emailler/client/examples/dumb_telnet.asm

208 lines
4.2 KiB
NASM

;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
;prompt for a hostname, then resolve to an IP address
.get_hostname
print #remote_host
nb65call #NB65_INPUT_HOSTNAME
bcc .host_entered
;if no host entered, then bail.
jmp reset_after_keypress
.host_entered
stax nb65_param_buffer
print_cr
print #resolving
ldax nb65_param_buffer
nb65call #NB65_PRINT_ASCIIZ
print_cr
ldaxi #nb65_param_buffer
nb65call #NB65_DNS_RESOLVE
bcc .resolved_ok
print #failed
print_cr
jsr print_errorcode
jmp .get_hostname
.resolved_ok
.get_port
print #remote_port
nb65call #NB65_INPUT_PORT_NUMBER
bcc .port_entered
;if no port entered, then assume port 23
ldaxi #23
.port_entered
stax nb65_param_buffer+NB65_TCP_PORT
ldaxi #tcp_callback
stax nb65_param_buffer+NB65_TCP_CALLBACK
print #connecting
ldaxi #nb65_param_buffer
nb65call #NB65_TCP_CONNECT
bcc .connect_ok
print_cr
print #failed
jsr print_errorcode
jmp .get_hostname
.connect_ok
print #ok
.loop_forever
jsr NB65_PERIODIC_PROCESSING_VECTOR
jmp .loop_forever
;tcp callback - will be executed whenever data arrives on the TCP connection
tcp_callback
.byte $92
rts
;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
;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
resolving dc.b "RESOLVING ",0
connecting dc.b "CONNECTING ",0
remote_host dc.b "REMOTE HOST - BLANK TO QUIT",13,": ",0
remote_port dc.b "REMOTE PORT - BLANK FOR TELNET DEFAULT",13,": ",0
press_a_key_to_continue dc.b "PRESS A KEY TO CONTINUE",13,0
failed dc.b "FAILED ", 0
ok dc.b "OK ", 0
;variables
nb65_param_buffer DS.B $20