Hi all
Can someone recommend a good document detailing the workings of the expansion port? I especially would like a description of what happens when the machine is first switched on.
thanks
Quote from: StyleCHM on January 14, 2008, 10:40 AM
Hi all
Can someone recommend a good document detailing the workings of the expansion port? I especially would like a description of what happens when the machine is first switched on.
thanks
There is a ton of information on this one subject, which may be tracked down via use of of any search engine. You can also look at official Commodore documentation, books such as
Mapping the Commodore 128, etc.
Most of the documentation Ive found simply lists the pinout of the connector.
I guess I could get the CRO out and trace it out myself, but that smacks of effort :D
Quote from: StyleCHM on January 14, 2008, 12:42 PM
Most of the documentation Ive found simply lists the pinout of the connector.
I guess I could get the CRO out and trace it out myself, but that smacks of effort :D
Effort is rewarded with knowledge. No slacking allowed around here!
Just found a page which answers some of my questions:
http://ist.uwaterloo.ca/~schepers/MJK/expansion_port.html (http://ist.uwaterloo.ca/~schepers/MJK/expansion_port.html)
specifically
"RESET. When going LOW, the CPU resets and waits for a LOW-HIGH transistion to load the PC with the value stored in $fffc/$fffd. After power-up, timer A in the NE556 pulls this line to LOW for a short time and half a second later back to HIGH."