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06204-assemblable.asm
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06204-assemblable.asm
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ORG 0x0000
RST_0:
NOP ;reset vector
DI ;turn off interrupts
LXI SP,var_FFD0 ;preparing the stack
JMP sub_main
;**************************************************************************************************
ORG 0x0008
RST_1:
NOP
JMP RST_7
JMP RST_7
NOP
;**************************************************************************************************
ORG 0x0010
RST_2:
NOP
JMP RST_7
JMP RST_7
NOP
;**************************************************************************************************
ORG 0x0018
RST_3:
LXI H,0x8000
SHLD error_counter_FF12 ;store HL into ram
RET
NOP
;**************************************************************************************************
ORG 0x0020
RST_4: ;observed to be the keyboard input handler
PUSH PSW
PUSH B
PUSH D
PUSH H
JMP keyboard_handler
NOP
;**************************************************************************************************
ORG 0x0028
RST_5:
PUSH PSW ;11
PUSH B ;11
PUSH D ;11
PUSH H ;11
JMP int_5_handler ; 10 i think this is the comms input interrupt
NOP
;**************************************************************************************************
ORG 0x0030
RST_6:
PUSH PSW
IN 0x78 ;read interface card status
PUSH PSW
JMP label_05C4
NOP
;**************************************************************************************************
ORG 0x0038
RST_7: ;warmboot
DI ;disable interrupts
LXI SP,var_FFD0 ;load stack pointer
JMP RST_0 ;hard reboot
NOP
;**************************************************************************************************
ORG 0x0040
sub_main:
MVI A,0x06 ;reset status_d7 if restat_state_machin and reset UF8
OUT 0x78 ;write status to interface card
LXI H,var_F000 ;set hl to the first ram address
MVI B,0x00 ;init zero into b
init_mem_loop:
MOV M,B
INX H
MOV A,H
ORA A
JNZ init_mem_loop ;has the address counter rolled over at the top of mem?
;init ram variables
LXI H,var_FF14
SHLD var_FF04 ;init variable var_f
SHLD var_FF0C
LXI H,var_F020
SHLD char_buff_ptr
LXI H,0x0642
SHLD var_FF0A ;FF0A=06 FF0B=42
LXI H,var_FFD0 ; i assume this is an addr, (it is!)
SHLD var_FFFA
SHLD var_FFF8
IN 0x78 ;read interface card status
ANI 0x20 ; is the byte in the buffer for me? (interface card status_d5)
JNZ label_007A
MVI A,0x01
STA var_FF03
label_007A:
MVI A,0x10 ;send 0x10 then 0x7f
OUT 0x60 ;write to interface card register low ;send a \n
XRA A ;
OUT 0x60 ;write to interface card register low ;send a \x7f command (redraw?)
IN 0x40
RAL ;test port40 for a bit
JNC label_0089 ;
MVI B,0x7F ;yes, B_reg = 0x7f, else B_reg = 0x00 for the mask seems to check if the display
;should be cleared or not
label_0089:
CALL mask_display ;A_reg = mask_display(B_reg)
OUT 0x40
MVI A,0x02 ;whats this about?
OUT 0x50
IN 0x50 ;read keyboard
idle_loop: ; this was observed to be the idle loop
LXI H,0x0028 ; init HL
IN 0x40
CMA
ANI 0x01
STA var_FF02
RAR
JNC label_00A6 ; test port 0x40 bit to determine if HL chould be different
LXI H,0x0050 ;change HL
label_00A6:
SHLD var_FFFC
EI ;enable interrupts
LHLD var_FFFA ;load HL from ram
MOV A,M
ORA A
CNZ sub_041A
LDA var_FF09
RAR
JNC label_00CA
LDA printer_not_ready_flag_FF0E
RAR
JC label_00CA
IN 0x70 ;check printer status bits ;
ANI 0x10 ; test port 0x70 bit 0x10
CNZ terminal_cmd_handler_024D ; bit is set
CZ terminal_emu_handler_00E1 ;if not set
label_00CA:
IN 0x48 ;check keyboard status bits
ANI 0x40 ;test if the keyboard latch is set
CNZ RST_4
LDA var_FF03
RAR
JC idle_loop
MVI A,0x40 ;
OUT 0x78 ;write status to interface card
IN 0x68 ;read interface card buffer ;
JMP idle_loop
;**************************************************************************************************
terminal_emu_handler_00E1: terminal_emu_handler_00E1(char_buff_ptr)
PUSH PSW
PUSH B
PUSH D
PUSH H
LHLD char_buff_ptr ;load HL from ram
MOV A,M ;switch(A_reg)
CPI 0x0D
JZ handle_CR_0145 ;case 0x0d: handle_CR_0145()
CPI 0x0A
JZ handle_LF_0172 ;case 0x0a: handle_LF_0172()
CPI 0x0B
JZ handle_VT_01A5 ;case 0x0b: handle_VT_01A5()
CPI 0x20
JZ handle_SP_01DD ;case 0x20: handle_SP_01DD()
CALL test_printer_ready_021E ;default
IN 0x70 ;check printer status bits
ANI 0x08
JZ return_from_int_subroutine ;return
MOV A,M
CPI 0xB8
CZ return_A_0x20
CPI 0xB6
JZ label_022E
label_0112: ;label_0112(A_reg, HL_reg)
OUT 0x58 ;write to interface card register high
MVI A,0x80
OUT 0x60 ;write to interface card register low
XRA A
OUT 0x60 ;write to interface card register low
INX H
SHLD char_buff_ptr
label_011F:
CALL test_printer_ready_021E
IN 0x48 ;check keyboard status bits
IN 0x70 ;check printer status bits
ANI 0x04
JZ label_011F
LDA var_FF0B
MOV E,A
MVI D,0x00
LHLD var_cursor_col_FF0F ;load HL from ram
DAD D
SHLD var_cursor_col_FF0F ; var_cursor_col_FF0F = var_cursor_col_FF0F + var_FF0B;
MOV A,E
OUT 0x58 ;write to interface card register high
MVI A,0x40
OUT 0x60 ;write to interface card register low
XRA A
OUT 0x60 ;write to interface card register low
JMP return_from_int_subroutine ;return
;**************************************************************************************************
handle_CR_0145:
CALL test_printer_ready_021E
IN 0x70 ;check printer status bits
ANI 0x04
JZ return_from_int_subroutine ;return
LHLD char_buff_ptr ;
INX H ;
SHLD char_buff_ptr ; increment char_buff_ptr
LHLD var_cursor_col_FF0F ;load HL from ram
MOV A,L
OUT 0x58 ;write to interface card register high
MOV A,H
ORI 0x04
OUT 0x60 ;write to interface card register low
ORI 0x40
OUT 0x60 ;write to interface card register low
ANI 0xBF
OUT 0x60 ;write to interface card register low
carriage_return_cursor:
LXI H,0x0000
SHLD var_cursor_col_FF0F
JMP return_from_int_subroutine ;return
;**************************************************************************************************
handle_LF_0172:
CALL test_printer_ready_021E
IN 0x70 ;check printer status bits
ANI 0x02
IN 0x48 ;check keyboard status bits
JZ handle_LF_0172
LDA var_FF0A ;
MOV D,A ;
LDA var_cursor_line_FF11 ;
INR A ;
CMP D ;
JNZ label_018B ;var_cursor_line_FF11 != (var_FF0A)
XRA A
label_018B:
STA var_cursor_line_FF11
MVI A,0x08
OUT 0x58 ;write to interface card register high
MVI A,0x20
OUT 0x60 ;write to interface card register low
XRA A
OUT 0x60 ;write to interface card register low
label_0199:
LXI H,var_F020
SHLD char_buff_ptr
STA var_FF09
JMP label_0500
;**************************************************************************************************
handle_VT_01A5:
CALL test_printer_ready_021E
IN 0x70 ;check printer status bits
ANI 0x02
IN 0x48 ;check keyboard status bits
JZ handle_VT_01A5 ;sure looks like an infinite loop if the modifier key is not pressed
LDA var_cursor_line_FF11
MOV D,A
LDA var_FF0A
SUB D
MOV L,A
MVI H,0x00
DAD H
DAD H
DAD H
MOV A,L
OUT 0x58 ;write to interface card register high
MOV A,H
ANI 0x03
OUT 0x60 ;write to interface card register low
ORI 0x20
OUT 0x60 ;write to interface card register low
ANI 0xDF
OUT 0x60 ;write to interface card register low
LHLD char_buff_ptr ;load HL from ram
INX H
SHLD char_buff_ptr ;store incremented var
XRA A
STA var_cursor_line_FF11 ;zero the cursor position
JMP return_from_int_subroutine ;return
;**************************************************************************************************
handle_SP_01DD:
CALL test_printer_ready_021E
IN 0x48 ;check keyboard status bits
IN 0x70 ;check printer status bits
ANI 0x04
JZ handle_SP_01DD
LDA var_FF0B
MOV C,A
MVI B,0x00
XCHG
LXI H,0x0000
label_01F3:
DAD B
INX D
LDAX D
CPI 0x20
JZ label_01F3
XCHG ;HL<=>DE
SHLD char_buff_ptr
CPI 0x0D
JZ return_from_int_subroutine ;return
IN 0x48 ;check keyboard status bits
MOV A,E
OUT 0x58 ;write to interface card register high
MOV A,D
OUT 0x60 ;write to interface card register low
ORI 0x40
OUT 0x60 ;write to interface card register low
ANI 0xBF
OUT 0x60 ;write to interface card register low
LHLD var_cursor_col_FF0F ;load HL from ram
DAD D
SHLD var_cursor_col_FF0F
JMP return_from_int_subroutine ;return
;**************************************************************************************************
test_printer_ready_021E:
IN 0x70 ;check printer status bits
RAR
JC pop_f_err_printer_not_ready
ANI 0x10
JZ pop_f_err_printer_not_ready
RET
;**************************************************************************************************
pop_f_err_printer_not_ready:
POP PSW
JMP err_printer_not_ready ;does not return from this call
label_022E:
MVI A,0x3D
OUT 0x58 ;write to interface card register high
MVI A,0x80
OUT 0x60 ;write to interface card register low
XRA A
OUT 0x60 ;write to interface card register low
label_0239:
CALL test_printer_ready_021E
IN 0x48 ;check keyboard status bits
IN 0x70 ;check printer status bits
ANI 0x08
JZ label_0239
MVI A,0x2F
JMP label_0112
;**************************************************************************************************
return_A_0x20:
MVI A,0x20
RET
;**************************************************************************************************
terminal_cmd_handler_024D:
PUSH PSW
PUSH B
PUSH D
PUSH H
MVI A,0x00
OUT 0x60 ;write to interface card register low
CALL is_printer_ready
ANI 0x08
JZ return_from_int_subroutine ;return
LHLD char_buff_ptr ;switch(char_buff_ptr)P{
MOV A,M
CPI 0x0A
JZ label_02A0 ;case 0x0a: label_02A0()
CPI 0xB8
CZ return_A_0x20 ;case 0xb8: return_A_0x20()
CPI 0xB6
CZ return_A_0x20 ;case 0xB6: return_A_0x20
CPI 0x0B
JNZ label_027D ;case 0x0b: label_027D
JMP label_027B ;default: label_027B
;**************************************************************************************************
is_printer_ready_from_subroutine:
CALL is_printer_ready
label_027B:
MVI A,0x0C
label_027D:
CMA
OUT 0x58 ;write to interface card register high
MVI A,0x80
OUT 0x60 ;write to interface card register low
XRA A
OUT 0x60 ;write to interface card register low
INX H
SHLD char_buff_ptr
JMP return_from_int_subroutine ;return
;**************************************************************************************************
is_printer_ready:
IN 0x70 ;check printer status bits ;printer
RAR
JC pop_b_and_jmp_err_printer_not_ready ;does not return from this call
RAR
JNC pop_b_and_jmp_err_printer_not_ready ;does not return from this call
RET
;**************************************************************************************************
pop_b_and_jmp_err_printer_not_ready:
POP B
JMP err_printer_not_ready ;does not return from this call
call_is_printer_ready: ;A_reg - call_is_printer_ready()
CALL is_printer_ready
label_02A0:
MVI A,0xF5
OUT 0x58 ;write to interface card register high
MVI A,0x80
OUT 0x60 ;write to interface card register low
XRA A
OUT 0x60 ;write to interface card register low
XRA A
JMP label_0199
;**************************************************************************************************
label_02AF:
MVI A,0x05 ;reset UF8 and UC7B and latch
OUT 0x78 ;write status to interface card
MVI B,0x28
MVI C,0x0C
LDA var_FF02
RAR
JNC label_02C2
MVI B,0x50
MVI C,0x18
label_02C2:
MOV A,B
STA var_FF22
LXI H,var_F020
LXI D,var_C000_display_buff
label_02CC:
IN 0x48 ;check keyboard status bits
LDAX D
ANI 0x7F
CPI 0x00
JNZ label_02DB
MVI A,0x20
JMP label_0300
label_02DB:
CPI 0x1D
JNZ label_02E5
MVI A,0x5F
JMP label_0300
label_02E5:
CPI 0x1E
JNZ label_02EF
MVI A,0xB8
JMP label_0300
label_02EF:
CPI 0x1C
JNZ label_02F9
MVI A,0xB6
JMP label_0300
label_02F9:
CPI 0x1F
JNZ label_0300
MVI A,0x5E
label_0300:
MOV M,A
INX H
INX D
DCR B
JNZ label_02CC
MVI M,0x0D
INX H
MVI M,0x0A
LXI H,var_F020
SHLD char_buff_ptr
MVI A,0x01
STA var_FF09
label_0317:
LDA printer_not_ready_flag_FF0E
RAR
JC label_0332
LDA var_FF09
RAR
JNC label_0345
IN 0x70 ;check printer status bits
ANI 0x10
CNZ terminal_cmd_handler_024D
CZ terminal_emu_handler_00E1
JMP label_0317
label_0332:
MVI A,0x10
OUT 0x60 ;write to interface card register low
XRA A
OUT 0x60 ;write to interface card register low
STA var_FF09
LXI H,var_F020
SHLD char_buff_ptr
JMP carriage_return_cursor
label_0345:
LDA var_FF22
MOV B,A
LXI H,var_F020
SHLD char_buff_ptr
DCR C
JNZ label_02CC
JMP return_from_int_subroutine ;return
;**************************************************************************************************
RST 7 ;????? warmboot
;**************************************************************************************************
err_printer_not_ready:
LXI B,var_printer_not_ready_string ;"printer not ready""
CALL cpy_str_to_screen_cursor_pos ;cpy_str_to_screen_cursor_pos("printer not ready")
MVI A,0x01
OUT 0x50
STA printer_not_ready_flag_FF0E
JMP return_from_int_subroutine ;return
;**************************************************************************************************
int_5_handler: ;what i think happens here is that we got an interrupt from an address match so now we need to latch the next byte
MVI A,0x61 ;UA5A Q=0 UA5B Q=1 set UC7B
OUT 0x78 ;10 write status to interface card
IN 0x78 ; read interface card status
ANI 0x40 ;check the card for status_d6
JNZ label_03FF ; do we have a byte sitting in our tx buffer still?
IN 0x68 ;read interface card buffer
MOV D,A
CPI 0x0A ;check for linefeed?
JZ label_038C
CPI 0xA5 ;is magic character 0xa5?
JZ label_03B4 ;stores the next byte & 0x3f into magic memory address var_FF0B
ANI 0xC0 ;high bits set (non printable??)
CPI 0xC0
JZ label_03CA ;looks like these are some kind of formatting code
CALL send_char_to_line_buff ; send_char_to_line_buff(D_reg)
JMP rearm_rx_buffer
label_038C:
LHLD char_buff_ptr
DCX H
MOV A,M
CPI 0x0D
JNZ send_crlf_to_screen
CALL send_char_to_line_buff ; send_char_to_line_buff(D_reg)
label_0399:
LXI H,var_F020
SHLD char_buff_ptr
MVI A,0x01
STA var_FF09
JMP ie_and_return_from_int_subroutine
send_crlf_to_screen:
MVI D,0x0D
CALL send_char_to_line_buff ; send_char_to_line_buff(D_reg)
MVI D,0x0A
CALL send_char_to_line_buff ; send_char_to_line_buff(D_reg)
JMP label_0399
label_03B4:
IN 0x78 ;read interface card status
RAR
CNC inc_and_store_error_counter
JNC label_03
CALL RST_3 ;clear error counter
IN 0x68 ;read interface card buffer
ANI 0x3F
STA var_FF0B
JMP ie_and_return_from_int_subroutine
label_03CA:
IN 0x78 ;read interface card status
RAR
CNC inc_and_store_error_counter
JNC label_03CA
CALL RST_3 ;clear error counter
IN 0x68 ;read interface card buffer
ANI 0x7F
STA var_FF0A
XRA A
STA var_cursor_line_FF11 ; zero the cursor position
JMP ie_and_return_from_int_subroutine
;**************************************************************************************************
send_char_to_line_buff: ; send_char_to_line_buff(D_reg)
LHLD char_buff_ptr ;load HL from ram
MOV M,D
INX H
MVI A,0xA8
CMP L
JZ append_crlf_to_buff
SHLD char_buff_ptr
RET
append_crlf_to_buff:
LXI H, var_F0A4
MVI M,0x0D
INX H
MVI M,0x0A
POP PSW
JMP label_0399
label_03FF:
IN 0x68 ;read interface card buffer
CPI 0xA5
JZ label_0411
LDA var_FF09
ORA A
JNZ label_0411
rearm_rx_buffer:
MVI A,0x02 ;reset status_d7
OUT 0x78 ;set status_d7 on the interface card, unlatch serial data?
label_0411:
IN 0x48 ;check keyboard status bits
MVI A,0x40
OUT 0x78 ;write status to interface card
JMP ie_and_return_from_int_subroutine
;**************************************************************************************************
sub_041A:
MOV D,M
INX H
MOV E,M
MVI B,0x00
MOV M,B
DCX H
MOV M,B
EI ;enable interrupts
RAL
JC label_0465 ;label_0465(A_reg)
;JMP filter_d_and_store_in_char_buff ; implicit
filter_d_and_store_in_char_buff: ;filter_d_and_store_in_char_buff(D_reg)
LHLD char_buff_cntr_FF00 ;load HL from ram
CALL translate_d ;D_reg = translate_d(D_reg)
MOV M,D ;store translated value
INX H
SHLD char_buff_cntr_FF00
MOV A,M
ORI 0x80
MOV M,A
;increment var_FFFA by two untill it reaches 0xffee, then set it back to (ffD0)
;circular buffer pointer?
cycle_var_FFFA:
LHLD var_FFFA ;load HL from ram
MOV A,L
CPI 0xEE
JNZ label_0442
LXI H,var_FFCE
label_0442:
INX H
INX H
SHLD var_FFFA
RET
;**************************************************************************************************
translate_d: ;D_reg = translate_d(D_reg)
MOV A,D
CPI 0x5F ;D == 0x5f?
JNZ d_does_not_match ;no
MVI D,0x1D ;yes D = 0x1d
RET
d_does_not_match:
CPI 0x5E ; d == 0x5e?
RNZ ;no
MVI D,0x1F
RET
;**************************************************************************************************
translate_d_type2: ; D_reg = translate_d_type2(A_reg)
CPI 0xB6
JNZ b6_handler
MVI D,0x1C
RET
b6_handler:
CPI 0xB8
RNZ
MVI D,0x1E
RET
;**************************************************************************************************
label_0465: ;label_0465(A_reg)
RAL
JC label_0497
MOV A,D
CPI 0xA9
JZ a9_handler
CPI 0xA7
JZ a7_handler
CPI 0xA2
JZ a2_handler
CPI 0xA0
JZ a0_handler
CPI 0xA3
JZ a3_handler
CPI 0xA4
JZ a4_handler
CALL translate_d_type2 ;D_reg = translate_d_type2(A_reg)
JZ filter_d_and_store_in_char_buff ;filter_d_and_store_in_char_buff(D_reg = translate_d_type2(A_reg))
JMP cycle_var_FFFA
;**************************************************************************************************
a4_handler:
CALL mask_display
JMP cycle_var_FFFA
;**************************************************************************************************
label_0497:
MOV A,E
RAL
JC label_0562
MOV A,D
ANI 0x1F
MOV D,A
CALL limit_char_buff_cntr
LXI H,0x0000
MOV L,D ; HL == (d_regvar & 0x1f)
PUSH D
LDA var_FF02
CALL sub_07AF
RAR
CC sub_07BA
XCHG
LXI H,var_C000_display_buff ;
DAD D ;add HL=0xc0000+DE
POP D
MOV C,E
XCHG
LHLD var_FFFC ;load HL from ram
XCHG
label_04BE:
MOV M,C
INX H
DCR E
JNZ label_04BE
JMP cycle_var_FFFA
;**************************************************************************************************
a9_handler:
MVI A,0x04
OUT 0x50
JMP cycle_var_FFFA
;**************************************************************************************************
a7_handler:
MVI A,0x01
OUT 0x50
JMP cycle_var_FFFA
;**************************************************************************************************
a2_handler: ;takes E as an argument \ function doesnt get called?
CALL limit_char_buff_cntr
MOV A,E
ANI 0x3F
LXI H,0x0000
MOV L,A
LDA var_FF02
CALL sub_07AF
RAR
CC sub_07BA
LXI B,var_C000_display_buff
DAD B
MOV B,H
MOV C,L
XCHG
LHLD var_FFFC ;load HL from ram
XCHG
DAD D
label_04F5:
LDAX B
MOV M,A
INX H
INX B
DCR E
JNZ label_04F5
JMP cycle_var_FFFA
;**************************************************************************************************
label_0500: