guides, slices, for tiling?

I'm trying to take a big image and break it up into a lot of tiles. I know I can create horizontal and vertical guides and then make slices from those guides and then save each slice as a separate image all at once, but the thing is - that would require me to make a LOT of guides. I have a 1600x1600 image and would need 31 guides across and 31 guides down. (which makes 32 images up and down dimensions-wise) I will be dealing with bigger images. I can't do this for each one.

Is there an easy way to do this? Is there an easy way to tell Photoshop "make a horizontal guide every 50 pixels up to down, and, make a vertical guide every 50 pixels left to right"? I know there are separate programs that will do this like Split and Tile, but I don't want to have to pay for one.

I know C++ and thought about reading the data from bmp files to make my own program to do this, but the pixel data inside BMP files seems to be organized in an odd way. Like, the hexadecimal values are backwards and I don't know what the gibberish in the beginning of the BMP file is for.

And now that I think of it, the most effective thing to do would be to have a "Slices from Grid" button like the "Slices from Guides" button. But I don't think they have it.

I know a plugin in Gimp that would be able to do this the simpler way, but I'm not sure about Photoshop. Sorry.