SoftICE DOS and A20

[T. Ment]

2.80 is the last DOS version of SoftICE.

I got it working on some AMD motherboards (vintage late 90s - early
2000s). But with Intel boards of the same era, it kept crashing when
trying to load lsl.com.

I found that changing BIOS setup A20 GATE from "fast" to "normal" made
the AMD boards crash too. My Intel boards don't have that setting, so it
seems they are equivalent to A20 GATE "normal" by default.

SoftICE limits extended memory to 16MB, and needs HIMEM.SYS from DOS
6.22 to work. Later HIMEM.SYS versions are not compatible.

HIMEM.SYS has a /MACHINE parameter. SoftICE says use the default value
of 1 (AT), but that only works for BIOS A20 GATE "fast." Since my Intel
boards don't have that setting, I tried the next /MACHINE value in the
list, PS2. And it worked.

Now I can use SoftICE DOS on my Intel boards too.

A20, what could be more fun.

[Robert Riebisch]

T. Ment wrote:

> SoftICE limits extended memory to 16MB, and needs HIMEM.SYS from DOS
> 6.22 to work. Later HIMEM.SYS versions are not compatible.

I ran Soft-ICE 2.8 with HIMEM 3.95 (from Windows 9x) successfully ten
years ago on a ThinkPad 770 laptop. (Probably also on a ASUS P5A
mainboard with AMD K6-2/550 CPU.)

DEVICE=D:\S-ICE\S-ICE.EXE /EMM 2048
DEVICE=C:\DOS\HIMEM.SYS /V

--
Robert Riebisch

[T. Ment]

Same here, but I also use Jack's UHDD.SYS and UDVD2.SYS. UDVD2 crashes
and pops up SoftICE with Win9x himem.sys. The older DOS 6.22 himem.sys
doesn't have that problem, because of its memory limit of 64MB.

SoftICE for DOS limits extended memory to 16MB anyway, so there's no
benefit with Win9x himem.sys. Maybe it works with WinICE, but I don't
need that yet. Maybe later.