This module has been retired, however, you can buy the bare PCBs direct from Feilipu store here https://www.tindie.com/products/feilipu/am9511a-apu-module-pcb/

The Am9511A APU module is designed to work with the RC2014 Standard Bus and optionally with the RC2014 Extended Bus. Supporting logic is provided to ensure that the Am9511A APU is adapted to the RC2014 system clock, and to the Z80 control signals.

The Am9511A requires both +5V and +12V power supplies. To obtain +12V a switch-mode boost converter is provided. Consumption of between 50mA and 100mA from both +5V and +12 V supplies is typical, and the device packaging (24-pin ceramic DIL) is designed to dissipate up to 2W. It is normal for the Am9511A to operate HOT TO TOUCH and the APU Module is constructed with 4-layers and complete Vcc and GND layers to enable rapid heat sinking into the PCB. Please ensure that this module is either fitted at the very end of the backplane, or at least 1 slot away from the next module, to aid in ariflow,

The Am9511A-1DC device operates at a maximum of 3MHz. Therefore to operate successfully with the RC2014 7.3728MHz system clock a 3:1 reduction of the clocking for the APU is required. A 50% duty 1/3 rate circuit has been constructed from two D flip-flops and a JK flip-flop, and several NOR gates.

The kit is primarily designed to be used with the z88dk development environment, and has a floating point library available. However, a modified version of Microsoft BASIC is also available which will offload mathematical functions for a slight speed increase, and also provide a built in hex upload routine for quick and easy Z80 hex file uploads. Note that this new BASIC only supports the 68B50 UART, so will only work on the, RC2014 Mini, RC2014 Classic and RC2014 Classic ][

Two variations of this kit are offered; Standard Bus (single row header) and Enhanced Bus (double row header). The Enhanced Bus option takes advantage of the /WAIT signal in the additional header pins. The Standard Bus option will require the user to either run a jumper cable between this module and the CPU, or to make a modification to the board with the CPU on it to bring the /WAIT signal out to the USER1 pin.

This kit uses a 12v boost regulator for the AM9511A. Note that one of two different variations may be supplied; a 3 pin version which sits flush against the PCB with the components facing outwards, or a 4 pin version which is spaced away from the PCB on header pins with the components facing the PCB. The 4 pin variant needs the SHDN pin left floating as shown in the photographs.

See the documentation link below for full usage and assembly instructions

Important note The AM9511A went out of production many many years ago, therefore almost all chips on the market are reclaimed units. If you order this as a complete kit, the AM9511 will be tested before being sent out - however, in the interests of transparency, you can probably save money by ordering the PCB and sourcing the component yourself.

RC2014 is a trademark of RFC2795 Ltd.