Alien Probes

Description

This board series include a STM32F405 microcontroler connected to a computer via a CH340G serial to USB chip. The probe is connected in place of the target CPU with a special connector.
The project is flagged as completed, as the hardware is now working. However, support for other CPUs may be added in the future, and firmware is still work in progress.

Details

The MCU that I use for this series of boards is a STM32F405VGT6. It has ample room for controlling bits, and it can also run a software emulator for most of the 8-bit CPUs out there. The STM can support DMA and interrupts.

Supported CPUs so far:

Z80, Z8001, 8088, PC-XT, Generic, 6502, 6510, 6809

All these provide test features:

1) Bit control and probe to test for short, continuity, and other basic malfunction

2) Bus transaction to test peripheral (helps tame periferals to peripherals!)

3) Memory editing, IO manipulations

4) (Z80 for now) Emulation, stepping and register manipulation

Files

IMG_20260817_050123101.jpg

Assembled Alien Probes: 6502, 6510, 6809

JPEG Image - 997.38 kB - 08/17/2026 at 09:03

Preview

6809.png

New Alien Probe for 6809

Portable Network Graphics (PNG) - 119.68 kB - 07/23/2026 at 17:56

Preview

6510.png

New Alien Probe for 6510

Portable Network Graphics (PNG) - 122.45 kB - 07/23/2026 at 17:55

Preview

6502.png

New Alien Probe for 6502

Portable Network Graphics (PNG) - 114.07 kB - 07/23/2026 at 17:54

Preview

6510-kicad.tar.bz2

6510 Alien Probe

x-bzip2 - 643.46 kB - 07/16/2026 at 05:16

Download

Project Logs

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New Alien Probes work!
Jacques Pelletier • 08/18/2026 at 08:43 • 0 comments

I just completed the hardware and firmware for the 6502, 6510 and 6809 Alien Probes. I pushed the firmwares on GitHub.
3 New Alien Probes: 6502, 6510, 6809
Jacques Pelletier • 07/16/2026 at 05:21 • 0 comments

3 New Alien Probes: 6502, 6510, 6809.
Np PCB produced yet but should be bug free. These are variants based on the Z80 Alien Probe. All Alien Probes could run an emulator. The firmwares for these 3 are not written yet. they should be available soon.
Very basic user interface
Jacques Pelletier • 05/23/2026 at 03:49 • 0 comments

The User Interface is done through a terminal (ANSI) with ANSI escape sequences. For now, the interface is rather basic but functional.
I had the opportunity to use them for debugging and it's rather cumbersome to use. Some could say cucumbersome!
Since I had these board working, I may make improvements to the UI for better use. I will put the code on Github.
Hardware release soon
Jacques Pelletier • 05/12/2026 at 14:08 • 0 comments

I will release the KiCAD files for the Alien Probes soon. There were small modifications needed for all of them, but they all work fine.
Z8001 Alien Probe revisited
Jacques Pelletier • 05/12/2026 at 14:04 • 0 comments

I reviewed the firmware to make a Pin Test menu all in one page. We can toggle each pin of the CPU directly.
8088 and Z8001 done!
Jacques Pelletier • 01/04/2026 at 11:06 • 0 comments

A basic testing software for now. It can toggle address, data and control lines. I need to implement the bus transactions.
Generic and PC-XT work!
Jacques Pelletier • 12/09/2025 at 05:36 • 0 comments

Just completed the firmware for these 2.
Z80-ICE2 works
Jacques Pelletier • 12/08/2025 at 06:25 • 0 comments

Z80-ICE2 works! Still there is a small glitch to fix when it does a memory write cycle.
Boards assembled
Jacques Pelletier • 12/07/2025 at 05:25 • 0 comments

All the PCB are assembled except for the crystal which needs a patch. Files are not released yet, I'll wait until the PCB are working.
One exception is the Generic Alien probe which had some Vdd pins unconnected. That's part of the game. So this PCB will need to be redone.
PCBs arrived!
Jacques Pelletier • 12/01/2025 at 21:45 • 0 comments

PCBs just came in!

View all 11 project logs

Discussions

Jacques Pelletier wrote 09/09/2026 at 10:15

Yes, I have 3 STM32 chips available and a 4th chip for the generic. Which ones do you need?

The 6809, 6502 and 6510 versions don't need patch, but the Z80, 8088, Z8001, PC XT and Generic need patches until I order new corrected version.

Are you sure? yes | no

mustower wrote 09/09/2026 at 08:24

Is it possible to buy a board equipped with the STM SMD for i.e. Z80 or generic ? I am not used to handle SMDs on PCBs, but I really interested in this project.

Are you sure? yes | no

Jacques Pelletier wrote 10/20/2026 at 23:55

It's possible, but since a few months, Canada Post doesn't allow to send packages to Germany and other EU countries. FedEx, UPS and others charge about 100 $CA for shipping. It would be cheaper to order the PCB from your favorite fab.
To solder a chip, you can use a solder paste and heat the PCB in a dedicated small oven (no more cooking in it). You place the PCB in the oven, and a small length of solder as an indicator over an empty space on the PCB. Put the oven to the max, wait for the indicator to melt and wait 30 seconds. Open the door and let cool.

Are you sure? yes | no

Alien Probes

Description

Details