The A3640-remake v3.3 is an evolved Commodore A3640, incorporating the John Hertell A3640 cloned PCB.
PCBs exist as available open source for PCB fabrication. John Hertel desires that anything custom derrived from it also be open-sourced.
The board, fully populated with new and/or donor parts, supports a full 68040 CPU. The use of EC/LC 68040 parts is not recommended from an Amiga OS perspective. Most available and compatible 68040.libraries (C=, P5, MuLibs) expect the MMU and FPU to be present in order to control the 68040's behavior and/or to provide proper interfacing to software that, if compiled/optimized for the newer 680x0 CPU, generally expects a 68040 FPU to be present. A CPU library is required for stable behavior of the system when enabling the CPU Data Cache in any mode.
The boards are a functional equivalent to the A3640 Rev 3.2 which included all C= fixes at that time (including the jumper/gate addition). The SpeedGeek 2x wait state removal optimization GALs function on this board. The motherboard must be set for EXT/EXT clocking, and this board's clock (50MHz/2=25MHz) drives the motherboard, and the motherboard must be set for running that speed (A3000). For this reason, overclocking is not normally advised.
Some early test and special color/embedded message PCBs for several early contributors and testers were made by John Hertel, but are otherwise functionally equal to the available open source versions. Several board runs were made and built by other popular Amiga contributors.
The 68040 CPU needs OS 2.04 in ROM in an A3000, and OS 3.1 or later OS ROM revision in an A4000.
A 68040 CPU will produce enough heat that a heat sink is recommended. The board will work in an A3000D, but the case has airflow limitations through the installation area. Additional care should be taken to dissapate excess heat in that application. Be alert that a tall heatsink will impact the drive tray above.