Off topic digital help needed

[Matthew Porth]

     Hello again,
     
        Yes, it's my third posting and I need information (I am still 
     learning!). What I am after is information on digital delays. 
     Basically how to build one.
     
        I thought of using just a counter, a timer, some static ram and a 
     DAC/ADC chip which would work but not for my purposes because I 
     need(want) the delay to sync to midi signals (or a multiple of the 
     current tempo anyway).
     
        Can someone point me in the right direction. I guess I will need to 
     use some CPU and a UART. But can anyone tell me where to find info on 
     building CPU based digital circuits.
     
        TIA,
     
        Matthew.