Photoshop bitmap mode ? You can find it either via the properties for the document or via the image menu and Bitmap command
Firstly, go to the image menu and gray scale and then go from gray scale to the required color setting
You will now see another panel which gives a number of options and that means there are a lot of creative options such as halftone screen which also has it's own options. You can also create interesting designs by using different output values such as 300, 72, 1 etc
You can set the frequency, low or high as well as angle and also the shape (ellipse, line etc). Shape such as line. Or using the shape of round. Or change the frequency as well as the method
As you have 100s of patterns in your patterns panel, you can also use the custom pattern option and select a pattern to use. You have no control over the scale or rotation. The end result can be quite interesting and not always what you expect but the patterns means you can create all kinds of wonderful designs. I would suggest perhaps modifying the image using levels or exposure before you go to the mode as I always find without lightening the image, the image is always often too dark for my taste You can use type etc as a pattern design as well. There is also an option for a pattern dither but that appears to offer no variation
A few of the conversions are fairly limited such as 50% threshold method. However, 50% threshold is nice for a cartoon like effect. Of course, you can always combine the design with a saved copy of the image once you return to RGB etc
Only invert is available for the adjustments which is not surprising as the image is black and white.
You can add type. Brush strokes work as well though the blending mode range is limited. Custom shapes can be used. Define pattern and brushes are available and that is useful. No filter are available
Goto the Photoshop image menu and gray scale and then repeat but go to RGB Once you are back into RGB mode then you can add effects such as oil paint, blurs etc to the image. Or use line halftone and then use a blending between layers to re-color