Lo-fi drums generally come in 2 ways.

1: using an old sampler, or running your own samples through an sampler and or using samples that were run through an old sampler, like from a sample pack, to use in your own modern sampler, software or hardware, which would allow you to modify them to your own liking.

or

2: using an old school/vintage rompler/drum machine that are essentially the same thing, unless they're analog, but limited to that machine, unless of course you use a 1: sampler.


There other ways like running audio through cassette tape, VHS, old digital multi track recorder, ect

Here are some vintage machines
Paid: https://www.wavealchemy.co.uk/product/revolution/
Free: https://www.producerfeed.com/2022/11/dr-84-free-retro-drum-machine.html
Paid: https://www.uvi.net/en/vintage-samplers
Paid: https://www.alyjameslab.com/
Paid: https://www.native-instruments.com/en/products/komplete/expansions/faded-reels/

Korg has some, Roland has some

There are a lot of other choices but they're all essentially the same thing, samples or modeled. alyjameslab can actually open EPROMs from other drum machines of the time.

Best way imo, is getting a hardware 8/12 bit vintage sampler. There are newer samplers that do the "lo-fi" thing but I don't like them personally. YMMV