I read from your comments that you have the netlist hooked up to a driver already.
In this case, run
Than run "make" again to compile the updated file in src/lib/netlist/generated and to relink mame.
In the nltool log verify, that you find something along the lines
INFO: External static solver nl_gcr_f259d5f9a247b8f6_29_double_double found ...
This should give approximately 58% more performance
I can understand your frustration. Had it as well on certain circuits.
- Compare it to the performance of real SPICE implementations
- Bear in mind you have created a near-perfect documentation of the hardware
- Consider the future scalability.
The netlist format is kept as easy as possible - just a couple of standard elements, I even replicated the c++ preprocessor so that on separate processing of netlist files you don't even need e.g. nltool.
For the mame/discrete project I have created SPICE models e.g. for analog inputs / voltage sources. This means if you use kicad you can run very simple circuits through ngspice.
There is a ton of proof-of-concept in netlist. which needs attention, agreed.