DGilbert.ES@XEROX.ARPA (05/08/85)
A recent file was distributed outlining the CHECKSUM and CRC protocol used in the modem7 (CHRISTENSEN) program series. It was named MODMPROT.003. This was great, as I was working on a modem program to be compatable with these protocols. However, it was missing the BATCH protocol. Is there any documentation on the BATCH protocol commonly used in modem7? The file names are transferred as well as the data for each file. This is the most useful protocol for mass transfers between machines. Doug.
caf@omen.UUCP (Chuck Forsberg WA7KGX) (05/12/85)
> A recent file was distributed outlining the CHECKSUM and CRC protocol used > in the modem7 (CHRISTENSEN) program series. It was named MODMPROT.003. > This was great, as I was working on a modem program to be compatable with > these protocols. However, it was missing the BATCH protocol. > Is there any documentation on the BATCH protocol commonly used in modem7? > The file names are transferred as well as the data for each file. > This is the most useful protocol for mass transfers between machines. The MODEM7 batch protocol has many problems besides being tied too closely to CP/M filenamne conventions, to wit: 03-Mar-85 19:54:22 Fm: Ward Christensen 76703,302 To: Paul Ferrara 70075,252 Modem7 batch was pretty poorly implemented ... complaint was that a character-by-character echo was used, which is not a generally recognized technique. It should instead have been something like Forsberg uses with YAM - a block 0 with the filename. I have had transfers drive me nuts, because the other end echoing the outgoing filename causes enough distortion that it tried, and tried, and tried, and tried.. but when it finally made it, the FILE itself made it with no hitch. The weakness was the echoing. I posted an article recently concerning the availibility of the YMODEM spec that Ward is writing up for an article in Byte. If there is sufficient demand, I will post the file to net.sources or somewhere directly. -- Chuck Forsberg WA7KGX ..!tektronix!reed!omen!caf Omen Technology Inc 17505-V NW Sauvie IS RD Portland OR 97231 Voice: 503-621-3406 Modem: 503-621-3746 (Hit CR's for speed detect)