Front of Protar A500HD
Rear of Protar A500HD
A SCSI Controller which connects to the side expansion slot of the A500. As well as an internal 50pin connector, it has also an external DB25 SCSI connector, Game switch (for disabling the autoconfig of the scsi controller) and supports an external power supply. Unusually for most A500 expansions, it supports additional memory in the form of 1 x 72pin SIMM slot for up to 8MB of additional RAM. If an additional power supply is used with the Protar then the A500 no longer needs a separate supply, it can also be powered from the Protar.