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Add ASM + fine tune a bit

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This commit is contained in:
Stefano Furiosi 2016-06-15 22:59:28 -07:00
parent 8031e9e254
commit e70361569c
6 changed files with 637 additions and 51 deletions
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16
ASM/basic_ops.asm Normal file
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@ -0,0 +1,16 @@
; TEST ADDRESSING MODES
; $FFFC and $FFFD - RESET PROGRAM COUNTER
processor 6502
org $FF00
lda #$00
sta $0000
loop
lda $0000
tax
inx
stx $0000
jmp loop

15
ASM/read_write.asm Normal file
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@ -0,0 +1,15 @@
; TEST ADDRESSING MODES
; $FFFC and $FFFD - RESET PROGRAM COUNTER
processor 6502
org $FF00
loop
lda #$AA
sta $0000
lda #$BB
sta $0001
nop
jmp loop

14
ASM/readonly_loop.asm Normal file
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@ -0,0 +1,14 @@
; TEST ADDRESSING MODES
; $FFFC and $FFFD - RESET PROGRAM COUNTER
processor 6502
org $FF00
loop
nop
nop
loop2
nop
jmp loop2

259
ASM/woz_monitor.asm Normal file
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@ -0,0 +1,259 @@
;-------------------------------------------------------------------------
;
; The WOZ Monitor for the Apple 1
; Written by Steve Wozniak 1976
;
;-------------------------------------------------------------------------
.CR 6502
.OR $FF00
.TF WOZMON.HEX,HEX,8
;-------------------------------------------------------------------------
; Memory declaration
;-------------------------------------------------------------------------
XAML .EQ $24 Last "opened" location Low
XAMH .EQ $25 Last "opened" location High
STL .EQ $26 Store address Low
STH .EQ $27 Store address High
L .EQ $28 Hex value parsing Low
H .EQ $29 Hex value parsing High
YSAV .EQ $2A Used to see if hex value is given
MODE .EQ $2B $00=XAM, $7F=STOR, $AE=BLOCK XAM
IN .EQ $0200,$027F Input buffer
KBD .EQ $D010 PIA.A keyboard input
KBDCR .EQ $D011 PIA.A keyboard control register
DSP .EQ $D012 PIA.B display output register
DSPCR .EQ $D013 PIA.B display control register
; KBD b7..b0 are inputs, b6..b0 is ASCII input, b7 is constant high
; Programmed to respond to low to high KBD strobe
; DSP b6..b0 are outputs, b7 is input
; CB2 goes low when data is written, returns high when CB1 goes high
; Interrupts are enabled, though not used. KBD can be jumpered to IRQ,
; whereas DSP can be jumpered to NMI.
;-------------------------------------------------------------------------
; Constants
;-------------------------------------------------------------------------
BS .EQ $DF Backspace key, arrow left key
CR .EQ $8D Carriage Return
ESC .EQ $9B ESC key
PROMPT .EQ "\" Prompt character
;-------------------------------------------------------------------------
; Let's get started
;
; Remark the RESET routine is only to be entered by asserting the RESET
; line of the system. This ensures that the data direction registers
; are selected.
;-------------------------------------------------------------------------
RESET CLD Clear decimal arithmetic mode
CLI
LDY #%0111.1111 Mask for DSP data direction reg
STY DSP (DDR mode is assumed after reset)
LDA #%1010.0111 KBD and DSP control register mask
STA KBDCR Enable interrupts, set CA1, CB1 for
STA DSPCR positive edge sense/output mode.
; Program falls through to the GETLINE routine to save some program bytes
; Please note that Y still holds $7F, which will cause an automatic Escape
;-------------------------------------------------------------------------
; The GETLINE process
;-------------------------------------------------------------------------
NOTCR CMP #BS Backspace key?
BEQ BACKSPACE Yes
CMP #ESC ESC?
BEQ ESCAPE Yes
INY Advance text index
BPL NEXTCHAR Auto ESC if line longer than 127
ESCAPE LDA #PROMPT Print prompt character
JSR ECHO Output it.
GETLINE LDA #CR Send CR
JSR ECHO
LDY #0+1 Start a new input line
BACKSPACE DEY Backup text index
BMI GETLINE Oops, line's empty, reinitialize
NEXTCHAR LDA KBDCR Wait for key press
BPL NEXTCHAR No key yet!
LDA KBD Load character. B7 should be '1'
STA IN,Y Add to text buffer
JSR ECHO Display character
CMP #CR
BNE NOTCR It's not CR!
; Line received, now let's parse it
LDY #-1 Reset text index
LDA #0 Default mode is XAM
TAX X=0
SETSTOR ASL Leaves $7B if setting STOR mode
SETMODE STA MODE Set mode flags
BLSKIP INY Advance text index
NEXTITEM LDA IN,Y Get character
CMP #CR
BEQ GETLINE We're done if it's CR!
CMP #"."
BCC BLSKIP Ignore everything below "."!
BEQ SETMODE Set BLOCK XAM mode ("." = $AE)
CMP #":"
BEQ SETSTOR Set STOR mode! $BA will become $7B
CMP #"R"
BEQ RUN Run the program! Forget the rest
STX L Clear input value (X=0)
STX H
STY YSAV Save Y for comparison
; Here we're trying to parse a new hex value
NEXTHEX LDA IN,Y Get character for hex test
EOR #$B0 Map digits to 0-9
CMP #9+1 Is it a decimal digit?
BCC DIG Yes!
ADC #$88 Map letter "A"-"F" to $FA-FF
CMP #$FA Hex letter?
BCC NOTHEX No! Character not hex
DIG ASL
ASL Hex digit to MSD of A
ASL
ASL
LDX #4 Shift count
HEXSHIFT ASL Hex digit left, MSB to carry
ROL L Rotate into LSD
ROL H Rotate into MSD's
DEX Done 4 shifts?
BNE HEXSHIFT No, loop
INY Advance text index
BNE NEXTHEX Always taken
NOTHEX CPY YSAV Was at least 1 hex digit given?
BEQ ESCAPE No! Ignore all, start from scratch
BIT MODE Test MODE byte
BVC NOTSTOR B6=0 is STOR, 1 is XAM or BLOCK XAM
; STOR mode, save LSD of new hex byte
LDA L LSD's of hex data
STA (STL,X) Store current 'store index'(X=0)
INC STL Increment store index.
BNE NEXTITEM No carry!
INC STH Add carry to 'store index' high
TONEXTITEM JMP NEXTITEM Get next command item.
;-------------------------------------------------------------------------
; RUN user's program from last opened location
;-------------------------------------------------------------------------
RUN JMP (XAML) Run user's program
;-------------------------------------------------------------------------
; We're not in Store mode
;-------------------------------------------------------------------------
NOTSTOR BMI XAMNEXT B7 = 0 for XAM, 1 for BLOCK XAM
; We're in XAM mode now
LDX #2 Copy 2 bytes
SETADR LDA L-1,X Copy hex data to
STA STL-1,X 'store index'
STA XAML-1,X and to 'XAM index'
DEX Next of 2 bytes
BNE SETADR Loop unless X = 0
; Print address and data from this address, fall through next BNE.
NXTPRNT BNE PRDATA NE means no address to print
LDA #CR Print CR first
JSR ECHO
LDA XAMH Output high-order byte of address
JSR PRBYTE
LDA XAML Output low-order byte of address
JSR PRBYTE
LDA #":" Print colon
JSR ECHO
PRDATA LDA #" " Print space
JSR ECHO
LDA (XAML,X) Get data from address (X=0)
JSR PRBYTE Output it in hex format
XAMNEXT STX MODE 0 -> MODE (XAM mode).
LDA XAML See if there's more to print
CMP L
LDA XAMH
SBC H
BCS TONEXTITEM Not less! No more data to output
INC XAML Increment 'examine index'
BNE MOD8CHK No carry!
INC XAMH
MOD8CHK LDA XAML If address MOD 8 = 0 start new line
AND #%0000.0111
BPL NXTPRNT Always taken.
;-------------------------------------------------------------------------
; Subroutine to print a byte in A in hex form (destructive)
;-------------------------------------------------------------------------
PRBYTE PHA Save A for LSD
LSR
LSR
LSR MSD to LSD position
LSR
JSR PRHEX Output hex digit
PLA Restore A
; Fall through to print hex routine
;-------------------------------------------------------------------------
; Subroutine to print a hexadecimal digit
;-------------------------------------------------------------------------
PRHEX AND #%0000.1111 Mask LSD for hex print
ORA #"0" Add "0"
CMP #"9"+1 Is it a decimal digit?
BCC ECHO Yes! output it
ADC #6 Add offset for letter A-F
; Fall through to print routine
;-------------------------------------------------------------------------
; Subroutine to print a character to the terminal
;-------------------------------------------------------------------------
ECHO BIT DSP DA bit (B7) cleared yet?
BMI ECHO No! Wait for display ready
STA DSP Output character. Sets DA
RTS
;-------------------------------------------------------------------------
; Vector area
;-------------------------------------------------------------------------
.DA $0000 Unused, what a pity
NMI_VEC .DA $0F00 NMI vector
RESET_VEC .DA RESET RESET vector
IRQ_VEC .DA $0000 IRQ vector
;-------------------------------------------------------------------------
.LI OFF

258
ASM/woz_monitor_dasm.asm Normal file
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@ -0,0 +1,258 @@
;-------------------------------------------------------------------------
;
; The WOZ Monitor for the Apple 1
; Written by Steve Wozniak 1976
;
;-------------------------------------------------------------------------
processor 6502
org $FF00
;-------------------------------------------------------------------------
; Memory declaration
;-------------------------------------------------------------------------
XAML .EQ $24 Last "opened" location Low
XAMH .EQ $25 Last "opened" location High
STL .EQ $26 Store address Low
STH .EQ $27 Store address High
L .EQ $28 Hex value parsing Low
H .EQ $29 Hex value parsing High
YSAV .EQ $2A Used to see if hex value is given
MODE .EQ $2B $00=XAM, $7F=STOR, $AE=BLOCK XAM
IN .EQ $0200,$027F Input buffer
KBD .EQ $D010 PIA.A keyboard input
KBDCR .EQ $D011 PIA.A keyboard control register
DSP .EQ $D012 PIA.B display output register
DSPCR .EQ $D013 PIA.B display control register
; KBD b7..b0 are inputs, b6..b0 is ASCII input, b7 is constant high
; Programmed to respond to low to high KBD strobe
; DSP b6..b0 are outputs, b7 is input
; CB2 goes low when data is written, returns high when CB1 goes high
; Interrupts are enabled, though not used. KBD can be jumpered to IRQ,
; whereas DSP can be jumpered to NMI.
;-------------------------------------------------------------------------
; Constants
;-------------------------------------------------------------------------
BS .EQ $DF Backspace key, arrow left key
CR .EQ $8D Carriage Return
ESC .EQ $9B ESC key
PROMPT .EQ "\" Prompt character
;-------------------------------------------------------------------------
; Let's get started
;
; Remark the RESET routine is only to be entered by asserting the RESET
; line of the system. This ensures that the data direction registers
; are selected.
;-------------------------------------------------------------------------
RESET CLD Clear decimal arithmetic mode
CLI
LDY #%0111.1111 Mask for DSP data direction reg
STY DSP (DDR mode is assumed after reset)
LDA #%1010.0111 KBD and DSP control register mask
STA KBDCR Enable interrupts, set CA1, CB1 for
STA DSPCR positive edge sense/output mode.
; Program falls through to the GETLINE routine to save some program bytes
; Please note that Y still holds $7F, which will cause an automatic Escape
;-------------------------------------------------------------------------
; The GETLINE process
;-------------------------------------------------------------------------
NOTCR CMP #BS Backspace key?
BEQ BACKSPACE Yes
CMP #ESC ESC?
BEQ ESCAPE Yes
INY Advance text index
BPL NEXTCHAR Auto ESC if line longer than 127
ESCAPE LDA #PROMPT Print prompt character
JSR ECHO Output it.
GETLINE LDA #CR Send CR
JSR ECHO
LDY #0+1 Start a new input line
BACKSPACE DEY Backup text index
BMI GETLINE Oops, line's empty, reinitialize
NEXTCHAR LDA KBDCR Wait for key press
BPL NEXTCHAR No key yet!
LDA KBD Load character. B7 should be '1'
STA IN,Y Add to text buffer
JSR ECHO Display character
CMP #CR
BNE NOTCR It's not CR!
; Line received, now let's parse it
LDY #-1 Reset text index
LDA #0 Default mode is XAM
TAX X=0
SETSTOR ASL Leaves $7B if setting STOR mode
SETMODE STA MODE Set mode flags
BLSKIP INY Advance text index
NEXTITEM LDA IN,Y Get character
CMP #CR
BEQ GETLINE We're done if it's CR!
CMP #"."
BCC BLSKIP Ignore everything below "."!
BEQ SETMODE Set BLOCK XAM mode ("." = $AE)
CMP #":"
BEQ SETSTOR Set STOR mode! $BA will become $7B
CMP #"R"
BEQ RUN Run the program! Forget the rest
STX L Clear input value (X=0)
STX H
STY YSAV Save Y for comparison
; Here we're trying to parse a new hex value
NEXTHEX LDA IN,Y Get character for hex test
EOR #$B0 Map digits to 0-9
CMP #9+1 Is it a decimal digit?
BCC DIG Yes!
ADC #$88 Map letter "A"-"F" to $FA-FF
CMP #$FA Hex letter?
BCC NOTHEX No! Character not hex
DIG ASL
ASL Hex digit to MSD of A
ASL
ASL
LDX #4 Shift count
HEXSHIFT ASL Hex digit left, MSB to carry
ROL L Rotate into LSD
ROL H Rotate into MSD's
DEX Done 4 shifts?
BNE HEXSHIFT No, loop
INY Advance text index
BNE NEXTHEX Always taken
NOTHEX CPY YSAV Was at least 1 hex digit given?
BEQ ESCAPE No! Ignore all, start from scratch
BIT MODE Test MODE byte
BVC NOTSTOR B6=0 is STOR, 1 is XAM or BLOCK XAM
; STOR mode, save LSD of new hex byte
LDA L LSD's of hex data
STA (STL,X) Store current 'store index'(X=0)
INC STL Increment store index.
BNE NEXTITEM No carry!
INC STH Add carry to 'store index' high
TONEXTITEM JMP NEXTITEM Get next command item.
;-------------------------------------------------------------------------
; RUN user's program from last opened location
;-------------------------------------------------------------------------
RUN JMP (XAML) Run user's program
;-------------------------------------------------------------------------
; We're not in Store mode
;-------------------------------------------------------------------------
NOTSTOR BMI XAMNEXT B7 = 0 for XAM, 1 for BLOCK XAM
; We're in XAM mode now
LDX #2 Copy 2 bytes
SETADR LDA L-1,X Copy hex data to
STA STL-1,X 'store index'
STA XAML-1,X and to 'XAM index'
DEX Next of 2 bytes
BNE SETADR Loop unless X = 0
; Print address and data from this address, fall through next BNE.
NXTPRNT BNE PRDATA NE means no address to print
LDA #CR Print CR first
JSR ECHO
LDA XAMH Output high-order byte of address
JSR PRBYTE
LDA XAML Output low-order byte of address
JSR PRBYTE
LDA #":" Print colon
JSR ECHO
PRDATA LDA #" " Print space
JSR ECHO
LDA (XAML,X) Get data from address (X=0)
JSR PRBYTE Output it in hex format
XAMNEXT STX MODE 0 -> MODE (XAM mode).
LDA XAML See if there's more to print
CMP L
LDA XAMH
SBC H
BCS TONEXTITEM Not less! No more data to output
INC XAML Increment 'examine index'
BNE MOD8CHK No carry!
INC XAMH
MOD8CHK LDA XAML If address MOD 8 = 0 start new line
AND #%0000.0111
BPL NXTPRNT Always taken.
;-------------------------------------------------------------------------
; Subroutine to print a byte in A in hex form (destructive)
;-------------------------------------------------------------------------
PRBYTE PHA Save A for LSD
LSR
LSR
LSR MSD to LSD position
LSR
JSR PRHEX Output hex digit
PLA Restore A
; Fall through to print hex routine
;-------------------------------------------------------------------------
; Subroutine to print a hexadecimal digit
;-------------------------------------------------------------------------
PRHEX AND #%0000.1111 Mask LSD for hex print
ORA #"0" Add "0"
CMP #"9"+1 Is it a decimal digit?
BCC ECHO Yes! output it
ADC #6 Add offset for letter A-F
; Fall through to print routine
;-------------------------------------------------------------------------
; Subroutine to print a character to the terminal
;-------------------------------------------------------------------------
ECHO BIT DSP DA bit (B7) cleared yet?
BMI ECHO No! Wait for display ready
STA DSP Output character. Sets DA
RTS
;-------------------------------------------------------------------------
; Vector area
;-------------------------------------------------------------------------
.DA $0000 Unused, what a pity
NMI_VEC .DA $0F00 NMI vector
RESET_VEC .DA RESET RESET vector
IRQ_VEC .DA $0000 IRQ vector
;-------------------------------------------------------------------------
.LI OFF

100
src/main.cpp
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@ -3,50 +3,60 @@
#define CHECK_BIT(var,pos) ((var) & (1<<(pos))) #define CHECK_BIT(var,pos) ((var) & (1<<(pos)))
const int CLOCK_PIN = 52; const int SERIAL_SPEED = 115200; // Arduino Serial Speed
const int RW_PIN = 53;
const int CLOCK_DELAY = 100; const int CLOCK_PIN = 52; // TO 6502 CLOCK
const int RW_PIN = 53; // TO 6502 R/W
const int CLOCK_DELAY = 1; // HIGH / LOW CLOCK STATE DELAY
const int NUM_ADDR_PINS = 16; const int NUM_ADDR_PINS = 16;
const int NUM_DATA_PINS = 8; const int NUM_DATA_PINS = 8;
const int ADDRESS_PINS[] = {44,45,2,3,4,5,6,7,8,9,10,11,12,13,46,47}; const int ADDRESS_PINS[] = {44,45,2,3,4,5,6,7,8,9,10,11,12,13,46,47}; // TO ADDRESS PIN 1-15 6502
const int DATA_PINS[] = {30,31,32,33,34,35,36,37}; const int DATA_PINS[] = {30,31,32,33,34,35,36,37}; // TO DATA BUS PIN 0-7 6502
const unsigned int ROM_ADDR = 0xFF00; const unsigned int ROM_ADDR = 0xFF00; // ROM
const unsigned int RAM_BANK1_ADDR = 0x0000; const unsigned int RAM_BANK1_ADDR = 0x0000; // RAM
const unsigned int RAM_BANK2_ADDR = 0xE000; const unsigned int RAM_BANK2_ADDR = 0xE000; // EXTENDED RAM
const unsigned int PIA_ADDR = 0xD000;
const unsigned int XAML = 0x24; const unsigned int XAML = 0x24; // Last "opened" location Low
const unsigned int XAMH = 0x25; const unsigned int XAMH = 0x25; // Last "opened" location High
const unsigned int STL = 0x26; const unsigned int STL = 0x26; // Store address Low
const unsigned int STH = 0x27; const unsigned int STH = 0x27; // Store address High
const unsigned int L = 0x28; const unsigned int L = 0x28; // Hex value parsing Low
const unsigned int H = 0x29; const unsigned int H = 0x29; // Hex value parsing High
const unsigned int YSAV = 0x2A; const unsigned int YSAV = 0x2A; // Used to see if hex value is given
const unsigned int MODE = 0x2B; const unsigned int MODE = 0x2B; // $00=XAM, $7F=STOR, $AE=BLOCK XAM
const unsigned int IN = 0x200; // Input buffer ($0200,$027F)
const unsigned int IN = 0x200;
const int RAM_BANK_1_SIZE = 4096; const int RAM_BANK_1_SIZE = 4096;
const int RAM_BANK_2_SIZE = 4096; const int RAM_BANK_2_SIZE = 4096;
unsigned char RAM_BANK_1[RAM_BANK_1_SIZE]; unsigned char RAM_BANK_1[RAM_BANK_1_SIZE];
unsigned int address; // PIA MAPPING 6821
unsigned char bus_data=0; const unsigned int PIA_ADDR = 0xD000; // PIA 6821 ADDR BASE SPACE
int rw_state = HIGH; const unsigned int KBD_ADDR = 0xD010; // Keyb Char - B7 High on keypress
const unsigned int KBDCR_ADDR = 0xD011; // Keyb Status - B7 High on keypress / Low when ready
const unsigned int KBD_ADDR = 0xD010; const unsigned int DSP_ADDR = 0xD012; // DSP Char
const unsigned int KBDCR_ADDR = 0xD011; const unsigned int DSPCR_ADDR = 0xD013; // DSP Status - B7 Low if VIDEO ready
const unsigned int DSP_ADDR = 0xD012;
const unsigned int DSPCR_ADDR = 0xD013;
unsigned char KBD = 0; unsigned char KBD = 0;
unsigned char KBDCR = 0; unsigned char KBDCR = 0;
unsigned char DSP = 0; unsigned char DSP = 0;
unsigned char DSPCR = 0; unsigned char DSPCR = 0;
const unsigned char BS = 0xDF; // Backspace key, arrow left key (B7 High)
const unsigned char CR = 0x8D; // Carriage Return (B7 High)
const unsigned char ESC = 0x9B; // ESC key (B7 High)
unsigned int address; // Current address (from 6502)
unsigned char bus_data; // Data Bus value (from 6502)
int rw_state; // Current R/W state (from 6502)
unsigned int pre_address; // Current address (from 6502)
unsigned char pre_bus_data; // Data Bus value (from 6502)
int pre_rw_state; // Current R/W state (from 6502)
void setupAddressPins() { void setupAddressPins() {
for (int i = 0; i < NUM_ADDR_PINS; ++i) { for (int i = 0; i < NUM_ADDR_PINS; ++i) {
pinMode(ADDRESS_PINS[i], INPUT); pinMode(ADDRESS_PINS[i], INPUT);
@ -82,19 +92,23 @@ void handleRWState() {
if (rw_state != curent_rw_state) { if (rw_state != curent_rw_state) {
rw_state=curent_rw_state; rw_state=curent_rw_state;
if (rw_state) { if (rw_state) {
// State HIGH - WRITE TO 6502 Data Bus
busMode(OUTPUT); busMode(OUTPUT);
} else { } else {
// State LOW - READ FROM 6502 Data Bus
busMode(INPUT); busMode(INPUT);
} }
} }
} }
// Send a byte to the 6502 DATA BUS
void byteToDataBus(unsigned char data) { void byteToDataBus(unsigned char data) {
for (int i = 0; i < NUM_DATA_PINS; i++) { for (int i = 0; i < NUM_DATA_PINS; i++) {
digitalWrite(DATA_PINS[i], CHECK_BIT(data, i)); digitalWrite(DATA_PINS[i], CHECK_BIT(data, i));
} }
} }
// READ FROM DATA BUS - STORE AT RELATED ADDRESS
void readFromDataBus() { void readFromDataBus() {
readData(); readData();
@ -117,12 +131,14 @@ void readFromDataBus() {
break; break;
case DSP_ADDR: case DSP_ADDR:
DSP = bus_data; DSP = bus_data;
if (DSP == 0x8D) { if (DSP == CR) {
// Simulate CR
Serial.write('\r'); Serial.write('\r');
Serial.write('\n'); Serial.write('\n');
} else { } else {
Serial.write(DSP & 0x7F); Serial.write(DSP & 0x7F);
} }
// Display Ready - clear B7
bitClear(DSP, 7); bitClear(DSP, 7);
break; break;
case DSPCR_ADDR: case DSPCR_ADDR:
@ -133,6 +149,7 @@ void readFromDataBus() {
} }
} }
// WRITE FROM DATA BUS A BYTE FROM RELATED ADDRESS
void writeToDataBus() { void writeToDataBus() {
unsigned char val=0; unsigned char val=0;
@ -147,10 +164,11 @@ void writeToDataBus() {
val=ROM[address-ROM_ADDR]; val=ROM[address-ROM_ADDR];
break; break;
case 0xD: case 0xD:
// 6821 // PIA 6821
switch (address) { switch (address) {
case KBD_ADDR: case KBD_ADDR:
val=KBD; val=KBD;
// We'v read the char, clear B7
bitClear(KBDCR, 7); bitClear(KBDCR, 7);
break; break;
case KBDCR_ADDR: case KBDCR_ADDR:
@ -178,19 +196,24 @@ void handleKeyboard() {
// KEYBOARD INPUT // KEYBOARD INPUT
if (Serial.available() > 0) { if (Serial.available() > 0) {
char tempKBD = Serial.read(); char tempKBD = Serial.read();
switch (tempKBD) { switch (tempKBD) {
case 0xA: case 0xA:
// Not expected from KEYB
// Just ignore
return; return;
break; break;
case 0xD: case 0xD:
// CR
tempKBD = 0x0D; tempKBD = 0x0D;
break; break;
} }
KBD = tempKBD; KBD = tempKBD;
// Step B7 on KBD so that the code know a new char is in
bitSet(KBD, 7); bitSet(KBD, 7);
bitSet(KBDCR, 7); bitSet(KBDCR, 7);
} }
} }
@ -199,7 +222,7 @@ void setup() {
pinMode(RW_PIN, INPUT); pinMode(RW_PIN, INPUT);
setupAddressPins(); setupAddressPins();
busMode(OUTPUT); busMode(OUTPUT);
Serial.begin (115200); Serial.begin(SERIAL_SPEED);
Serial.println("----------------------------"); Serial.println("----------------------------");
Serial.println("APPLE 1 REPLICA by =STID="); Serial.println("APPLE 1 REPLICA by =STID=");
@ -218,7 +241,6 @@ void setup() {
} }
void loop () { void loop () {
// LOW CLOCK // LOW CLOCK
digitalWrite(CLOCK_PIN, LOW); digitalWrite(CLOCK_PIN, LOW);
delayMicroseconds(CLOCK_DELAY); delayMicroseconds(CLOCK_DELAY);
@ -234,16 +256,18 @@ void loop () {
readAddress(); readAddress();
// READ OR WRITE TO BUS? // READ OR WRITE TO BUS?
if (rw_state) {
writeToDataBus(); if (pre_address != address || pre_rw_state != rw_state) {
rw_state ? writeToDataBus() : readFromDataBus();
} else { } else {
readFromDataBus(); pre_address = address;
pre_rw_state = rw_state;
} }
handleKeyboard(); handleKeyboard();
} }
// WOZ TEST // WOZ TEST (As on the Apple 1 Manual)
// 0:A9 9 AA 20 EF FF E8 8A 4C 2 0 // 0:A9 9 AA 20 EF FF E8 8A 4C 2 0
// HELLO WORLD // HELLO WORLD