Difference between revisions of "Talk:83Plus:Ports:02"

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I've been looking into alot of the hardware and it doesn't look like bit 1 of port 2 is the inverse of the bit 7 of port 10. It looks more like a delay whenever the hardware is used. I compared the values I would get when polled the 2 ports and port 10 gave me quite a bit jitter when it came to the timing. Port 2 on the other hand I got no jitter at all. In fact I wrote to new lcd copy routine, one using port 2 and the other using port 10. On ther 83+(and SE @6mhz) Port 2 version updated faster. On the SE at 15mhz, port 10 version updated faster, while port 2 version was slower than 6mhz test was.  Thats enough to clearly say the bits aren't the same, But are used for the same purpose. --[[User:Jim e|Jim e]] 23:39, 30 Apr 2005 (PDT)
 
I've been looking into alot of the hardware and it doesn't look like bit 1 of port 2 is the inverse of the bit 7 of port 10. It looks more like a delay whenever the hardware is used. I compared the values I would get when polled the 2 ports and port 10 gave me quite a bit jitter when it came to the timing. Port 2 on the other hand I got no jitter at all. In fact I wrote to new lcd copy routine, one using port 2 and the other using port 10. On ther 83+(and SE @6mhz) Port 2 version updated faster. On the SE at 15mhz, port 10 version updated faster, while port 2 version was slower than 6mhz test was.  Thats enough to clearly say the bits aren't the same, But are used for the same purpose. --[[User:Jim e|Jim e]] 23:39, 30 Apr 2005 (PDT)
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:That bit seems to report things other than the LCD status.  On the BE, it determines whether the boot code will write to port 5 before writing to port 16.  (I have no idea what this means.) [[User:FloppusMaximus|FloppusMaximus]] 12:30, 1 May 2005 (PDT)

Revision as of 12:30, 1 May 2005

I've been looking into alot of the hardware and it doesn't look like bit 1 of port 2 is the inverse of the bit 7 of port 10. It looks more like a delay whenever the hardware is used. I compared the values I would get when polled the 2 ports and port 10 gave me quite a bit jitter when it came to the timing. Port 2 on the other hand I got no jitter at all. In fact I wrote to new lcd copy routine, one using port 2 and the other using port 10. On ther 83+(and SE @6mhz) Port 2 version updated faster. On the SE at 15mhz, port 10 version updated faster, while port 2 version was slower than 6mhz test was. Thats enough to clearly say the bits aren't the same, But are used for the same purpose. --Jim e 23:39, 30 Apr 2005 (PDT)

That bit seems to report things other than the LCD status. On the BE, it determines whether the boot code will write to port 5 before writing to port 16. (I have no idea what this means.) FloppusMaximus 12:30, 1 May 2005 (PDT)