Apple have removed support for 32 bit applications from Mac OS 10.15 (Catalina) and later. VirtualAcorn products run in 32 bit mode and won't function natively on any version of Mac OS X that runs in 64 bit mode only. To see if development of a 64 bit version of VirtualRPC was viable we've been asking customers to tell us if they are interested, regretfully we haven't had enough expressions of interest to stand any chance at recovering the development costs. With Apple also switching to ARM based processors in new Mac OS X computers producing a 64bit product designed for Intel processors could never repay the development costs. As such we have had to shelve plans to produce a 64bit version of VirtualRPC for MacOS X.

Running a 32bit VirtualRPC on a 64bit Mac

This technical support article explains how you can still run VirtualRPC on a Mac running Mac OS X 10.15 (Catalina). You will need modest technical skills but the methods can be used with most 32 bit applications.

Suported Processors
Intel 32 bit or 64 bit processor (running in 32 bit mode) with a speed of 1Ghz or above (multi-core recommended), for example:

Intel: Core i7, Core i5, Core i3, Core2, Core2 Quad or Core Solo.

PowerPC: G4 at least 800Mhz, G5 at least 1Ghz (performance will be slower than an Intel processor with the same clock speed)

Required Operating System
VirtualAcorn products will run on any version of Mac OS X from 10.4.0 (Tiger) to 10.14 (Mohave). Currently VirtualRPC for Mac will not run natively on 10.15 (Catalina) or later but see the article link further up this page for several ways you can get around this problem.

VirtualAcorn products are not suitable for 'Classic' versions of Mac OS.

Required Memory
The absolute minimum memory requirement for G4 or G5 Macs is 512Mb of RAM. For early model Intel Macs we recommend at least 1GB of RAM. For late model Intel Macs we recommend at least 2GB of RAM.

Required Graphics Card
32Mb of graphics memory with OpenGL support. Any Intel powered Mac will meet this specifications.

Required input devices
Mouse and keyboard. Apple Mighty Mouse recommended.

Storage
Minimum 500Mb of free hard drive space and optical drive for the installation CD (The VirtualAcorn installer is designed to be portable and can be copied from the installation CD to a USB memory stick using any Windows, Linux or Mac OS X computer)