The W5100 TCP driver is intentionally very similiar to the UDP driver. It comes with its own test program (again similiar to the UDP test program) and an extension to the communication peer program to support the test program.
In order to ease exploring the W5100 UDP driver a simple test program using it was added. Additionally a communication peer program was introduced. The latter builds as-is for Windows using i.e. the VC++ command line 'cl w5100_peer.c'.
The Apple 2 web server now uses the "combo" library and optionally uses a2_set_slot to scan all slots for the Ethernet card. Combining both with DHCP allows for complete auto configuration.
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.
Up to now every IP65 library contained exactly one Ethernet driver. In scenarios without strict memory limitations I might however be benefitial to have an IP65 library containing all Ethernet drivers available for a given target.
The Ethernet hardware detection that was already present before is used in this scenario to try to initialize one Ethernet driver after the other until one succeeds. If all drivers fail to initialize the user gets informed as usual.
The WIZ811MJ driver was primarily introduced for orthogonality reasons. There are however at least two W5100-based prototypes for the C64 so it makes at least some sense. The name was chosen as sort of placeholder for "something containing a W5100 chip".
The HTTPD program seems to be the only one somewhat useful for demo purposes. So I added the option to build a "IP65demo" disk containing it for all supported Ethernet devices - currently for the Apple2 only.
Behave just like the CS8900A driver: Both the CS8900A and the LAN91C96 dynamically share a buffer for received packets and packets to be send. If the chip is exposed to a network with a lot of broadcasts the shared buffer might fill quicker with received packets than the 6502 reads them (via polling). So we might need to drop some received packets in order to be able to send anything at all.
Of course one can just always call dns_resolve after dns_set_hostname. But an application might i.e. present a different user feedback depending on the fact if a name resolution is necessary at all. So given that DNS name resolution is already a two phase action it just seems natural to allow an application to read the already exsisting variable.
The pretty small check_for_abort_key is used by DHCP and DNS which means it is used by about every IP65 program. The pretty large get_filtered_input on the other hand is very seldom used so it makes sense to put the latter in a separate module to keep it from ending up in binaries unused.
The previous chip detection was inspired by the old IP65 driver code. For some reason it didn't work as expected. The new code is simpler and based on this statement in the chip datasheet: "The upper byte always reads as 33h and can be used to help determine the I/O location of the LAN91C96."
* 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.
I have no idea why this BRK was put there in the first place. At least nowadays it's pretty common to see IP packets that IP65 doesn't understand / need to understand. Just think of IGMP packets. We certainly don't want to crash on receiving those!
It's the very purpose of the DATA segment to consolidate all items that potentially need to be copied from ROM to RAM. So there's no need to / point in doing that on a per-item-base.
This file isn't technically related to ip65. It uses the W5100 IP stack to implement UDP frame RX/TX. The code heavily optimized for size (in contrast to speed).
