;NB65 API example in DASM format (http://www.atari2600.org/DASM/)
processor 6502
include "../inc/nb65_constants.i"
;useful macros
mac ldax
lda [{1}]
ldx [{1}]+1
endm
mac ldaxi
lda #<[{1}]
ldx #>[{1}]
endm
mac stax
sta [{1}]
stx [{1}]+1
endm
mac cout
lda [{1}]
jsr print_a
endm
mac print_cr
cout #13
jsr print_a
endm
mac nb65call
ldy [{1}]
jsr NB65_DISPATCH_VECTOR
endm
mac print
ldaxi [{1}]
ldy #NB65_PRINT_ASCIIZ
jsr NB65_DISPATCH_VECTOR
endm
;some routines & zero page variables
print_a equ $ffd2
temp_ptr equ $FB ; scratch space in page zero
;start of code
;NO BASIC stub! needs to be direct booted via TFTP
org $1000
ldaxi #NB65_CART_SIGNATURE ;where signature should be in cartridge (if cart is banked in)
jsr look_for_signature
bcc found_nb65_signature
ldaxi #NB65_RAM_STUB_SIGNATURE ;where signature should be in a RAM stub
jsr look_for_signature
bcs nb65_signature_not_found
jsr NB65_RAM_STUB_ACTIVATE ;we need to turn on NB65 cartridge
jmp found_nb65_signature
nb65_signature_not_found
ldaxi #nb65_api_not_found_message
jsr print_ax
rts
found_nb65_signature
lda NB65_API_VERSION
cmp #02
bpl .version_ok
print incorrect_version
jmp reset_after_keypress
.version_ok
print #initializing
nb65call #NB65_INITIALIZE
bcc .init_ok
print_cr
print #failed
print_cr
jsr print_errorcode
jmp reset_after_keypress
.init_ok
;if we got here, we have found the NB65 API and initialised the IP stack
;print out the current configuration
nb65call #NB65_PRINT_IP_CONFIG
listen_on_port_80
ldaxi #scratch_buffer
stax tcp_buffer_ptr
print #waiting
ldaxi #80 ;port number
stax nb65_param_buffer+NB65_TCP_PORT
stx nb65_param_buffer+NB65_TCP_REMOTE_IP
stx nb65_param_buffer+NB65_TCP_REMOTE_IP+1
stx nb65_param_buffer+NB65_TCP_REMOTE_IP+2
stx nb65_param_buffer+NB65_TCP_REMOTE_IP+3
ldaxi #http_callback
stax nb65_param_buffer+NB65_TCP_CALLBACK
ldaxi #nb65_param_buffer
nb65call #NB65_TCP_CONNECT ;wait for inbound connect
bcc .connected_ok
print #error_while_waiting
jsr print_errorcode
jmp reset_after_keypress
.connected_ok
print #ok
lda #0
sta connection_closed
sta found_eol
.main_polling_loop
jsr NB65_PERIODIC_PROCESSING_VECTOR
lda found_eol
beq .no_eol_yet
nb65call #NB65_PRINT_HEX
lda #"!"
jsr print_a
ldaxi #html_length
stax nb65_param_buffer+NB65_TCP_PAYLOAD_LENGTH
ldaxi #html
stax nb65_param_buffer+NB65_TCP_PAYLOAD_POINTER
ldaxi #nb65_param_buffer
nb65call #NB65_SEND_TCP_PACKET
nb65call #NB65_TCP_CLOSE_CONNECTION
jmp listen_on_port_80
.no_eol_yet
lda connection_closed
beq .main_polling_loop
jmp listen_on_port_80
;look for NB65 signature at location pointed at by AX
look_for_signature subroutine
stax temp_ptr
ldy #3
.check_one_byte
lda (temp_ptr),y
cmp nb65_signature,y
bne .bad_match
dey
bpl .check_one_byte
clc
rts
.bad_match
sec
rts
print_ax subroutine
stax temp_ptr
ldy #0
.next_char
lda (temp_ptr),y
beq .done
jsr print_a
iny
jmp .next_char
.done
rts
get_key
jsr $ffe4
cmp #0
beq get_key
rts
reset_after_keypress
print #press_a_key_to_continue
jsr get_key
jmp $fce2 ;do a cold start
print_errorcode
print #error_code
nb65call #NB65_GET_LAST_ERROR
nb65call #NB65_PRINT_HEX
print_cr
rts
;http callback - will be executed whenever data arrives on the TCP connection
http_callback
ldaxi #nb65_param_buffer
nb65call #NB65_GET_INPUT_PACKET_INFO
lda nb65_param_buffer+NB65_PAYLOAD_LENGTH+1
cmp #$ff
bne .not_eof
lda #1
sta connection_closed
rts
.not_eof
lda #"*"
jsr print_a
ldax nb65_param_buffer+NB65_PAYLOAD_POINTER
stax tcp_inbound_data_ptr
ldax nb65_param_buffer+NB65_PAYLOAD_LENGTH
stax tcp_inbound_data_length
;copy this chunk to our input buffer
ldax tcp_buffer_ptr
stax nb65_param_buffer+NB65_BLOCK_DEST
ldax tcp_inbound_data_ptr
stax nb65_param_buffer+NB65_BLOCK_SRC
ldax tcp_inbound_data_length
stax nb65_param_buffer+NB65_BLOCK_SIZE
ldaxi #nb65_param_buffer
nb65call #NB65_BLOCK_COPY
;increment the pointer into the input buffer
clc
lda tcp_buffer_ptr
adc tcp_inbound_data_length
sta tcp_buffer_ptr
sta temp_ptr
lda tcp_buffer_ptr+1
adc tcp_inbound_data_length+1
sta tcp_buffer_ptr+1
sta temp_ptr
;put a null byte at the end (assumes we have set temp_ptr already)
lda #0
tay
sta (temp_ptr),y
;look for EOL ($0D) in input
sta found_eol
ldaxi #scratch_buffer
stax get_next_byte+1
.look_for_eol
jsr get_next_byte
cmp #$0a
bne .found_eol
cmp #$0d
bne .not_eol
.found_eol
inc found_eol
rts
.not_eol
cmp #0
bne .look_for_eol
rts
;constants
nb65_api_not_found_message dc.b "ERROR - NB65 API NOT FOUND.",13,0
incorrect_version dc.b "ERROR - NB65 API MUST BE AT LEAST VERSION 2.",13,0
nb65_signature dc.b $4E,$42,$36,$35 ; "NB65" - API signature
initializing dc.b "INITIALIZING ",13,0
error_code dc.b "ERROR CODE: $",0
error_while_waiting dc.b "ERROR WHILE "
waiting dc.b "WAITING FOR CLIENT CONNECTION",13,0
press_a_key_to_continue dc.b "PRESS ANY KEY TO CONTINUE",0
mode dc.b " MODE",13,0
disconnected dc.b 13,"CONNECTION CLOSED",13,0
failed dc.b "FAILED ", 0
ok dc.b "OK ", 0
transmission_error dc.b "ERROR WHILE SENDING ",0
html dc.b "c64 test page