Dirk Verwiebe wrote:

> Currently i am porting the colecovision core to my spartan board. It
> nearly works, i get the bios messages but
> roms(dkong) donīt work. I converted the rom file with hex2rom. I neednīt
> move the video ram to external ram
> because the rom fits into the fpga,too.
> The system doesnīt recognize the rom.
> Is there something special for connecting the rom ?

It's been a while, but looking at my source - the only 'special' part I did
was remove the 16->8 data mux (process cart_if) and wire the (8-bit)
cartridge ROM data output directly to cart_d_s. Use cart_a_s(13:0) for the
address part if you do the same.

I'm using external SRAM for the video RAM, and internal RAM (RO) for both
the BIOS and cartridge ROMs. I didn't use hex2rom because I have my own
utilities for converting binaries to hex/mif files that the Altera tools
require. Maybe hex2rom doesn't support 16-bit wide memory?

Regards,

--
| Mark McDougall | "Electrical Engineers do it
| <http://members.optushome.com.au/msmcdoug> | with less resistance!"