Re: Z80 Designs

>..... I have recently began building and designing a Z80 based system
>....[snip]....
>I am debating what construction method to use. Steve recommends point to 
>point soldering in his book, but some references I have read seem to 
>indicate that a pcb would greatly reduce interference problems....

Using "breadboard" type PC boards (mine had 3 or 4 holes per IC pin),
I've wired point-to-point/daisy-chained boards with over 200 14/16-pin
CTuL and over 100 TTuL IC's running as high as 10 MHz and have never
had any problems.

Some helpful techniques:

  * Use TEFLON-INSULATED WIRE, so "jamming" a solder pencil-point
    into a bunch of already-soldered wires doesn't melt anything!

  * Use a 0.01 mf capacitor across EVERY IC's power pins and scatter
    50 mf caps across the power bus(es) at multiple convenient spots.

  * Test EVERY wire or daisy-chain from each "source" IC pin to every
    "destination" IC pin to which that wire or daisy-chain goes (that's
    FOUR solder joints for just ONE wire!) with an audible "beeper"
    (that's better than a visual indicator because you can keep your
    eyes on the probes!) that can report a resistance (read "cold solder
    joint") less than a tenth of an ohm.  (My beeper is home-made and is
    a lifesaver!)

--Myron
-- 
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PhD EE (retired).   "Barbershop" tenor.   CDL(PTX).   W0PBV.   (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)