If you’ve been geeking out for a couple decades, chances are you at least saw the Radio Shack ProbeScope at some point in time.

The Radio Shack ProbeScope
The Radio Shack ProbeScope

I bought one back in the late ’90s and found it to be fairly handy for a number of things. Its sampling rate, as I recall, was 4MHz, meaning you could use it to at least detect the presence of RF in a circuit. I also used it to help me debug the code I wrote to emulate serial communications in the microcontroller for my Digital Setting Circles project.

The ProbeScope included a floppy disk with software on it for both DOS and Windows that allowed you to view the waveforms on your PC by connecting the ProbeScope to the PC’s serial port. Alas, the software was written back in the 16-bit days and won’t run on the 64-bit operating systems on most modern PCs. Plus, who has a floppy drive to read that disk anymore? But if you’ve read any of my other blog posts, you know I have a habit of finding ways to revive old but still useful technology that’s long since been left behind.

It doesn’t help matters that Radio Shack has essentially gone belly up. My efforts to find the software for download on their support site were fruitless–I couldn’t even launch the site! But all hope is not lost. It’s the Internet Wayback Machine to the rescue! The Internet Wayback Machine is an archive of snapshots of countless websites, allowing you to travel back in time to see those websites as they existed at various times in the past. How cool is that? So even if I can’t find what I need on the current Radio Shack site, I can go back 15 years or so and maybe find it there. With the Wayback Machine’s help, I was able to find a link to Scope41.exe, the setup program for the ProbeScope software. I also was able to find a PDF of the manual.

So, I’ve got the software now. What next? Well, I need someplace to run the software, and I also need a serial port to which I can connect the ProbeScope. The latter is fairly easy to deal with–it’s not hard to find a decent USB-to-serial converter cable these days, or you might even have an older PC with a real serial port. The more challenging part is finding an environment to actually run the software. For that you need to be running an older 32-bit version of Windows (Windows XP or earlier), or the old 16-bit Windows 3.1, or even (gasp) DOS. These things aren’t quite as hard as you might imagine, thanks to virtualization (software emulation of PC hardware). You can, for example, run VMWare Workstation Player (free for personal use) on your PC and then install Windows XP in a virtual machine, giving you a platform on which you can then install the ProbeScope software. Another approach is to use Dosbox, a DOS emulator, to run the Probescope DOS software directly, which I think is the easiest solution to implement.

It doesn’t take a whole lot to get Dosbox up and running–just download it and install it on your PC. When you start Dosbox, you’ll be in a command line environment with a Z:\ prompt facing you. You can use the mount command to tell Dosbox what folder on your hard disk you want it to use as the root C:\ folder within Dosbox. A convenient approach to this is to simply create a folder on your PC to be your dedicated Dosbox C:\ folder, and then tell Dosbox to mount that folder on startup. You can do this using the dosbox config file (accessible from your Start menu under Dosbox-0.74->Dosbox 0.74 Options. This will open a text file which Dosbox reads at startup to configure itself. In that file is a section (towards the bottom) that begins with “[autoexec]”. Add the following lines to that section:

# Lines in this section will be run at startup.
# You can put your MOUNT lines here.
mount C C:\DosBox

(substituting “C:\DosBox” with whatever folder you created). Then look for another section in the file starting with “[serial]”, and edit the line starting with “serial1=” to look like this (but change “COM6” to whatever com port is assigned to your PC’s serial port or USB-serial cable):

serial1=directserial realport:COM6

This tells DosBox that when a program running inside it tries to access COM1, connect it to physical COM port 6. Now save the config file.

Next, create a folder within your DosBox folder named “scope” and copy SCOPE41.EXE (the software for the ProbeScope you downloaded previously) into that folder.

Now start Dosbox. It should automatically start with the DosBox folder as your root folder. Type

c:\> cd scope

to switch to the scope folder, and then type

c:\scope> scope41

This executes SCOPE41.EXE, which is like a self-expanding zip file. It will create all the necessary files needed to run the ProbeScope DOS software. Once it finishes, set up your ProbeScope, plug it in to the PC, and power it up. Then, in DosBox, type the following command:

c:\scope> scopedos

This should start the ProbeScope software, and you should see a screen like this:

ScopeDOS in action

The signal you see is the 1-KHz square wave calibration signal provided by my brand-new Siglent SDS1102CML+ digital storage oscilloscope. :-) Here’s what it looks like on that scope:

The Siglent DSO’s display

13 thoughts on “Revisiting the Radio Shack ProbeScope

  1. Thanks for posting this. I just found my Probescope in with some old ICs and stuff that I got at another Radio Shack closing 20 years ago. I enjoyed using it back then, so thanks for figuring out how to get it to work.

  2. Please, if you have the scope41.exe program, can you send me , I try to get on WayBack Machine, but no way. I´m trying to do to function my probescope on pc , But no way to read the diskette. Thanks a lot.

  3. Hi Dave,
    It was nice to find your blog. Like MrGraphMaN, I, too, found an old ProbeScope in my rather large(7 storage buildings on my property) junkbox. Funny thing, I have no idea where it came from but, I have been finding a lot of stuff like that lately. I pulled out a 12V wall wart and checked out the probe. Lo and behold, it works!! Started looking for an archive of the software and wound up here. Fortunately for me, I still have an old Compaq laptop that still has DOS and Workgroups on it. The Compaq was from the days when I had a pager/cellular store. It was my portable programmer for pagers. Will let you know how that works out. After reading your background, I recognized a lot similarities. I am also a HAM(over 50 years now), musician( although it was my music teacher and not an uncle that spurred my interest in Ham radio), have a BSEE but no longer work in the field. I have also been around computers a good portion of my life, like you starting with a DG machine but got my first computer at home in 1978(Altair 8800) using an old model 28 teletype with a reperf machine attached. Later getting a Lear/Siegler terminal. Worked with a couple of CDC 1700s when I first started at Motorola and then moved on to Hp 9000 machines to automate my R.F. lab. Liked the 9000s even with the host language being HP Basic. Hp Basic was actually a pretty good language for lab automation and the IEEE 488 buss was nice and incredibly fast for the time and it allowed all the machines talk to each other. Will let you know more as time goes on. I am very pleased to run across your site. Hope to chat more as time goes on.
    Best Regards,
    James Munzer

  4. Radio Shack, 22-310, Software For Probescope, For Computer Interface, Includes DOS and
    Windows Software, Version 4.1

    Sitting Here On My Desk, Fresh Because I always made a copy and loaded from there.

    Tom Let me know if you want a copy!

  5. HI Dave,
    When I sent you the message about my Probe Scope, I was fully intending to check in here regularly. I had retired from my job so I could stay at home and take care of my wife who was terribly ill. As it turned out, I didn’t know how ill. She had been home bound for a number of years due to a combination of ailments but, I thought we had a chance to make her better. Sadly she had hidden the results from one of her doctors from me and as I found out later, she had cancer in an advanced state and she was terminal. I was still in the dark so, I was advocating for her and had hope that one of the local hospitals which is nationally know for their diagnostics and the team of doctors associated with the hospital is a Dream Team.Admittedly she had no real life left. She would sleep, wake .go to the bathroom and then I would fix her a small meal and she would go back to sleep. Her continual pain was relentless and she had pain meds that would knock out a horse, So on the 21st of February 2019 my wife took her own life.. This past week I started thinking about my Probe Scope and then I couldn’t remember your site. I was checking out my bookmarks the other day and found I had marked your site and when I saw the name, it all came back.SO I am hoping to get back here regularly. One note: I remembered you do a lot of portable operation with you HAM stuff, I found batteries on Ebay you might be interested in. They are 3.7 Volts at 10,000 mAH(10 AH) and they really seem to be just that and not expensive. I will send you the link. Good to see you are still around. Hope to chat more soon. 73 James N7XSN

  6. It’s really cool to see there’s still some interest in these scopes even in the current year. I’ve had mine for some years now; I bought it thinking it would be a decent route to learn oscilliscope basics with. Since all I’ve ever done with it is diagnose / fix audio equipment I’ve never upgraded.
    It’s been a long while but I finally got back into audio but after digging out my Probescope I had everything but the leads to it.. I wonder if anyone knows of any decent substitute leads for it? Or is it a lost cause..?

  7. Thanks for this! I just ran across my ProbeScope today (I had been meaning to get it up and running again). I had an old XP machine it would have run on, however that machine was slowly dying (WiFi stopped working and the plug-in card stopped working), so I didn’t have anything that would run it.

    Now that I’ve got the software, I just need the 9-pin serial to USB converter and I’m all set. Thanks!

  8. Purchased a RadioShack ProScope in 1995 in tech school. NEVER used it until a week ago teaching my kid how to back-probe a faulty crank-position sensor on a Buick to a successful repair.

    Later I located this Blurb/Blog giving me the idea to try the software in DOSBOX on both Windows 10 and old XP. The ‘Windows’ app itself failed to see my USB installed serial port in XP. Bummer…. Still looking to resolve that. Must be a common translation app, or the direct to hardware is clearly a no-go in XP? The DOSBOX App clearly works around that problem successfully in X P. MUST BE A WAY!

    Looking forward to more auto repair alone with the ProScope. Why?! Cause I can and shouldn’t with all the CHEAP alternatives from CHINA flooding the market. Seriously…. handheld color multichannel scopes for less than $100. Seems like cheating.



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