How can I learn to build my own computer with Arm processors?

I know it used to be possible with Arm Classic cores; ie up to Arm11. Some of the CPUs were "simplistic"; as in they contained only the Arm core and very little memory, anything required for a bootloader, but more memory required external DDR. With newer technology, Arm SoCs became widespread, and to be honest, I don't know of many chips that don't include most of the controllers. Granted, some chips will require external DDR and NAND, but not much else. If you are thinking of the Good Old Days (c) where you needed a CPU, memory, memory controller, interrupt controller, serial controller and indeed *.* controller, I don't know of anything. Besides, most chips will use SMT, making it hard for enthusiasts. With the exception of Cortex-M chips, I've never heard of a DIP chip. You might want to try with an Arm926EJ-S or Arm1176, but in a way, it is a shame not to make the most of recent developments; the Cortex range really is worth it.

My question is about build a computer without SoC ICs and FPGAs. Is it possible? how?