RC2014 is a simple 8 bit Z80 based modular computer. It is inspired by the home built computers of the late 70s and computer revolution of the early 80s. It is not a clone of anything specific, but there are suggestions of the ZX81, UK101, S100, Superboard II and Apple I in here. It nominally has 8K ROM, 32K RAM, runs at 7.3728MHz and communicates over serial at 115,200 baud.
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 the same as the basic clock module which is used to run the CPU. Optionally, this signal can be duplicated on the Clock2 pin of the enhanced bus, which can be used to clock a UART.
As a multi speed clock there are several options for clock speed output. The 7.3728Mhz clock can be divided by 2, 3, 6, 8, 12 or 24, which will give outputs of 3.6864, 2.4576, 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, 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 600Khz which, again, can be on the either the primary Clock pin or Clock2 or both.
There is an input from an external clock too. This can be derived from a signal generator, or from a basic clock module piggybacked on this module. Again, this signal 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.
The reset circuit has been upgraded to allow for an automatic reset to be triggered shortly after power is applied to the RC2014. Either the active low reset or the active high reset signal can be connected to the Reset2 pin on the enhanced bus - although be aware that this pin is also used by the Pageable ROM and 64k RAM for the page signal, so you can only have one or the other.
Note due to a screwup on the first batch of boards, if you wish to use any of the generated frequencies other than 7.3728Mhz, you will need to solder a bridge between pin 2 on U3 and pin 13 on U4 as indicated on the last photo in the gallery above.
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Tinkering with old 8 bit home computers to see what can be done with modern solutions.