Hi Peter, On Tue, 10 Mar 2020 at 09:03, pgraf--- via Ql-Users < ql-users@lists.q-v-d.com> wrote:
> > Anyway, it's working now... got about 30Kbit throughput between the Q68 > and > > a BBQL with GC, which is about the expected rate given the fact that > QLnet > > is half-duplex. SERnet between Q68 and PC is about twice as fast at > 115200 > > baud, but as I said it's easier to do bulk transfers by swapping SDHC > > cards. At least my BBQLs now have easy access to real mass-storage :-). > > Glad it works for you. Only 30 Kbit sounds a bit low, was that with > mass storage or ramdisk? > This was by copying a file (unzip) of 111158 bytes from ramdisk on Q68 to ramdisk on BBQL+GC, which took about 29 seconds from Q68 to BBQL. The other way round was a bit faster, 22 seconds so about 5000 cps. But copying from Q68 to BBQL with Trump card took 41 seconds, so processor speed does play a role. On my Issue 5 (JM) QLs I couldn't get the network to work. I apparently made a mistake in converting cps to bps, as the bytes on QLnet seem to be sent with a gap of 5 bits so I should multiply by 13 to get bps, which yields around 65Kbps. The theoretical limit would be 1bit/11.2us = 90Kbps but the network protocol will have a significant overhead caused by the small packet size (256 bytes) which means you lose a lot of throughput since the sender has to wait for an ACK every 256 bytes. Even on SERnet (which is full-duplex) this is an issue and also the reason why protocols like XMODEM has a poor performance on high-speed modem lines. On the other hand, streaming protocols like ZMODEM perform very well if there is proper flow control on your serial link but fail miserably when there isn't... Jan -- *Jan Bredenbeek* | Hilversum, NL | j...@bredenbeek.net _______________________________________________ QL-Users Mailing List
