18 Mar
2001
18 Mar
'01
4:03 a.m.
At 10:03 PM 3/15/01 -0500, you wrote:
MOST of the non-IBM MS DOS machines could take up to 768k of RAM. The
Sanyo 550 and Zenith Z-100s both did. AFIK there's no limitations on using
that memory. I used the 768k in my Sanyo as normal RAM with no problems.
Both the Z-100 and Sanyo also had vendor specific MS-DOS and went to at
least version 2.11. I think they both went to DOS 3.1 or so but I'm not
positive about that. The Z-100 had separate video memory but the Sanyo used
part of it main RAM for video. That was one of the biggest reasons that it
wasn't IBM compatible. However Sanyo later came out with a plug in video
card that made the 550 video compatible with the IBM. You had to load a
device driver to re-direct the video to the card and you could then get
video output from both the standard video port and the port on the vdeo card.
Joe
Other non -PC
hardware such as Rainbow went out to 896k and some of the
S100
based machines did the full meg using shadow rom.
Two Tandy products that come to mind that could be take up to
768k are the Model 2000 and the 1000HX. The only real benefit for
doing it on either of them was for RAM disks though. Like the PCjr,
the 1000HX used part of it's RAM for the video adapter as well. Both
shipped with thier own specific versions of DOS 2.11.