Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!ptsfa!ames!oliveb!gnome From: gnome@oliveb.UUCP Newsgroups: comp.sys.att,comp.sys.ibm.pc Subject: Re: 6300 16-bit I/O port botch: Could Olivetti ... Message-ID: <1861@oliveb.UUCP> Date: Tue, 7-Jul-87 16:21:03 EDT Article-I.D.: oliveb.1861 Posted: Tue Jul 7 16:21:03 1987 Date-Received: Fri, 10-Jul-87 02:12:06 EDT References: <220@amanue.UUCP> Organization: Olivetti ATC; Cupertino, Ca Lines: 25 Xref: utgpu comp.sys.att:587 comp.sys.ibm.pc:4739 in article <220@amanue.UUCP>, jr@amanue.UUCP (Jim Rosenberg) says: > Xref: oliveb comp.sys.att:644 comp.sys.ibm.pc:5146 > controller") outputs the two bytes to the bus **IN THE WRONG ORDER**!! That > means **ANY** 16-bit output instruction to a card on the bus will get the > bytes swapped. Software that does only 8-bit OUT instructions to the ports on > the EGA will work, but anything that does 16-bit OUT instructions won't. > -- > Jim Rosenberg Oh well, that is because it was built two years before the AT came out! If you are going to do 16-bit I/O's to an 8-bit device, something has to decide the byte-order, and when the 6300 was designed, there certainly weren't any "standards" to be followed. I have heard of a couple of boards/drivers that use 16-bit I/O and depend on the first byte being stomped-on by the second byte. The first byte contains relatively useless data, which which get immediately overwritten by the second. Not a smart programming move. The bus supports full 16-bit I/O, with the second 16-bit connector (which is NOT an AT format connector, for the same reason listed above). Since you are having to use existing software and hardware, then you are stuck, I would think. Gary