Int 13h buffer 64k boundaries

Guy Sotomayor Jr ggs at
Fri Apr 20 00:08:39 CDT 2018

> On Apr 19, 2018, at 8:55 PM, Chuck Guzis via cctalk <cctalk at> wrote:
> On 04/19/2018 07:56 PM, Guy Sotomayor Jr wrote:
>> As to why IBM entered the PC market, the rumor was (at least at the time
>> within IBM) was that T.J. Watson, Jr. was at an employee’s house and saw
>> an Apple II.  He said that he wanted to have IBM branded computers in IBM
>> employees homes.  That was how the IBM PC project was kicked off.
> But it wasn't clear at all what IBM intended the PC for.  Cassette tape,
> TV interface and anything but state-of-the-art design
> The best part of the 5150 IMOHO, was the keyboard.

It was a variant of the keyboard that was used on the System/23.  The basic
keyboard technology was used in a lot of IBM keyboards at the time.


> My general impression is that IBM made the 5150 product, without the
> faintest idea of how they were going to sell it.

It was IBM’s answer to the Apple II and various S-100 systems so it was
stripped down for a “low” entry price and/or added with other stuff.  It was
designed to be easy to interface to so that others could make peripherals.

It was really following the model of what other “home” computers at the
time were doing.  It was also a bit of an experiment and in that respect
you’re correct.  They didn’t know what it would be used for nor how to
sell it as it was *so* far outside of the normal IBM product lines.

TTFN - Guy

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