Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!rpi!uupsi!sunic!ugle.unit.no!nuug!ifi!torkell From: torkell@ifi.uio.no (Torkel Lodberg) Newsgroups: comp.sys.amiga.hardware Subject: Amiga serial hardware Message-ID: Date: 19 Feb 91 20:53:07 GMT Sender: torkell@ifi.uio.no (Torkel Lodberg) Organization: Dept. of Informatics, University of Oslo, Norway Lines: 29 Nntp-Posting-Host: kvart.ifi.uio.no Originator: torkell@kvart.ifi.uio.no The Amiga hardware has undergone many changes since the first A1000 was released. The custom chips have been changed several times, and a few custom chips have also been added. But... the serial hardware is still the same. Nothing has been done to improve it, although it is in a quite bad shape. Just forget about reliable transfers at anything more than 9600 baud. Even when CTS/RTS is being used, input still overflows. If you activate a window during a transfer at 38400 baud - or start disk activty - I can tell you that you will get at LEAST one error in the transfer. Oh well.. just forget about using the CIA B timer when using the serial port. About 25% of the input will get lost at 19200 baud. And hogging of the CPU will not be handled by the serial hardware. You will run into the same problems with DMA. According to Jack Radigan, even the "disk changed" checking will give you problems when using a couple of floppy drives combined with a hard disk. I have been told that the problem is due to "the internal port not being able to buffer multiple bytes". The Paula chip is supposed to be responsible for some of the problems. So: Will anything be done about the serial hardware in the near future? The A3000 still has the old silly serial hardware - wouldn't it be possible to include a 16550 chip or so on a future motherboard? T.Lodberg (quite tired of writing comms-software that will not work due to problems with the *hardware* :-(