The control ports that mice plugged into were not identical between the Amiga and C64/C128 line, so necessarily their mice would not be compatible with each other. However, since both the Commodore 128 and the Amiga (1000) had identical case colors, it was reasonable to produce mice that matched each other in color at least. What was NOT reasonable, however, was to produce mice that were completely IDENTICAL from the outside, while remaining incompatible with each other.
Oh, and also, there weren't just two of them, but three functionally different mice in the exact same case:
Let me introduce you to the Commodore 1350, Commodore 1351, and the Commodore 1352, also known as the Amiga "Tank" Mouse.
Released around Sep of 1985, the 1350 is the most odd of the three mice, as it's really a directional (non-proportional) Joystick stuck in a mouse case. It works with both the C64/C128 and the Amiga, but only as a joystick, and not as a very good one, since a mouse is a terrible way to persist directional movement.
In March/April of 1987, the 1351 mouse was released. This is a true proportional mouse for the Commodore 64 and 128, and it works very well for that purpose. GEOS was greatly enhanced by this product, and its design earned Commodore some sort of patent! The 1351 is also special in the fact that it can emulate the 1350 as a joystick by holding down the right button on boot.
In November of 1985, the Amiga became available for purchase, and that's when we first saw the Amiga "Tank" mouse in its original form. It wasn't until 1988, however, that it was marketed to Commodore PC users as the 1352. Like the 1351, it is a good and proper proportional mouse for Amigas and Commodore brand PCs. It is not compatible with PC "serial" mice, however.
The big question:
If you get handed one of these things, how do you tell them apart?
Well, let's start with the easiest thing to check: as you can tell by the picture above, they are absolutely identical from the top, so that's not the answer.
What about the cable ends? Since all three have different pinouts, perhaps the connector is different:
Here you can see two kinds of connectors pictured: A pair of fat-but-shorter connectors on the right, and a longer-thinner connector on the left. All three of those are from Commodore 1351 mice. So-- not entirely helpful. Amiga mice tended to have the long-thin connectors, and the 1350 tended to have the short-fat connector, but as you can see, the 1351 could have either.
While the above is disappointing, there is ONE connector that is a dead giveaway:
The original Amiga 1000 mouse had a large angled connector designed to fit snugly into the side connector of the Amiga case. When you see one of these connectors, you can be sure you are looking at an Amiga mouse.
OK, so what about the bottom labels? Surely Commodore put the model information on the bottom! Heck, we should have looked there first, so let's take a look:
Except for the odd 1351, and the giant AMIGA letters on a few A1000 mice (not pictured), there is no model information. Believe it or not, however, there are at least some patterns. You see, the top row are all 1350s, the middle are 1351s, and the bottom are Amiga mice.
Amiga mice seem to usually have similar looking bottom labels, even if there isn't any model information. They have those dark bold black letterings, the C= commodore lowercase logo, and a serial number beginning either with an A or B. However, there are exceptions to this as well. Pictured above is an Amiga 1000 mouse, with a lighter colored labeled and serial beginning with TM. Such labels have also been seen on non A-1000 mice.
The 1351s, when you are lucky, actually say 1351 on them. When you aren't lucky, you get the lighter colored C= Commodore logo and lettering with a simple numeric serial number. But mine is a small sample size, so who knows what variations are out there.
The 1350s are the only ones that say Commodore Business Machines on the bottom, again with lighter colored lettering than the Amigas, and a serial number beginning with X. Although, again, that's just my small sample size.
But...
... maybe you aren't comfortable with this method. After all, there's no way I can survey every single Commodore mouse. Suppose I made a mistake above, and some 1351s have labels that look like the Amiga, or some Amiga mice have labels like the 1350 or 1351s? Surely we can just pop the top off and look inside to tell the difference:
Now we are getting somewhere. This picture is the 1350, and it has a separate button board above the main board. So, that's how we can tell those from the 1351 and Amiga mice below, right? Wrong. The raise "button board" seems to be more a sign of when the mouse was made than the model. Since the 1350 and the Amiga mice were made earlier than the 1351, the early revisions will often have this raised button board. Meanwhile, later versions of the 1351 and the Amiga mouse will all be single-boards, as shown below. As far as I know, the limited run 1350s do all have that raised board, but I could be surprised.
The later boards on the 1351 and Amiga mouse respectively, pictured above, have their components consolidated to a single board. The later 1351s don't seem to have any resisters along the left-hand-side of the board, while the later Amiga mice always do -- either three or five, depending on revision.
The biggest difference, however, and the one certain SURE-FIRE way to tell the difference between these three mice is the chip inside.
So that's the answer!
Except that it's a little complicated.
The Commodore 1351 mouse is easy. It almost always has a C= CSG 5717 chip in it. In fact, that same chip also appears in several 1351 clones I ran across, such as the CMD SmartMouse. So, if you see the CSG 5717 inside, you know you are looking at a 1351, period. Although, I found a 1351 online with a chip labeled "390209-01" -- so I guess that one too?
The Commodore 1350 has a chip which is probably a little "CMOS 4 bit microprocessor with A/D converter". This would make sense, since the analog signal from the wheel sensors are converted into simple on-off signals for the various directions. In this case, I'm seeing the Mitsumi MP01 and the MB88201
Lastly, the Amiga mice have an analog quad comparator of one sort or another. I think the 339 at the end is probably the giveaway here.
So!
That's the best I could come up with. Clues in the labels and the connector, and then a final answer in the chip, if you are able to find the model number online to figure out what kind of chip it is. If you have a Commodore or Amiga mouse with a serial label different from the ones discussed above, please drop me a line.There might also be a way to check for the right-mouse-button on pin 9 of the Amiga mouse, but I was aiming for more visual inspection methods, so I didn't investigate this. Still, if you want to pursue that, here is a pinout comparison. The 1350 is labeled here as "1351 Joystick Mode".
Clearly Commodore should have thought about the confusion that might erupt around three products that look so similar, but which are functionally so different. Hopefully this post can help anyone faced with the frustrating situation I found myself in today trying to distinguish between a pile of tank mice from someone else's collection.