Hello SMB-Builders,
i opened this thread for collecting hints and experiences around the building of a new SMB V2 board.
To this point i found the following issue:
- The silk screen for the LED D5 "System Tick" is reversed. All other LEDs on the SMB board are arranged with the flattened side to the little rectangle on the silkscreen.
- For older "non-IEEE" CPU boards you get no address display, because pSTVAL (pin25) is not connected or has PHI1 connected to it (In case of my Jade Big Z).
A workaround for these older CPU boards is to slip pin 13 of U10 out of the socket. The input is then high and gated the ADD-LATCH signal only from pSYNC. - The pulse rate from the "System Tick" circuit is for my board about 9,6 Hz with an 10uF tantalum and a 60pF trimmer. If you want exact 10Hz, you have to play around with C55.
Also i made a little drawing of the legends for the TIL311 board. Find it attached.
Frank