CompuServe Thread

#Download Times

6 messages in this thread
#46768From: steven wheelerJan 2, 1987 2:39 AM
HELP!!! I am a new user on this system and am confused. I attempted to download 'JUGLER.ARC' after reading about it in the bulletins. After about 3 hours of downloading , I gave up and aborted the download function. I am running 'ONLINE' software with an Avatek 1200 modem, at 1200 baud. Am I doing something wrong? Or is this exorbiant amount of time normal. If it is normal, is this program really worth over $40.00 of charges to download it I would greatly appreciate any info anyone can give me. Also, how do I find out the specifics about different download protocols, technical specifics please. Thanks Steve Wheeler
#46774From: Steve AhlstromJan 2, 1987 3:16 AM
At 1200 baud JUGLER.ARC should take approximately 90 minutes to download.
#46776From: Don Curtis/SYSOPJan 2, 1987 3:21 AM
Steve, You were caught between a rock and a hard place. You had already spend the 3 hrs connect time, but now have nothing to show for it, but by the same token, didn't want to spend more time downloading it. I downloaded it at 2400 baud in 50 minutes, and friend downloaded it in 1.75 hrs at 1200 baud, but we both did it late at night. Depending on system usage, the times can vary widely. The best way to determine how long a file is going to take is to figure out how big it is and what the baud rate is. The size is no problem…it's given in the description of the file as the number inside the parenthesis (or if only 1 number..then the number itself). Now this number is always a little high, but is a good starting place. Divide that number by 128 and you get the number of Xmodem blocks or divide by 512 and you get the number of B-Protocol blocks approxitmately. Under ideal conditions (very rare!) you can get 1 block of Xmodem (128bytes + 4 or 5 protocol bytes) in about 1.2 seconds. Double that. and you'll get an approxitmation of time under fair to poor conditions. Under heavy usage…it might be slower, under low usage, it will be faster. To get an idea of system usage, before the download, do a UST. Look at how many folks are in ACCESS. If a large number, it would be a good idea to wait. The best time is usually after 1:00am Eastern time. So, if the number in parenthesis shows the file to be 128,000 bytes long, it will take about 1000 Xmodem blocks to download it. At 1.2 seconds per block that would be 1200 seconds. Doubling makes that 2400 seconds or 40 minutes. So the 3 hrs time must have been during quite heavy usage as it was almost double my friend's time for the same download. The terminal program can also play a factor depending on how often it writes to the disk (this can easily double the time again if it writes every block it gets to disk as it gets it) so we suggest you download to RAM: and then copy to a disk. B-Protocol is generally 10 – 15 % faster in downloading. Don
#46814From: steven wheelerJan 2, 1987 1:28 PM
Thanks, you really cleared up my confusion. I have been heavily involved with programming for test equipment for Rockwell Int. and have never done much in the way of telecommunications. I guess my ignorance is showing. I noticed that you did not comment on the last part of my message, the query about where I would find information on the different protocols such as the 'Compuserve -B-' protocol. Am I treading in an area that is taboo? I am giving thought to writing my own terminal program, but without this info it won't bre worth much. Either way, thanks again for the assist. And thanks to your fellow sysop. PS:Does everyone have as much trouble typing text in as I do, I've never seen as many spelling mistakes as I'm making.
#46856From: Dan MooreJan 2, 1987 5:34 PM
The doc for CIS B protocol can by found by typing "GO VIDTEX". Follow the menus down and there is a doc file on the format and some sample C source on how to implement it. Dan
#46862From: Barry KucherJan 2, 1987 5:52 PM
One more thing about downloads. If you are using WB 1.2 watch out how long the files are you are sending to the RAM: disk! I was downloading the Page Setter Demo and my ram disk filled up after about 1000 Xmodem blocks For big files I will spend the extra time & download to DF1: even though it might take longer, I know it won't fill up. One question for anyone out there. How big is the RAM: disk under 1.2 or should I say how big can it get?