| ??? 04/19/07 02:29 Read: times |
#137494 - suggestions Responding to: ???'s previous message |
Jerry Black said:
...driven by 74hc573(shift latch register).
I agree with the rest of the people here. The 74HC573 is an 8-bit latch. I happen to like it better than the 74HC373 because the pin configuration is much easier to deal with. It is not a shift register. but the chip that drivers the display is an unknown 40 pin chip.Standard power config (20 GND 21 VCC). I agree with one poster that pin 20 for ground and pin 21 for VCC is not standard. The reason why he suggested pin 40 as VCC and pin 20 as ground is because many digital chips follow a common format that VCC is at the top left of the chip and GND is at the bottom right. Each side of a DIP chip has half the total number of pins. Pins start from bottom left to bottom right then from top right to top left. therefore, the top-left pin in a 40-pin DIP is VCC and the bottom-right pin in a 40-pin DIP is GND. Make sure that the indentation that the DIP chip has is on the left side. some have 1/2 circles carved out, and some have circles which look as if part of the chip has been carved. To best explain it, look at the black parts on a standard set of dice. If it is true that pin 20 is ground and Pin 21 is VCC, then it is most likely an analog chip. It does NOT have any external clock line(Not that I could see) and it controls the display and manages the button inputs. it's got copyrights from Intel and Phillips. The main processor is an 80c31. I put my scope on the 80c31 and it seems to be firing up just fine.it looks the the 80c31 directly connects to the mystery chip. I googled the He** out of the numbers on the chip. No go. 282-10050 looks like a Newell part number. Did you contact Phillips and Intel directly? Maybe scan the chip and send the picture of the scan to them through E-mail. |
