[rescue] Apple to ditch IBM, switch to Intel chips

Geoffrey S. Mendelson gsm at mendelson.com
Mon Jun 6 00:48:05 CDT 2005

On Sun, Jun 05, 2005 at 01:59:03PM -0400, Charles Shannon Hendrix wrote:
> Back in the 80s, you almost never heard about clock speed.  It was all
> about which programs would run, a few questions about graphics, and
> wether or not Printshop would run on it... :)

That's because there were a lot less options. There was the PC at 4.7mHz
which became the PC/XT, which was the system that everyone copied, as in
COMPATIBLES and clones. The XT clones were available later as fast as 8mHz,
but they were unreliable writing floppies at that speed.

IBM was going to come out with an 8mHz 80286 machine called the PC/AT
which was almost three times the "power" of the XT, but Intel could not
deliver and the PC/AT came out with a 6mHz clock. Some early AT's could
be overclocked at 8Mhz and even a rare few at 10mHz, and IBM made
changes to BIOS to prevent it as they were often unreliable.

The Macintosh came with one speed, 16mHz, along with its later similar
systems the Atari ST (aka "Jackintosh") and the Amiga. When Apple produuced
the Mac II it was still 16mHz with a 68020 processor for faster performance,

The Mac II became the IIx with a 68030 and was cloned into a little beige
box as the SE/30, but they stayed at 16mHz.

In the PC market it wasn't until the late 80's that IBM produced the
PS/2 with faster 80286 processors, but they were microchannel. By that time
the clone makers had gotten their hands on faster 80286 processors
and before its demise the 80286 got as fast as 20mHz, but by then the
80386 had come out.

The 80386 was a landmark chip for Intel as it had real protected memory
with virtual addressing and linear address space. This made it relatively
easy to port UNIX to it, and gave rise to several versions of UNIX,
AT&T and it's children, SunOS, Linux, the free BSDs, etc. But I
digress as if memory serves, we were now into the 90's.


Geoffrey S. Mendelson, Jerusalem, Israel gsm at mendelson.com  N3OWJ/4X1GM
IL Voice: (077)-424-1667  IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 
VoN  Skype: mendelsonfamily. Looking for work as a CTO or consultant in 
handheld gaming, large systems development, handheld device construction, etc.
See U.S. patent applications  20050108591,  20050107165.

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