The RR-Net MK3 can be operated in two modes:
- In cartrigde mode it has a startup-ROM that sets the CS8900A MAC address to the unique MAC address.
- In clockport mode the driver has to read the two lowest MAC address bytes from the EEPROM and combine them with 28:CD:4C:FF.
See http://wiki.icomp.de/wiki/RR-Net#Detecting_MK3 for details.
The driver first checks if the current CS8900A MAC address starts with 28:CD:4C:FF. If it does, it overwrites its built in default MAC address with the CS8900A MAC address.
If the CS8900A MAC address didn't start with 28:CD:4C:FF, it checks if there are two valid MAC address bytes in the EEPROM. If they are there, it overwrites its built in default MAC address with a combination of 28:CD:4C:FF and those two bytes.
So far the base address of the Ethernet chip was a general property of all Ethernet drivers. It served two purposes:
1. Allowing to use a single Ethernet driver for a certain Ethernet chip, no matter what machine was connected to the chip.
2. Allowing use an Ethernet card in all Apple II slots.
However, we now use customized Ethernet drivers for the individual machines so 1.) isn't relevant anymore. In fact one wants to omit the overhead of a runtime-adjustable base address where it isn't needed.
So only the Apple II slots are left. But this should rather be a driver-internal approach then. We should just hand the driver the slot number the user wants to use and have the driver do its thing.
Independently from the aspect if the driver parameter is a base address or a slot number the parameter handling was changed too. For asm programs there was so far a specific init function to be called prior to the main init function if it was desired to chnage the parameter default. This was done to keep the main init function backward compatible. But now that the parameter (now the slot number) is only used on the Apple II anyhow it seems reasonable to drop the specific init function again and just provide the parameter to the main init function. All C64-only user code can stay as-is. Only Apple II user code needs to by adjusted. Please note that this change only affects asm programs, C programs always used a single init function with the Apple II slot number as parameter.
There are scenarios in which it is beneficial to search for an Etherne chip at several i/o locations. To do so the chip initialization is performed at several i/o locations until it succeeds. In order to allow for that operation model the i/o location fixup needs to be repeatable.
Note: This won't work with the RR-Net because the fixup bits overlap with the chip i/o bits.
* CS8900A
The Contiki driver allows to adjust the chip base addr at runtime (which allows to support different slots in the Apple II) and removes received frames from the chip if there's no room to send frames.
* LAN91C96
The Contiki driver was used by IP65 more or less unchanged in the first place.
* W5100
The Contiki driver allows to adjust the chip base addr at runtime (which allows to support different slots in the Apple II) and stays clear from the W5100 hybrid mode. It presumes a fully functional W5100 register auto-increment and pre-calculates necessary W5100 frame buffer wrap-arounds and thus achieves the maximal 6502 <-> W5100 transfer speed.
- Tab chars were partially used with the unusual width of two blanks. I removed them altogether.
- Line endings were inconsistent even iniside individual files. I normalized them.
- I introduced a consistent coding style regarding comment indenting and blank line usage.
- I removed trailing spaces.
- I removed newlines following unnamed labels.
- ...
