Description

This is the Dual Clock Module which is supplied with the RC2014 Pro, RC2014 Zed or RC2014 Zed Pro, although it can also be used as a replacement for the clock module supplied with the RC2014 Classic II, or if you are building your own custom RC2014 variant. It can be used with Standard Bus backplanes (Backplane 5 or Backplane 8), or with Enhanced Bus backplanes (Backplane Pro). If the Standard Bus option is chosen, then a 10 pin straight header is also supplied. This gives you access to the /CLK2 signals.

Clock Circuit

This is a multipurpose clock module. Primarily it generates a 7.3728Mhz clock signal to run the RC2014. This is available on pin 21 of the Standard Bus which is used to run the CPU and UART. Optionally, this signal can be duplicated on the Clock2 pin of the Enhanced Bus, which can be used to clock a second UART port.

As a multi speed clock there are several options for clock speed output. The 7.3728Mhz clock can be divided by 2, 3, 4, 6, 8, 12 or 24, which will give outputs of 3.6864, 2.4576, 1.8432, 1.2288, 0.9216, 0.6144 or 0.3072Mhz respectively. Due to the serial baud rate being derived from the clock speed, this will equate to a baud rate of 57600, 38400, 28800, 19200, 14400, 9600 or 4800. Any of these speeds can be available on the primary Clock pin or the Clock2 pin.

In addition, there is a slow clock signal, of around 3Hz which, can be on the either the primary Clock pin or Clock2 or both.

The last clock option is for a SPDT switch (not supplied) to be used to manually clock the RC2014.

Reset Circuit

When power is applied the reset circuit uses a DS1233-5+ Reset Monitor IC will hold the Z80 in reset until the power levels have stabalised. A reset button on the module can initiate a manual reset too.

What do I get?

Dual Clock Module Single Speed PCB, single row header IC & socket, crystal, caps, resistors and reset button. Everything you need for a 7.3728Mhz clock module
Dual Clock Module Multi Speed PCB, single or double row header, 5 ICs & sockets, crystal, caps, resistors, reset button, header pins and jumpers. Everything you need for multi speed output clock module

For PCB Only option, see Core Module PCB listing

Documentation

Bill of materials