Masochist's Video Card

Current Part:

Wire-Wrap Tool
8x 74-244, Octal Buffer
7x 74-193, 4 Bit Counter
1x 74-138, 3-8 De-mux
6x 74-30, 8-Input NAND
1x 74-08, 2-Input AND
6x 74-04, Hex Inverter
1x 74-02, 2-Input Nor
1x 74-00, 2-Input NAND
555 Timer
10 MHz Oscillator
8x 20 Pin Sockets
9x 16 Pin Sockets
15x 14 Pin Sockets
3x 510Ω Resistors
3x 1kΩ Resistors
2x 2kΩ Resistors
100kΩ Variable Resistor
2x LM7805
30 Pin SIP Sockets
2x Green LEDs
3x 330Ω Resistors
Jumper Wire
9v Battery Clip
AA Battery Holder
Copper Clad PCB
Ferric Chloride
15 Pin Female D-Sub Connector

Parts List Details
           If you're not familiar with some of the parts listed above, don't fear! I have gone ahead and described the important parts from above in more detail below.

           This material is perfect for wire-wrapping because the board has drilled out holes every 2.54mm (0.1"), which is the exact pitch of all discrete logic IC pins.

Wire-Wrap and Wire-Wrap Tool
           To connect the circuit together, we will use a small 30 AWG wire called 'wire-wrap'. The name comes from the fact that the wire wraps around the socket pins to make point to point connections.

74-193 4 Bit Counters
           These 4-bit binary counters will be used to count up to specific values in order to output the Hsync and Vsync signals at the proper time. Also, when certain count values are reached, they should clear the count value to '0' in order to start over.

74-244 Octal Buffer
           The inputs to these devices will be hardwired to ground or power, depending on what the output state for the color signal should be (White/Red/Yellow..etc../Violet/Black). The 74LS138 de-mux will be in charge of enabling the buffers, along with two enable wires from the hsync circuit.

74-138 3-8 De-Mux
           This de-multiplexer will serve as the eight state machine controller for the color generator. An attached 74-193 clock will tell the 74-138 to cycle through each of the 8 states over and over until infinity.

74-30 8-Input NAND
           Since some of the count values we need to 'see' are very large, we need to use an 8-input NAND gate to check to see if specific count values have been reached.

74-04 Hex Inverter
           This device inverts an input signal to the opposite value. For example: if input is 1, the output is 0. This will be used to invert some signals so that they are the proper value when they reach the 74-30 8-Input NAND gate.

74-02 2-Input NOR
           The actual output Vsync and Hsync signals will be triggered to switch states between logic 0 and logic 1 by using a Set-Reset FlipFlop. This SR FlipFlip will be created using two NOR gates.

74-00 2-Input NAND
           Some of the count values will require more than 8-bits, so in addition to the 8-Input NAND gate, a few 2-Input NAND gates will be used to help capture some larger count values.

Jumper Wires & 7805
           Jumper wire (breadboard wire) is used to connect the masochist's video card to a VGA connector breakout board. The 7805 +5v regulators are used to keep the output voltage to the entire circuit at +5v.