28 Jan
2008
28 Jan
'08
8:07 p.m.
Date: Mon, 28 Jan 2008 15:40:04 -0600
From: Jim Leonard <trixter at oldskool.org>
- Manipulate the speaker to produce arbitrary tones
- Update the screen in arbitrary locations (text mode; multiple screen
pages if available) - Get single-key input from the user, including
sensing keypresses from "inert" keys like shift and capslock (by
themselves as well as in conjunction with other keypresses)
It depends on what you want to call "MS-DOS ompatible". NEC 9801
series machines have a completely different I/O port and memory
layout; the CRT controller is a world unto itself and the BIOS
interface is different. But the things run MS-DOS, albeit with 1,024
byte sector diskettes, and have an x86 CPU in them--some with Intel;
others with NEC V-series CPUs. I think the family went as far as a
486 equivalent.
For that matter, I believe a number of configurations of the S-100
Compupro boxes could run MS-DOS.
I know of other MS-DOS compatible machines that do not have memory-
mapped displays but rather interface to a serial terminal (no
graphics capabilities). There are others with non-PC memory layouts
that will give you most of a megabyte of contiguous RAM to work with.
My point is, that "MS-DOS compatible" covers a huge amount of
territory. On the other hand, "something that will boot from a PC-
DOS 3.31 diskette" is quite a bit more restrictive.
FWIW,
Chuck