The W5100 has the undocumented feature to wrap around the Address Register on an Auto-Increment at the end of physical address space to its beginning.
However, the only way to make use of that feature is to have only a single socket that uses all of the W5100 physical address space. But having only a single socket by defining SINGLE_SOCKET comes with downsides too:
One mustn't call into IP65 network functions anymore after w5100_config(). Additionally the program doesn't support 'W5100 Shared Access' anymore (https://github.com/a2retrosystems/uthernet2/wiki/W5100-Shared-Access).
If the user fails to set the disk tool variable(s) he now doesn't get syntactically wrong commands but rather file-not-founds. Maybe he even chooses to drop tool(s) into the current directory or add the disk tool path(s) to the PATH variable...
Omitting the middle digit because it is '0' must only be done if the high digit was omitted too (because it was '0'). If the high digit is '1' or '2' (and therefore not omitted) then the middle digit must never be omitted.
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.
Now that we have per-target combo driver wrappers we can remove the W5100 support from the C64. There isn't any actual (known) W5100-based solution for the C64.
The set of relevant drivers is after all different for each target. Building the combo driver wrapper individually opens the option to use .ifdef's to only include the drivers relevant for a certain target.
After all the Ethernet cards/carts are different enough to ask for customized drivers. Building the drivers individually opens the option to use .ifdef's to customize them.
parse_url stores the URL selector in the output_buffer - which is currently 520 bytes. A new entry point called parse_url_buffer was added which instead stores the URL selector in a buffer provided by the user.
url_download now calls the new parse_url_buffer instead of parse_url. The buffer for the URL selector is simply the download_buffer. So the download_buffer is used twice: First to hold the URL selector to be sent as request to the server and then to hold the response received from the server.
However, the URL selector still can't exceed the MSS (aka 1460 bytes).
Note: The User-Agent string was shortened by two bytes as that allows a "default" URL (incl. 'http://' but without port number) of exactly 1400 bytes to end up as 1460 bytes URL selector.
Tweet65 is sample application for triggering an IFTTT maker webhook. If ~450 chars are not enough for the URL then either the IP65 output_buffer needs to be increased or url_parse needs to be modified to use a different buffer. E.g. when called from url_download then the url_download_buffer could be temporarily used to hold the selector.
Note: The URL selector is stored in the output_buffer - which is currently 520 bytes. Beside all of the URL (apart from a potential "http://") the 'get' and the 'http_preamble' have to fit into that buffer. Therefore URLs mustn't exceed 450 chars. However, we omit a check to avoid further code size increase as most of the time URLs are known to be much shorter anyhow. If the URLs might become large we just leave it up to the user to check their length.
Beside the code for the actual feature this change introduces analysis of the URL to extract a potential filename to be used for saving. Doing so was a prerequisite for disk download because the filename extension in the URL is the only hint for distinguishing ProDOS sector order disk images from DOS 3.3 sector order images.
So far only the URL input was potentially repeated. Now the file input is potentially repeated as well. For normal file paths there's deliberately still no check. But when entering a drive specifier ("!Sx,Dx") then it is checked for plausibility - and there's an additional confirmation question to keep the user from overwriting the "wrong" disk.
With now having both the URL and file input potentially repeated it became clear that loading and saving the input history shouldn't be repeated - and if the user quits without having entered a valid input the history deliberately isn't saved at all.
So far we were reading (much) more bytes from the W5100 than necessary when processing the HTTP header. The byte were memmove'd to the beginning of the buffer.
However, when downloading a DOS 3.3 sector order disk image (*.dsk / *.do) then we need to place every DOS 3.3 sector at a certain point in the buffer to avoid additional memcpy's later. Therefore the HTTP header processing mustn't read (or rather commit) any body bytes from the W5100. So we now just check for the "\r\n\r\n" after each and every byte. This is of course less than optimal but small/simple - and the header isn't supposed to be that large anyway.
