Erik Labs Releases BIMODEM, a New File Transfer Protocol that allows, among other things, the ability to upload and download at the same time, and initiate chats during the file transfer. The protocol usually presents itself as an external program that is called by a BBS.
BiModem is a new communications protocol which allows simultaneous
bidirectional file transfers. Yes, BiModem can upload while
downloading. Imagine the time savings if you could upload with
Zmodem (tm) and YmodemG efficiencies while downloading at the same
efficiency at the same time. The applications for such a protocal
are many, and I will not try to cover them here. Everyone from
occasional BBS users to fulltime network managers will appreciate
the advantages of exploiting full duplex operations. Even for those
with small and moderate volumes of data to transfer the time
savings can be very significant. Please do not expect a 50%
decrease in your overall modem transfer time. This can only be
achieved when the same amount of information is transmitted in both
directions, and does not account for the overhead of specifying the
lists of files to download and upload.
If that feature is not enough to get you really excited, how about
the ability to chat while the transfer is going on? Chatting, of
course, will impact your throughput, but since most of us are slow
typists, when compared to the speed of even a 1200 baud modem, the
impact is usually minimal.
Automatic recovery looks in your download directory for a file with
the same name and date, and upon finding it verifies the contents
for accuracy with the original file. This takes about 20 seconds
per 200k at 2400 baud. It then continues the download at the point
where it left off.
Refresh mode uploading is similar to automatic recovery, but the
date does not need to be the same. This is perfect for large
transaction files where the only thing that ever changes is at the
end of the file where transactions are added. Imagine refreshing a
10 meg file in a few minutes that only had 20k modified at the end.
Auto Verification insures that the entire file was accurately
transmited can be switched on at the users discretion. While this
is normally not nessessary (BiModem already uses 32bit CRC's to
insure accuracy), it is a nice feature to have available for those
critical transmissions and is efficient enough that you may want to
use it routinely.
BiModem has more than just * name handling. You can create a large
list of upload and download request before you even sign on. Create
an entire evening's worth of requests and let your computer do the