Electronic – arduino – 28C64 EEPROM Programming Using Arduino

I am working on a Z80 computer and needed to write data to an EEPROM. I am using the Xicor 28C64AP-25 chip (datasheet). I wrote a program for the Arduino Uno that writes data to the first 4 addresses and then reads the data back. Since I am only using the first three address pins, the rest are tied low. Here is my code, sorry if it seems too cluttered:

#define WE 11
#define OE 12
#define CE 13
#define NUM_ADDR 3
int DP[8] = {A0, A1, A2, A3, A4, A5, 2, 3};
int AP[] = {4, 5, 6};
byte data[] = {0x3E, 0xAA, 0xD3, 0x00, 0xC3, 0x00, 0x00};
void setupDataBus(int mode) {
  for (int i = 0; i < 8; i++) {
    pinMode(DP[i], mode);
  } 
}
void setupControlPins(int mode) {
  pinMode(WE, mode);
  pinMode(OE, mode);
  pinMode(CE, mode);
}
void setupAddressBus(int mode) {
  for (int i = 0; i < NUM_ADDR; i++) {
    pinMode(AP[i], mode);
  } 
}
void writeByte(int address, byte data) {
  setupDataBus(OUTPUT);
  setupAddressBus(OUTPUT);
  setupControlPins(OUTPUT);
  Serial.print("Write Byte: ");
  for (int b = 0; b < 7; b++) {
     digitalWrite(AP[b], bitRead(address, b));

  } 
  Serial.print(address, HEX);
  Serial.print(", ");
  Serial.print(data, HEX);
  Serial.println();
  delay(1);
  // Enable write
  digitalWrite(OE, HIGH);
  delay(1);
  digitalWrite(CE, LOW);
  delay(1);
  delay(10);
  for (int b = 0; b < 8; b++) {
    digitalWrite(DP[b], bitRead(data, b));
  }
  unsigned long time_i, time_f;
  time_i = micros();
  // Start write
  digitalWrite(WE, LOW);
  // End write
  digitalWrite(WE, HIGH);
  time= micros();
  Serial.println(time_f-time_i, DEC);
  delay(1);
  digitalWrite(OE, LOW);
  delay(1);
  digitalWrite(CE, HIGH);
  delay(1);

}
byte readByte(int address) {
  setupDataBus(INPUT);
  setupAddressBus(OUTPUT);
  setupControlPins(OUTPUT);
  byte val;
  digitalWrite(WE, HIGH);
  delay(1);
  digitalWrite(CE, HIGH);
  delay(1);
  digitalWrite(OE, HIGH);
  delay(1);
  Serial.print("Read Byte: ");
  for (int b = 0; b < 7; b++) {
     digitalWrite(AP[b], bitRead(address, b));
  }
  Serial.print(address, HEX);  
  Serial.print(", ");
  delay(1);
  digitalWrite(WE, HIGH);
  delay(1);
  digitalWrite(CE, LOW);
  delay(1);
  digitalWrite(OE, LOW);
  delay(1);

  for (int b = 0; b < 8; b++) {
     bitWrite(val, b, digitalRead(DP[b]));
  } 
  Serial.print(val, HEX);
  delay(1);
  digitalWrite(OE, HIGH);
  delay(1);
  digitalWrite(CE, HIGH);
  delay(1);
  digitalWrite(WE, HIGH);
  Serial.println();
  return val;
}
void setup() {
  setupDataBus(OUTPUT);
  setupAddressBus(OUTPUT);
  pinMode(WE, OUTPUT);
  pinMode(OE, OUTPUT);
  pinMode(CE, OUTPUT);
  Serial.begin(9600);
  }
  void loop() {
  // init
  digitalWrite(OE, HIGH);
  digitalWrite(CE, HIGH);
  digitalWrite(WE, HIGH);
  Serial.println("Initializing pins for write...");
  delay(1000);
  for (int i = 0; i < sizeof(data); i++) {
    writeByte(i, data[i]);
  }
  for (int i = 0; i < sizeof(data); i++) {
    readByte(i);
  }
  while(true);
}

All those delays are just to make sure I'm not going too fast for the EEPROM.
I can tell via some LEDs that the Arduino is outputing the right data onto the I/O pins of the EEPROM, but when I read the data back, all I get is 0xFF. Here is the serial output.

Initializing pins for write...
Write Byte: 0, 3E
/WE enable time: 12
Write Byte: 1, AA
/WE enable time: 12
Write Byte: 2, D3
/WE enable time: 12
Write Byte: 3, 0
/WE enable time: 12
Write Byte: 4, C3
/WE enable time: 12
Write Byte: 5, 0
/WE enable time: 12
Write Byte: 6, 0
/WE enable time: 12
Read Byte: 0, FF
Read Byte: 1, FF
Read Byte: 2, FF
Read Byte: 3, FF
Read Byte: 4, FF
Read Byte: 5, FF
Read Byte: 6, FF

I have tested an earlier version of the above program with a static RAM chip and everything works great. It just doesn't work with the EEPROM.

Any help would be much appreciated.