In this video I run some basic unscientific speed tests on the Ultimate64 using DolphinDos and JiffyDos.
Highlander71 Video on the subject
https://www.youtube.com/watch?v=-Xj7Jf5R5us
Resource for DolphinDos
https://rr.pokefinder.org/wiki/Dolphin_DOS
JiffyDos ROM store links:
https://store.go4retro.com/jiffydos-64-kernal-rom-overlay-image/
https://store.go4retro.com/jiffydos-1541-dos-rom-overlay-image/
JiffyDos Manual
http://www.jbrain.com/pub/cbm/manuals/JiffyDOS/JiffyDOS_V6_User_Manual.pdf
JiffyDos Patch utility:
http://dtvforge.i24.cc/sjiffy/
http://www.zahnarzt-adler.de/nlq/ajnsjd41.htm
