CompuServe Messages

Hardware Questions

    20-Nov-89 22:45:14
Sb: Hardware Questions
Fm: JAMEE MIKELL 73537,2663
To: ALL
I'm working on a project and need to know a few things I can't find in any of my sources. 1) What do the following lines do on the A2000 CPU slot? a) /COPCFG (pin 11) b) /BOSS (pin 20) 2) Is there any phase relationship between the 28 MHz clock on the A2000 CPU slot and the 7 MHz system clock. (i.e. does the 7 MHz clock start or end on one of the edges of the 28 MHz clock? In the middle of the cycle? Insignificant where it is in relation to the 28 MHz clock? etc.) 3) What does the Zorro 2 line DOE (pin 93) do? Is it important? Does anything use it? 4) What do /OVR and XRDY (pins 17 and 18 on all expansion interfaces) do? 5) Finally … Is there any way a normal person can arrange to get a 4-layer PC board etched without having to pay an arm and a leg and his firstborn son? (It would significantly reduce the size of the project.)