Hi,

Reading your schematic diagram I found two mistakes. The OE pins of your RAM and ROM must be tied to the inverted R/!W of the 6502 nanded with the phi2 clock.


_________ _________
| 1| | &|
R/!W -------| |O--------------| |
|_______| | |O-------- !RD
| |
PHI2 ...

My SPI display has in SPI the following lines: CS, CLK and MOSI. Without CS the display won't work. I assumed that it is the same as on your display. The delays in write only mode are needed as John West told already.
I hope after changing the instruction given by him and using the given delays it ...

Hi,

I think you are confusing some things.

When using SPI you need to know the following:
MOSI (Master Out Slave In) is the bit output from CPU to the LCD, MISO (Master IN Slave Out) is the bit input from the LCD to the CPU. CLK is the shift clock output to the display, CS is the chipselect for ...

This is the corrected version, thanks to Handyandy. Remarks still welcome.

Hello,

I'm Nick and have a lot of experience building 68xx and Z80 microcomputers. I found a 65C816 while cleaning up my hobby-room. I tried to design a schematic that should give a working computer, but after reading some posts in this forum I am confused. I think it will not work at all. See ...