I've been reading up on some old tech manuals and found that apparently some IC chips where designed and tested in BASIC. While I already have a copy of Eagle and fritzing these are more for board designs and not IC development. So as the title asks, what would the best way to go about designing and testing hardware before even laying down any solder?
If you are asking this question, I think designing ICs may be jumping a bit too far into the deep end as the first step.
For virtually testing circuits, consider simulation software such as a VHDL/Verilog simulator (for logic) or Spice (for analog).
When you say "tested in BASIC", I would interpret that as "simulated using a simulator written in BASIC".