IBM PC 5150 with no drives?

From: Fred Cisin <>
Date: Mon Mar 15 11:25:27 1999

Light pen interface was built in on the video board. Both CGA and MDP
(Monochrome Display and Printer) boards had it. But IBM didn't sell a
light pen, largely because the long persistence phosphor of the IBM
monochrome monitor made it unusable.

Clock and calendar were not on the motherboard until the AT. MS-DOS
would ask for DATE and TIME unless you had an AUTOEXEC.BAT file. Unless
you told it otherwise, it assumed that the date was 1/1/80.

Multifunction cards with disk controller, or video came much later. (~85)

The remaining "functions" to fill out the claimed numbers were software
in the box. Usually a RAM disk program and a print spooler. Thus, a
typical "SIX function" muyltifunction board would consist of Clock/calendar,
memory, serial, parallel, and two programs.
Received on Mon Mar 15 1999 - 11:25:27 GMT

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