I printed a the foil patterns and got a more accurate view.
The chips on the bottom row are 6 74LS245's, from right to left, they provide Status, Data In, Data Out, A8-15, A0-7, Control. 3 more 14 pin chips are to the left, with VCC and GND. Holes are all down 50mil, Regulator has shifted to the right 100mil. Original Unbuffered board gave 45 rows, this buffered board gives 42 rows. Copper: Component Silk - Grids are 10 by 10 holes. The 5V for the LED is marked, 5V and GND available from right. The 7812 and 7912 Regulators are optional, if not installed, other chips can straddle the pads used. |