[Coco] 6809 FPGA

[Bill Nobel]

Hey all, as some of you know I have been porting Grant Searles project to my DE0-Nano.  I have it working with internal ram on the Nano itself with 32k ram.  I got my 512k SRAMs from Digikey a week ago, (wired as 64k)  when I try to use the SRAM instead of the internal RAM  I lose the PS/2 keyboard input.  I get the ‘6809 EXTENDED BASIC’ banner, and ‘OK’ prompt. but no keyboard.  This is running it at 10mhz.  On internal RAM I can do 25mhz no problem.

For the SRAM I have it going to IOBANKS 7 & 8. SRAM address bus & chip selects on bank 8 and SRAM data on bank 7.  Video & PS/2 I have on bank 5.

Any suggestions would be helpful

Bill Nobel