I wrote a PCB design program in Assembler in around 1990.
It was 330,000 lines.
The page size then was 64K so I had to mess around with segment registers to access other memory.
The max I had to work with was around 512K.
There were no graphics libraries I could find so I had to write software to draw straight into the video memory.
Great fun.

 

Great fun.

Yeah. It's all too easy today, isn't it?

 

Yeah. It's all too easy today, isn't it?

I'm afraid it's much harder today to get direct access to video memory.

 

I'm afraid it's much harder today to get direct access to video memory.

Yes, if you rely on an OS to provide both access and security. Nothing stops you from writing for bare metal, if you are that kind of masochist.