Proof of concept using the great work of gusmanb
https://github.com/gusmanb/logicanalyzer
Next to do : Make some PCB’s

Below, a screenshot with I2C protocol decoding!
I’m using this fast level shifter.
Proof of concept using the great work of gusmanb
https://github.com/gusmanb/logicanalyzer
Next to do : Make some PCB’s

Below, a screenshot with I2C protocol decoding!
I’m using this fast level shifter.
UPDATE 20240927 PCBs are in
While testing on a breadboard is fast, I still want my 68000 on PCBs.
Breadboards are nice for testing, and I use them in the design stage.
But they will fail in the end.
Loose wires, oxidated contacts and alike.
So when I was testing using breadboard, I drew the schematics in KiCad.
I wanted to use Eurocards for this one. If I divide the whole system in system blocks, I can exchange and experiment parts.
(My 6502 uses another method to connect different cards)
I wrote about Eurocards in the past.
So I’m using the VMEbus standard for my new design.
(Using the recently bought book I mentioned)
Backplane design is done. And currently being autorouted.
PowerLeds for 5 and 12V. On/Off switch and MOLEX power connector.
Kicad sources will be uploaded
In the past, I dumped my old eurocards and even a nice case I had.
UPDATE 20240927 PCBs are in

Was planning to use this as input matrix
Even drew some graphics using inkscape
But it is too large.
Check out https://github.com/MothSynths/MothOS
Going to test if we can use the full 16Mb Flash and 8Mb PSRam
Next to do, remove DuPont wires, and design a 3d printed case.
Saw a cool game a while ago, and found some old code.
There was no schematic, so I had to reverse engineer it using the Arduino code.
This one uses a Micro Pro.
Build a working version, now I can use this as base to create other games.
But first i’m going to rebuild it so it can use Wifi and uses a Lipo Battery. Making it usable without wires.
Next to do:
But it works! Many iterations .. almost perfect

Record player is going to be re-printed at a higher quality.
Updated python client (see previous posts)
import paho.mqtt.client as mqtt
import urllib.request
from time import sleep
def on_connect(client, userdata, flags, rc): # The callback for when the client connects to the broker
print("Connected with result code {0}".format(str(rc)))
client.subscribe("spotify/rfid/idlms")
client.subscribe("spotify/rfid/but1")
client.subscribe("spotify/rfid/but2")
client.subscribe("spotify/rfid/arm")
def on_message(client, userdata, msg): # The callback for when a PUBLISH message is received from the server.
print("Message received-> " + msg.topic + " " + str(msg.payload)) # Print a received msg
if msg.topic == "spotify/rfid/idlms":
urllib.request.urlopen("http://LMS-SERVER-IP:9000/anyurl?p0=playlistcontrol&p1=album_id:" + msg.payload.decode() + "&p2=cmd:load&player=00:04:20:16:d9:04")
if msg.topic == "spotify/rfid/but1":
urllib.request.urlopen("http://LMS-SERVER-IP:9000/anyurl?p0=pause&player=00:04:20:16:d9:04")
sleep(1)
if msg.topic == "spotify/rfid/but2":
urllib.request.urlopen("http://LMS-SERVER-IP:9000/anyurl?p0=pause&pt=1&player=00:04:20:16:d9:04")
sleep(1)
if msg.topic == "spotify/rfid/arm":
urllib.request.urlopen("http://LMS-SERVER-IP:9000/status.html?p0=button&p1=jump_fwd&player=00:04:20:16:d9:04")
sleep(1)
client = mqtt.Client("lmsclient") # Create instance of client with client ID “digi_mqtt_test”
client.on_connect = on_connect # Define callback function for successful connection
client.on_message = on_message # Define callback function for receipt of a message
client.connect('MQTTSERVER', 1883)
client.loop_forever() # Start daemon
Wemos INO file
#include <Arduino.h>
#include <SPI.h>
#include <MFRC522.h>
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>
#define SS_PIN 15
#define RST_PIN 0
const int buttonPin1 = D1;
const int buttonPin2 = D2;
int buttonState1 = 0;
int buttonState2 = 0;
MFRC522 mfrc522(SS_PIN, RST_PIN);
MFRC522::StatusCode status; //variable to get card status
byte buffer[18]; //data transfer buffer (16+2 bytes data+CRC)
byte size = sizeof(buffer);
uint8_t pageAddr = 0x06; //In this example we will write/read 16 bytes (page 6,7,8 and 9).
//Ultraligth mem = 16 pages. 4 bytes per page.
//Pages 0 to 4 are for special functions.
unsigned long cardId = 0;
WiFiClient net;
PubSubClient client(net);
const char* mqtt_server = "MQTTBROKER";
const char* ssid = "MYSSID";
const char* password = "MYWIFIPASWORD";
String topicStr = "";
byte buffer2[8];
boolean Rflag=false;
int r_len;
char payload[5];
byte value[5];
void setup() {
Serial.begin(9600);
pinMode(buttonPin1, INPUT_PULLUP);
pinMode(buttonPin2, INPUT_PULLUP );
SPI.begin();
mfrc522.PCD_Init();
WiFi.mode(WIFI_AP_STA);
WiFi.begin(ssid, password);
client.setServer(mqtt_server, 1883);
delay(100);
client.setCallback(callback);
delay(100);
client.subscribe("spotify/rfid/in/#");
}
void reconnect() {
while (WiFi.waitForConnectResult() != WL_CONNECTED) {
}
while (!client.connected()) {
String clientId = "rfid-";
clientId += String(random(0xffff), HEX);
if (!client.connect(clientId.c_str(), "rfidclient", "...")) {
delay(5000);
}
}
client.subscribe("spotify/rfid/in/#");
}
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print(F("Called"));
Rflag=true; //will use in main loop
r_len=length; //will use in main loop
int j=0;
for (j;j<length;j++) {
buffer2[j]=payload[j];
//Serial.print((char)payload[j]);
}
if (r_len < 3) {
Rflag=false;
Serial.print(F("Set false"));
}
buffer2[j]='\0'; //terminate string
}
void loop() {
if (!client.connected()) {
reconnect();
}
buttonState1 = digitalRead(buttonPin1);
//Serial.print(buttonState1);
if (buttonState1 == 0 ) {
client.publish("spotify/rfid/but1", "0");
}
buttonState2 = digitalRead(buttonPin2);
//Serial.println(buttonState2);
if (buttonState2 == 0 ) {
client.publish("spotify/rfid/but2", "0");
}
int reading = analogRead(0);
//Serial.println(reading);
if (reading > 500 ) {
client.publish("spotify/rfid/arm", "0");
}
client.loop();
if (!mfrc522.PICC_IsNewCardPresent()) {
return;
}
if (!mfrc522.PICC_ReadCardSerial()) {
return;
}
if (Rflag) {
for (int i=0; i < 4; i++) {
//data is writen in blocks of 4 bytes (4 bytes per page)
status = (MFRC522::StatusCode) mfrc522.MIFARE_Ultralight_Write(pageAddr+i, &buffer2[i*4], 4);
if (status != MFRC522::STATUS_OK) {
return;
}
}
Rflag=false;
}
cardId = getCardId();
char buffer3[10];
sprintf(buffer3, "%lu", cardId);
client.publish("spotify/rfid/id", buffer3);
status = (MFRC522::StatusCode) mfrc522.MIFARE_Read(pageAddr, buffer, &size);
if (status != MFRC522::STATUS_OK) {
Serial.println(F("MIFARE_Read() failed: (R)"));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
Serial.println(F("Read data: "));
for (byte i = 0; i < 5; i++) {
Serial.write(buffer[i]);
buffer2[i]=buffer[i];
}
client.publish("spotify/rfid/idlms", buffer,5);
delay(1000);
mfrc522.PICC_HaltA();
}
unsigned long getCardId() {
byte readCard[4];
for (int i = 0; i < 4; i++) {
readCard[i] = mfrc522.uid.uidByte[i];
}
return (unsigned long)readCard[0] << 24
| (unsigned long)readCard[1] << 16
| (unsigned long)readCard[2] << 8
| (unsigned long)readCard[3];
}

Got my new PCBs in.
My Bus Manipulator, Backplane for 6502, and C64 PLA replacement.
I’m selling the leftover PCBs if you are interested.
These are not the final versions.
They should work, but they lack holes for stand-offs or feet.
Example setups for the backplane.
Using a flatcable or direct connection to my 6502 SBC.


The backplane was designed to be chained together.
(Horizontal female – male connection)
The vertical cards I’ve planned to make are:
PROCESSOR FUNCTION CODES (FC0, FC1, FC2)
These function code outputs indicate the mode (user or supervisor) and the address space type currently being accessed.

The following table shows the
meaning of these three bits.
FC2 FC1 FC0 Meaning
0 0 0 Not used
0 0 1 User data
0 1 0 User program
0 1 1 Not used
1 0 0 Not used
1 0 1 Supervisor data
1 1 0 Supervisor program
1 1 1 Interrupt Acknowledge
These outputs can therefore inform external circuitry what is happening
inside the 68000. They could, for example, be used to switch in differentbanks of memory.
Using a small 8266 with a display, I wanted to see if it’s useful to monitor this information.
So using a trick with the uln2804/uln2803 as level convertor (don’t connect the VCC, and the output will drop to a level that is around the 3.3v.
(I was out of bi-directional level convertors)
Latch demo
I’ve been using latches in the past, but I wanted to show how it works using a little demo setup.
Below movie is for the Bus Controller I posted recently.
While busy fixing my business site, and working for a customer, I build a testing rig for the 68000.
I first made a power-on reset schematic.
The timing is different from the 6502 power-on reset, and the 68k needs HALT and RESET being pulled low.




All Data lines are pulled low, emulating opcode 00 00
https://68k.hax.com/ORI%20to%20CCR
This will do nothing weird, and will increment the address and try to read the next opcode.
Resulting in an endless incrementing address bus, I’ve put a Led (Red)on Address A17.
Yellow is /RESET signal and Blue /HALT
I think we’ve seen Maderia .. 🙂
I bought a little notebook while being there.
I wrote about 12 pages of ideas, schematics and projects to start.

8085 Cartridge revisited
Problem with cartridge: prg is 17k, exomized 10k.
So you need 2 banks of 8k.
This disables basic rom, needed for the program.
The program needs to be relocated to 0x800 anyway.
So my exomizer options will take care of that.
But the basic is not being enabled again.
exomizer sfx sys -o data.exo -Di_ram_enter=\$37 -Di_ram_during=\$34 -f'LDA #$37 STA $01' 8085.prg xa frame.asm -o frame.bin x64 -cart16 frame.bin
Result … JAM