From f5b2a9241a32402b29d56af634212096fe9b9edf Mon Sep 17 00:00:00 2001
From: Tom Nisbet <t.talk@nisbethome.com>
Date: Sat, 22 Dec 2018 09:59:41 -0500
Subject: [PATCH] Fix address error with 8755A burning

---
 TommyPROM/PromDevice8755A.cpp |  3 +--
 TommyPROM/TommyPROM.ino       | 17 +++++++++++++++--
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/TommyPROM/PromDevice8755A.cpp b/TommyPROM/PromDevice8755A.cpp
index b6ef95e..2ad82ce 100644
--- a/TommyPROM/PromDevice8755A.cpp
+++ b/TommyPROM/PromDevice8755A.cpp
@@ -54,6 +54,7 @@ void PromDevice8755A::begin()
 // address lines.  The read and burn code will take care of the ALE line
 void PromDevice8755A::setAddress(word address)
 {
+    setDataBusMode(OUTPUT);
     writeDataBus(byte(address & 0xff));
     digitalWrite(AD8, address & 0x100  ? HIGH : LOW);
     digitalWrite(AD9, address & 0x200  ? HIGH : LOW);
@@ -70,14 +71,12 @@ byte PromDevice8755A::readByte(word address)
 
 	// Put the address on the bus and latch it with ALE
     digitalWrite(CE2, HIGH);
-    setDataBusMode(OUTPUT);
     setAddress(address);
 	digitalWrite(ALE, HIGH);
 	digitalWrite(ALE, LOW);
 
 	// Read a byte
     setDataBusMode(INPUT);
-    setAddress(0xff);
     digitalWrite(RD, LOW);
     delayMicroseconds(1);
     data = readDataBus();
diff --git a/TommyPROM/TommyPROM.ino b/TommyPROM/TommyPROM.ino
index 160cf63..848aa4c 100644
--- a/TommyPROM/TommyPROM.ino
+++ b/TommyPROM/TommyPROM.ino
@@ -29,6 +29,17 @@ CmdStatus cmdStatus;
 //   Data polling supported
 PromDevice28C  prom(32 * 1024L, 64, 10, true);
 
+#elif defined(PROM_IS_27)
+// Define a device for a 2764 EPROM with the following parameters:
+//   8K byte device capacity
+//   1000us (1ms) write pulse
+//   15 write attempts
+//   4x overwrite pulse
+PromDevice27  prom(8 * 1024L, 1000L, 15, 4); // 2764 with SEEQ intelligent programming
+//PromDevice27  prom(32 * 1024L, 1000L, 25, 3); // 27C256 with SEEQ intelligent programming
+//PromDevice27  prom(2 * 1024L, 50000L, 1, 0); // 2716 with single 50ms write
+//PromDevice27  prom(64 * 1024L, 100L, 11, 0); // 27C040 with Atmel rapid programming
+
 #elif defined(PROM_IS_8755A)
 // Define a device for an 8755A.  This has a fixed size of 2K and no
 // other parameters.
@@ -490,7 +501,7 @@ void zapTest(word start)
         return;
     }
 
-    delayMicroseconds(10000);
+    delay(100);
     for (int ix = 0; ix < sizeof(testData); ix++)
     {
         byte val = prom.readData(start + ix);
@@ -529,6 +540,7 @@ void setup()
 * executing read or write requestes.
 **/
 
+/* 8085 Test programs
 byte ledTest[] =
 {
     0xc3, 0x03, 0x80, 0x3e, 0xc0, 0x30, 0x3e, 0xff,
@@ -545,6 +557,7 @@ byte charTest[] =
     0x3e, 0x40, 0x30, 0x3e, 0xc0, 0x30, 0x3e, 0x40, 0x30, 0x21, 0xff, 0xff,
     0x2d, 0xc2, 0x30, 0x80, 0x25, 0xc2, 0x30, 0x80, 0xc3, 0x03, 0x80
 };
+*/
 
 word start = 0;
 word end = 0xff;
@@ -644,7 +657,7 @@ void loop()
         break;
 
     default:
-        Serial.println(F("TommyPROM 1.5\n"));
+        Serial.println(F("TommyPROM 1.6\n"));
         Serial.println(F("Valid commands are:"));
         Serial.println(F("  Cssss eeee    - Compute checksum from device"));
         Serial.println(F("  Dssss eeee    - Dump bytes from device to terminal"));