (p11).
|
||||
jsr iec_release_clk_pull_data
|
||||
|
||||
;; Retreive the received byte
|
||||
// Retreive the received byte
|
||||
pla
|
||||
|
||||
;; Return no-error
|
||||
// Return no-error
|
||||
plp
|
||||
|
||||
;; Restore registers
|
||||
sta IEC_TMP2 ; $A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html
|
||||
// Restore registers
|
||||
sta IEC_TMP2 // $A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html
|
||||
pla
|
||||
tay
|
||||
pla
|
||||
|
||||
@@ -1,7 +1,7 @@
|
||||
|
||||
iec_set_idle:
|
||||
lda CIA2_PRA
|
||||
ora #BIT_CIA2_PRA_CLK_OUT ; pull
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT - BIT_CIA2_PRA_ATN_OUT ; release
|
||||
ora #BIT_CIA2_PRA_CLK_OUT // pull
|
||||
and #$FF - BIT_CIA2_PRA_DAT_OUT - BIT_CIA2_PRA_ATN_OUT // release
|
||||
sta CIA2_PRA
|
||||
rts
|
||||
@@ -1,37 +1,37 @@
|
||||
;; According to http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
;; pages 7--8.
|
||||
;; See also https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
// According to http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// pages 7--8.
|
||||
// See also https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
|
||||
iec_turnaround_to_listen:
|
||||
|
||||
;; Store .X and .Y on the stack - preserve them
|
||||
// Store .X and .Y on the stack - preserve them
|
||||
txa
|
||||
pha
|
||||
tya
|
||||
pha
|
||||
|
||||
;; Timing is critical here - execute on disabled IRQs
|
||||
// Timing is critical here - execute on disabled IRQs
|
||||
php
|
||||
sei
|
||||
|
||||
;; Pull DATA, release CLK and ATN (we are not sending commands)
|
||||
// Pull DATA, release CLK and ATN (we are not sending commands)
|
||||
jsr iec_pull_data_release_atn_clk
|
||||
|
||||
;; Wait for clock line to be pulled by the drive
|
||||
ldx #$FF ; XXX should we really use that high number?
|
||||
*
|
||||
// Wait for clock line to be pulled by the drive
|
||||
ldx #$FF // XXX should we really use that high number?
|
||||
!:
|
||||
lda CIA2_PRA
|
||||
rol ; to put BIT_CIA2_PRA_CLK_IN as the last (sign) bit
|
||||
bpl +
|
||||
rol // to put BIT_CIA2_PRA_CLK_IN as the last (sign) bit
|
||||
bpl !+
|
||||
dex
|
||||
bne -
|
||||
bne !-
|
||||
|
||||
;; Timeout - XXX what errors do original Kernal report?
|
||||
// Timeout - XXX what errors do original Kernal report?
|
||||
plp
|
||||
jmp iec_return_DEVICE_NOT_FOUND
|
||||
|
||||
;; CLK is pulled by the device, OK
|
||||
*
|
||||
// CLK is pulled by the device, OK
|
||||
!:
|
||||
plp
|
||||
jmp iec_return_success
|
||||
|
||||
|
||||
@@ -1,27 +1,27 @@
|
||||
;; According to http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
;; pages 7--8.
|
||||
;; See also https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
// According to http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// pages 7--8.
|
||||
// See also https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
|
||||
iec_turnaround_to_talk:
|
||||
|
||||
;; Store .X and .Y on the stack - preserve them
|
||||
// Store .X and .Y on the stack - preserve them
|
||||
txa
|
||||
pha
|
||||
tya
|
||||
pha
|
||||
|
||||
;; Timing is critical here - execute on disabled IRQs
|
||||
// Timing is critical here - execute on disabled IRQs
|
||||
php
|
||||
sei
|
||||
|
||||
;; First make sure both CLK, DATA and ATN are released at our side
|
||||
// First make sure both CLK, DATA and ATN are released at our side
|
||||
jsr iec_release_atn
|
||||
jsr iec_release_clk_data
|
||||
|
||||
;; Wait till device releases CLK line
|
||||
// Wait till device releases CLK line
|
||||
jsr iec_wait_for_clk_release
|
||||
|
||||
;; Pull CLK line, it should be held by talker
|
||||
// Pull CLK line, it should be held by talker
|
||||
jsr iec_pull_clk_release_data
|
||||
|
||||
plp
|
||||
|
||||
@@ -1,96 +1,96 @@
|
||||
|
||||
;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
// Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
|
||||
;; Expects byte to send in IEC_TMP2 ($A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html)
|
||||
;; Carry flag set = signal EOI
|
||||
;;
|
||||
;; Preserves .X and .Y registers
|
||||
// Expects byte to send in IEC_TMP2 ($A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html)
|
||||
// Carry flag set = signal EOI
|
||||
//
|
||||
// Preserves .X and .Y registers
|
||||
|
||||
|
||||
iec_tx_byte:
|
||||
|
||||
;; Store .X and .Y on the stack - preserve them
|
||||
// Store .X and .Y on the stack - preserve them
|
||||
txa
|
||||
pha
|
||||
tya
|
||||
pha
|
||||
|
||||
;; Notify all devices that we are going to send a byte
|
||||
;; and it is going to be a data byte (released ATN)
|
||||
// Notify all devices that we are going to send a byte
|
||||
// and it is going to be a data byte (released ATN)
|
||||
jsr iec_release_atn_clk_data
|
||||
|
||||
;; Common part of iec_tx_byte and iec_tx_command
|
||||
;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
;; and http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
// Common part of iec_tx_byte and iec_tx_command
|
||||
// Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
// and http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
|
||||
|
||||
iec_tx_common:
|
||||
|
||||
;; Timing is critical here - execute on disabled IRQs
|
||||
// Timing is critical here - execute on disabled IRQs
|
||||
php
|
||||
sei
|
||||
|
||||
;; Wait till all receivers are ready, they should all release DATA
|
||||
// Wait till all receivers are ready, they should all release DATA
|
||||
jsr iec_wait_for_data_release
|
||||
|
||||
bcc +
|
||||
bcc !+
|
||||
|
||||
;; At this point a delay 256 usec or more is considered EOI,
|
||||
;; receiver should now acknowledge it by pulling data for at least 60 usec
|
||||
;; Keep the implementation as simple as possible: data should be released now
|
||||
;; so wait until it's pushed and released again
|
||||
// At this point a delay 256 usec or more is considered EOI,
|
||||
// receiver should now acknowledge it by pulling data for at least 60 usec
|
||||
// Keep the implementation as simple as possible: data should be released now
|
||||
// so wait until it's pushed and released again
|
||||
|
||||
jsr iec_wait_for_data_pull
|
||||
jsr iec_wait_for_data_release
|
||||
*
|
||||
;; Pull CLK back to indicate that DATA is not valid, keep it for 60us
|
||||
;; We can use this routine as we don't hold DATA anyway (and its state doesn't even matter)
|
||||
!:
|
||||
// Pull CLK back to indicate that DATA is not valid, keep it for 60us
|
||||
// We can use this routine as we don't hold DATA anyway (and its state doesn't even matter)
|
||||
|
||||
jsr iec_pull_clk_release_data_oneshot
|
||||
jsr iec_wait60us
|
||||
|
||||
;; Now, we can start transmission of 8 bits of data
|
||||
// Now, we can start transmission of 8 bits of data
|
||||
ldx #7
|
||||
|
||||
iec_tx_common_sendbit:
|
||||
;; Is next bit 0 or 1?
|
||||
// Is next bit 0 or 1?
|
||||
lda IEC_TMP2
|
||||
lsr
|
||||
sta IEC_TMP2
|
||||
bcs +
|
||||
bcs !+
|
||||
|
||||
;; Bit is 0
|
||||
// Bit is 0
|
||||
jsr iec_release_clk_pull_data
|
||||
jmp iec_tx_common_bit_is_sent
|
||||
*
|
||||
;; Bit is 1
|
||||
!:
|
||||
// Bit is 1
|
||||
jsr iec_release_clk_data
|
||||
|
||||
iec_tx_common_bit_is_sent:
|
||||
|
||||
;; Wait 20us, so that device(s) can pick DATA
|
||||
// Wait 20us, so that device(s) can pick DATA
|
||||
jsr iec_wait20us
|
||||
|
||||
;; Pull CLK for 20us again, before sending the next bit
|
||||
;; or performing any other action
|
||||
// Pull CLK for 20us again, before sending the next bit
|
||||
// or performing any other action
|
||||
jsr iec_pull_clk_release_data_oneshot
|
||||
jsr iec_wait20us
|
||||
|
||||
;; More bits to send?
|
||||
// More bits to send?
|
||||
dex
|
||||
bpl iec_tx_common_sendbit
|
||||
|
||||
plp
|
||||
|
||||
;; Give device time to tell if they are busy by pulling DATA
|
||||
;; They should do it within 1ms
|
||||
// Give device time to tell if they are busy by pulling DATA
|
||||
// They should do it within 1ms
|
||||
ldx #$FF
|
||||
* lda CIA2_PRA
|
||||
;; BPL here is checking that bit 7 clears,
|
||||
;; i.e, that the DATA line is pulled by drive
|
||||
bpl +
|
||||
!: lda CIA2_PRA
|
||||
// BPL here is checking that bit 7 clears,
|
||||
// i.e, that the DATA line is pulled by drive
|
||||
bpl !+
|
||||
dex
|
||||
bne -
|
||||
bmi +
|
||||
bne !-
|
||||
bmi !+
|
||||
jmp iec_return_DEVICE_NOT_FOUND
|
||||
*
|
||||
!:
|
||||
jmp iec_return_success
|
||||
@@ -1,40 +1,40 @@
|
||||
|
||||
;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
// Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
|
||||
;; Expects byte to send in IEC_TMP2 ($A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html)
|
||||
;; Carry flag set = signal EOI
|
||||
;;
|
||||
;; Preserves .X and .Y registers
|
||||
// Expects byte to send in IEC_TMP2 ($A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html)
|
||||
// Carry flag set = signal EOI
|
||||
//
|
||||
// Preserves .X and .Y registers
|
||||
|
||||
|
||||
iec_tx_command:
|
||||
|
||||
;; Store .X and .Y on the stack - preserve them
|
||||
// Store .X and .Y on the stack - preserve them
|
||||
txa
|
||||
pha
|
||||
tya
|
||||
pha
|
||||
|
||||
;; Notify all devices that we are going to send a byte
|
||||
;; and it is going to be a command (pulled ATN)
|
||||
// Notify all devices that we are going to send a byte
|
||||
// and it is going to be a command (pulled ATN)
|
||||
jsr iec_pull_atn_clk_release_data
|
||||
|
||||
;; Give devices time to respond (response is mandatory!) by pulling DATA
|
||||
// Give devices time to respond (response is mandatory!) by pulling DATA
|
||||
jsr iec_wait1ms
|
||||
lda CIA2_PRA ; pulled DATA = highest bit 0 = 'plus'
|
||||
bpl +
|
||||
lda CIA2_PRA // pulled DATA = highest bit 0 = 'plus'
|
||||
bpl !+
|
||||
jmp iec_return_DEVICE_NOT_FOUND
|
||||
*
|
||||
;; At least one device responded, but they are still allowed to stall
|
||||
;; (can be busy processing something), we have to wait till they are all
|
||||
;; ready (or bored with DOS attack...)
|
||||
;; Release back CLK, keep DATA released - to ask devices for status.
|
||||
!:
|
||||
// At least one device responded, but they are still allowed to stall
|
||||
// (can be busy processing something), we have to wait till they are all
|
||||
// ready (or bored with DOS attack...)
|
||||
// Release back CLK, keep DATA released - to ask devices for status.
|
||||
|
||||
jsr iec_release_clk_data
|
||||
|
||||
;; Common part of iec_txbyte and iec_tx_common - waits for devices
|
||||
;; and transmits a byte
|
||||
// Common part of iec_txbyte and iec_tx_common - waits for devices
|
||||
// and transmits a byte
|
||||
|
||||
clc ; Carry flag set is used for EOI mark
|
||||
clc // Carry flag set is used for EOI mark
|
||||
jmp iec_tx_common
|
||||
|
||||
@@ -1,18 +1,18 @@
|
||||
|
||||
;; Routine to finalize some IEC commands - which do not end in turnaround and are not followed by others
|
||||
;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
// Routine to finalize some IEC commands - which do not end in turnaround and are not followed by others
|
||||
// Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
|
||||
|
||||
|
||||
iec_tx_command_finalize:
|
||||
|
||||
;; Store .X and .Y on the stack - preserve them
|
||||
// Store .X and .Y on the stack - preserve them
|
||||
txa
|
||||
pha
|
||||
tya
|
||||
pha
|
||||
|
||||
;; Give device some time to complete command reception, release ATN,
|
||||
;; give it some time again before (possible) next command
|
||||
// Give device some time to complete command reception, release ATN,
|
||||
// give it some time again before (possible) next command
|
||||
jsr iec_wait20us
|
||||
jsr iec_set_idle
|
||||
jsr iec_wait20us
|
||||
|
||||
@@ -1,15 +1,15 @@
|
||||
|
||||
;; Flush the IEC output buffer (if not empty) - send byte with EOI
|
||||
;;
|
||||
;; Preserves .X, .Y and .A registers
|
||||
// Flush the IEC output buffer (if not empty) - send byte with EOI
|
||||
//
|
||||
// Preserves .X, .Y and .A registers
|
||||
|
||||
iec_tx_flush:
|
||||
|
||||
pha
|
||||
lda C3PO
|
||||
beq +
|
||||
sec ; send it with EOI
|
||||
jsr iec_tx_byte ; send the command regardless of the status
|
||||
*
|
||||
beq !+
|
||||
sec // send it with EOI
|
||||
jsr iec_tx_byte // send the command regardless of the status
|
||||
!:
|
||||
pla
|
||||
rts
|
||||
@@ -1,21 +1,21 @@
|
||||
|
||||
;;
|
||||
;; Wait 1 ms (1000 usec)
|
||||
;;
|
||||
;; On NTSC this means 1023 cycles (slightly less on PAL, but we have to be sure).
|
||||
;; We can't count on badlines, as the screen might be disabled.
|
||||
;; Delay here is implemeented using VIC-II raster register. Since one raster is
|
||||
;; 63 cycles, we need at least 17 full rasters to be 100% sure we wait enough
|
||||
//
|
||||
// Wait 1 ms (1000 usec)
|
||||
//
|
||||
// On NTSC this means 1023 cycles (slightly less on PAL, but we have to be sure).
|
||||
// We can't count on badlines, as the screen might be disabled.
|
||||
// Delay here is implemeented using VIC-II raster register. Since one raster is
|
||||
// 63 cycles, we need at least 17 full rasters to be 100% sure we wait enough
|
||||
|
||||
|
||||
iec_wait1ms:
|
||||
ldx #18 ; we probably won't start with the beginning of raster
|
||||
ldx #18 // we probably won't start with the beginning of raster
|
||||
lda VIC_RASTER
|
||||
*
|
||||
!:
|
||||
cmp VIC_RASTER
|
||||
beq -
|
||||
beq !-
|
||||
lda VIC_RASTER
|
||||
dex
|
||||
bne -
|
||||
bne !-
|
||||
|
||||
rts
|
||||
@@ -1,22 +1,22 @@
|
||||
|
||||
iec_wait20us:
|
||||
|
||||
;; Wait 20usec
|
||||
// Wait 20usec
|
||||
|
||||
;; PAL:
|
||||
;; - CPU frequency 0.985248 MHz, we need to waste at least 20 cycles
|
||||
;; NTSC:
|
||||
;; - CPU frequency 1.022727 MHz, we need to waste at least 21 cycles
|
||||
// PAL:
|
||||
// - CPU frequency 0.985248 MHz, we need to waste at least 20 cycles
|
||||
// NTSC:
|
||||
// - CPU frequency 1.022727 MHz, we need to waste at least 21 cycles
|
||||
|
||||
;; Waste cycles by reading some unimportant memory location
|
||||
;; in order not to clutter VICE debug logs
|
||||
// Waste cycles by reading some unimportant memory location
|
||||
// in order not to clutter VICE debug logs
|
||||
|
||||
ora $03FF ; 4 cycles
|
||||
ora $03FF ; 4 cycles
|
||||
rts ; 6 cycles
|
||||
ora $03FF // 4 cycles
|
||||
ora $03FF // 4 cycles
|
||||
rts // 6 cycles
|
||||
|
||||
;; 6 cycles JSR to routine,
|
||||
;; 14 cycles routine with RTS
|
||||
;; 1 cycle to fetch next instruction
|
||||
;; ---
|
||||
;; 21 cycles
|
||||
// 6 cycles JSR to routine,
|
||||
// 14 cycles routine with RTS
|
||||
// 1 cycle to fetch next instruction
|
||||
// ---
|
||||
// 21 cycles
|
||||
@@ -1,23 +1,23 @@
|
||||
|
||||
iec_wait60us:
|
||||
|
||||
;; Wait 60usec
|
||||
// Wait 60usec
|
||||
|
||||
;; PAL:
|
||||
;; - CPU frequency 0.985248 MHz, we need to waste at least 60 cycles
|
||||
;; NTSC:
|
||||
;; - CPU frequency 1.022727 MHz, we need to waste at least 62 cycles
|
||||
// PAL:
|
||||
// - CPU frequency 0.985248 MHz, we need to waste at least 60 cycles
|
||||
// NTSC:
|
||||
// - CPU frequency 1.022727 MHz, we need to waste at least 62 cycles
|
||||
|
||||
;; Waste cycles in a loop
|
||||
// Waste cycles in a loop
|
||||
|
||||
ldy #$0A ; 2 cycles
|
||||
* dey ; 2 cycles * 10
|
||||
bpl - ; 3 cycles * 9 + 2 cycles
|
||||
rts ; 6 cycles
|
||||
ldy #$0A // 2 cycles
|
||||
!: dey // 2 cycles * 10
|
||||
bpl !- // 3 cycles * 9 + 2 cycles
|
||||
rts // 6 cycles
|
||||
|
||||
;; 6 cycles JSR to routine,
|
||||
;; 57 cycles routine with RTS
|
||||
;; 1 cycle to fetch next instruction
|
||||
;; ---
|
||||
;; 64 cycles
|
||||
// 6 cycles JSR to routine,
|
||||
// 57 cycles routine with RTS
|
||||
// 1 cycle to fetch next instruction
|
||||
// ---
|
||||
// 64 cycles
|
||||
|
||||
@@ -2,7 +2,7 @@
|
||||
iec_wait_for_data_pull:
|
||||
|
||||
lda CIA2_PRA
|
||||
;; Check the highest bit, which is DATA IN,
|
||||
;; (highest bit set = negative value)
|
||||
// Check the highest bit, which is DATA IN,
|
||||
// (highest bit set = negative value)
|
||||
bmi iec_wait_for_data_pull
|
||||
rts
|
||||
@@ -2,7 +2,7 @@
|
||||
iec_wait_for_data_release:
|
||||
|
||||
lda CIA2_PRA
|
||||
;; Check the highest bit, which is DATA IN,
|
||||
;; (highest bit set = negative value)
|
||||
// Check the highest bit, which is DATA IN,
|
||||
// (highest bit set = negative value)
|
||||
bpl iec_wait_for_data_release
|
||||
rts
|
||||
Reference in new issue
Block a user