basically everything in this section of the regular area was built by me from the ground up. Blackbelt did some demonstration w/ bottom output ROM in the SE corner.
Square Rooter - (central westish side of the square plot) 8 bit input, 4 bit output + 5 bit remainder displayed at the control panel.
Multi-function ALU (northeast corner)- capable of OR/NOR, AND/NAND, XOR/XNOR, ADD, SUB, Return A/Return B, Increment A/Increment B
From north to south on the east end of the plot after the ALU..:
Basic 7 segment decoder
BUD RAM (with some modifications made by blackbelt to increase efficiency)
Switch programmable, 4 tick ROM (8 signal output, each side tileable)
square root extractor uses conditional subtraction to find the nearest whole square which will fit within the input value and also outputs the remainder. utilizes a generic adder to perform since it was easier to work with / debug.
ALU utilizes a 2 wide adder tiled 4 times. basic logic functions and add/sub use !a, !b, OR, Cin, Cflood in standard combinations to generate. Return A/B uses a 'force' function to force all A or B inputs to logic 1, and !a to force them to logic 0. thereby allowing the other input to pass through the ALU. Increment A/B forces a/b input to logic 1 and inverts, but then also adds Cin to increment. I've currently got 2 versions of this in the area, and I'm working to add features to it.
7 segment decoder uses a stacked decoder that's just a bit cleaner than my previous attempts at it. current decoder Handles inputs from 0-9 but is expandable.
BUD RAM is a pretty standard design for BUD RAM. nothing special
switch programmable ROM uses a central input (which would come from a decoder) and spreads outward. when a row of ROM is selected a torch forcing the output lines off is turned off, thereby enabling the switch position to determine the state of the output torch. useful for main program ROM applications where a non-destructive method of reprogramming would be useful.
Comments
I've added dual read RAM to
I've added dual read RAM to my arsenal of stuff over this area. Also am adding a computer to the area. not sure what the program will do just yet, but I'm adding it all the same.
computer
The 8bit computer is finished now. The program multiplies 2 4bit numbers and displays the result on 7 segments. Copied a DD and 7 segment for the bcd conversion and display out of convenience, since the goal was to get the multiplication algorithm done right.