Using the 32-bit v5.2.1 ASCOM ServoCAT driver with 64-bit Applications
Your best bet is to use the ASCOM Device Hub to serve as an intermediate bridge
between any 64-bit software and a legacy 32-bit ASCOM driver. An extra benefit
of using a software hub is that multiple applications can connect to your
ServoCAT at the same time.
A bit of background: the driver was last updated in June of 2015, and the driver is not currently widely used, especially with people moving toward Sky Safari and other solutions like INDI to control their ServoCATs.
The driver is written in Visual Basic 6 (VB6). VB6 is a unsupported legacy compiler and programing language. Creating a 64-bit version would require a complete rewrite from scratch in a different programing language. A rewrite would take weeks of undivided attention. A completely new driver would also require extensive testing time on the ServoCAT hardware. This is not something I would consider at this time.
As long as an intermediate software bridge works (like the ASCOM Device Hub), there is really no viable return on the time investment needed to build a 64-bit version. This driver is an uncompensated volunteer project, and much of my astronomy related volunteer time is now devoted to RMS/GMN meteor cameras. For details on this project, please see the RMS/GMN Global Meteor Network.
Peter Eschman, August, 2021