Missing characters on throughput
#7
I've got a V1 WiModem232 and have done quite a bit of programming for a telnet client on an 8 bit computer. I too at times was dropping characters, and there are a number of times I was scratching my head trying to figure out why.

it all really depends upon the quality of the code in the telnet client. If ANSI is being displayed, then there is a lot more code involved than just putting up a character on the screen. There is also the issue of whether the client is properly enabling flow control with the hardware. On the computers I deal with, there are 3 different types of RS232's. At the hardware level, that interface is handled differently.

Besides ANSI and needing to make sure the serial interface was going on, there were 2 other factors I had to deal with. Unless you have hardware scrolling with your video, on my system I have to read what is on the screen and rewrite the screen offset by width of the screen's width to move the screen up one line. There are various tricks one can use to speed up that aspect if you simultaneously buffer text in CPU rather than do a video read/video write, you are just doing a CPU to Video write. You can also use multiple (40 in my case), multiple video write statements in a row before decrementing a loop counter.

Finally, when I thought there was still an issue, it turned out I had a buffer size issue. I run a BBS (9640news.ddns.net:9640) and there is one point when one looks for new files, it checks each category. Well, the BBS can run really fast and I have over 200 areas, and the telnet client was grabbing all the characters, however I had enough bytes coming in and I was overwriting my ~12K buffer loop. Never an issue with a BBS that had but a couple of thousand bytes coming in, but when I hit a large amount running at 38,400 baud, it did not take long to loop.

Not knowing your clients, I would investigate the size of the receive buffer as that may be the only thing you can personally control in the client besides enabling hardware control if you are wired up properly for it.

My 2 cents.
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Messages In This Thread
Missing characters on throughput - by Baldrick - 11-21-2018, 10:01 AM
RE: Missing characters on throughput - by admin - 11-21-2018, 03:45 PM
RE: Missing characters on throughput - by admin - 11-21-2018, 05:33 PM
RE: Missing characters on throughput - by admin - 11-27-2018, 12:03 AM
RE: Missing characters on throughput - by Beery Miller - 11-29-2018, 11:10 AM
RE: Missing characters on throughput - by admin - 11-29-2018, 12:46 PM
RE: Missing characters on throughput - by admin - 01-25-2019, 02:23 PM



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