Bits from Ben

This commit is contained in:
Paul Warren 2019-12-16 19:44:22 +11:00
commit 5e42e2a80c
2 changed files with 69 additions and 0 deletions

45
6502-monitor.ino Normal file
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const char ADDR[] = {22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52};
const char DATA[] = {39, 41, 43, 45, 47, 49, 51, 53};
#define CLOCK 2
#define READ_WRITE 3
void setup() {
for (int n = 0; n < 16; n += 1) {
pinMode(ADDR[n], INPUT);
}
for (int n = 0; n < 8; n += 1) {
pinMode(DATA[n], INPUT);
}
pinMode(CLOCK, INPUT);
pinMode(READ_WRITE, INPUT);
attachInterrupt(digitalPinToInterrupt(CLOCK), onClock, RISING);
Serial.begin(57600);
}
void onClock() {
char output[15];
unsigned int address = 0;
for (int n = 0; n < 16; n += 1) {
int bit = digitalRead(ADDR[n]) ? 1 : 0;
Serial.print(bit);
address = (address << 1) + bit;
}
Serial.print(" ");
unsigned int data = 0;
for (int n = 0; n < 8; n += 1) {
int bit = digitalRead(DATA[n]) ? 1 : 0;
Serial.print(bit);
data = (data << 1) + bit;
}
sprintf(output, " %04x %c %02x", address, digitalRead(READ_WRITE) ? 'r' : 'W', data);
Serial.println(output);
}
void loop() {
}

24
makerom.py Normal file
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#
# Please see this video for details:
# https://www.youtube.com/watch?v=yl8vPW5hydQ
#
code = bytearray([
0xa9, 0xff, # lda #$ff
0x8d, 0x02, 0x60, # sta $6002
0xa9, 0x55, # lda #$55
0x8d, 0x00, 0x60, # sta $6000
0xa9, 0xaa, # lda #$aa
0x8d, 0x00, 0x60, # sta $6000
0x4c, 0x05, 0x80, # jmp $8005
])
rom = code + bytearray([0xea] * (32768 - len(code)))
rom[0x7ffc] = 0x00
rom[0x7ffd] = 0x80
with open("rom.bin", "wb") as out_file:
out_file.write(rom)