Clock update and Hodge podge

Day 27

     In case you have not looked over the contents of the Google drive folder I posted here is the clock circuit diagram. Looking it over in this form as opposed to in any of the HP drawings seems a bit more sensible to me. Most likely due to my having drawn it out. Operation of the single step is becoming more clear now and the overall function is starting to take shape in my head. This bodes well for when the circuit is built as it will likely reveal what is left for me to find in it.


      Looking over the HP computer papers 1 theme is always present, control is up to you to figure out and while I intend to do just that the RC2 design shows many of these control mechanisms plainly. In the full adder of the ALU's the logical function of the increment function is described but not shown the RC2 goes into full detail as to how this is accomplished. As an amendment to my post from 27 Feb the logic block of the RC2 is much less robust that the HP computer as it can only AND, and NOT while the HP computer adds OR and XOR this is a severe speed limitation as OR and XOR are important functions however it only pays a speed penalty as with the AND and NOT you essentially have a NAND gate and NAND can be chained to create any of the other functions, so the ONLY penalty is speed. Speed is a penalty that can be paid easily with the RC2 as so many of it's other features add so much more speed to the system this also has the added benefit of reducing the number of enable circuits in the computer which while not much of a reduction in parts is still something to consider. More differential notes on the RC2 show that a single relay clock circuit was used instead of the larger but more stable HP clock. The finite state machine in each appears to be capable of 24 steps though the reset circuitry is different and the RC2 uses a 12 count with a prime count for each step more will come on that soon though as I believe the finite state machine will be the next prototype I build after the clock and at least 1 bit of the ALU, time will tell.

     One thing I am starting to see is that while these 2 computers are drastically different, these differences mask the overwhelming number of similarities. Both authors are extremely competent and very efficient and I think that explains why even the differences are similar in many ways, I intend to leverage this as the HP papers show little of the control circuitry but the RC2 shows much of it but glosses over the more in depth explanations of the functional bits. Combining these 2 works and modifying things here and there will allow for potentially the efficient and true design I desire.

A further note on parts this week I ordered my second shipment of relays as well as the capacitors for the clock, 50 switches, and 20 indicator LED's this puts me in a good place for prototyping once they all arrive within a few weeks. These orders with the first batch which I'm still anxiously awaiting will allow for up to the full ALU and clock to be built and possibly the finite state machine.