Subject: Re: [stella] Chip Select Line From: mickey_m@xxxxxxxxx Date: Sun, 12 Jan 2003 00:56:57 +0000 |
The 7407 is an open-collector device. It needs to be pulled high. Do you do that? I dont think timing is your issue, the 7407 is rated at 27ns max, it shouldnt skew the A12 enough to mess up setup times and stuff. I know it sounds basic, but sometimes I miss them the most. But then again, I am a programmer, so there is a good chance I dont know what I am talking about. Vern > Hello ! > > I have made a little testing with an original PacMan ROM chip. > I made all the lines available for measuring the signals. > > If I connect all lines to the PacMan ROM, as in the original cartridge, > everything works fine. > > What I did now is, that I connected the A12 line to an 7407 buffer and from the > output of that buffer back to the CS line o the ROM. It is not inverting, so it > should work. But it doesn't. Why not ? > > What are the timing requirements for the A12 line ? What am I missing ? > It should work, shouldn't it ? > > Kroko. > > > > > ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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