From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: To: 9fans@9fans.net Date: Fri, 9 Oct 2009 20:25:09 +0200 From: lucio@proxima.alt.za In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Subject: Re: [9fans] /sys/include/ip.h 5c(1) Topicbox-Message-UUID: 8438caae-ead5-11e9-9d60-3106f5b1d025 > wikipedia agrees with lucio on this point > http://en.wikipedia.org/wiki/Micro_Channel_architecture#Marketshare_issues > >> The majority within IBM never wanted into that part of the market in the first >> place, as it was seen as cannibalizing not only 3XXX terminal sales, but the >> entire, highly profitable, big-iron+interface+network+services infrastructure >> behind said terminals. > > do you have a reference for this? There's truth on both sides, IBM had committed to the PC because Apple was stealing the show, but within IBM there were definitely movements keeping the PC at bay. My understanding was that the 8250, crappy UART that it was, was used specifically because SDLC required synchronous RS-232 and the 8250 didn't have it. Note that the 8251 was compatible with the 8088 (both Intel designs, if I'm not mistaken), where the 8250 came from National Semiconductors and required additional glue logic (and had write-only registers and no RESET, shudder!). Fact is, IBM had distinct, sometimes contrasting marketing objectives. I suspect that fighting the Taiwanese menace was as high on the agenda as anything could possibly get. In "Big Blues" (I think that is the book title) it is suggested that IBM did not have a proper focus and the PC was a knee-jerk reaction that should have been planned considerably better. ++L