MS-DOS player can now embed executables

So what this means is that now you can make fully standalone Win32/Win64 executables out of CLI based MS-DOS applications.

D:\tcc>msdos\binary\i486_x64\msdos.exe tcc -Iinclude -Llib hi.c
Turbo C++ Version 3.00 Copyright (c) 1992 Borland International
hi.c:
Turbo Link Version 5.0 Copyright (c) 1992 Borland International

Available memory 4215648

D:\tcc>c:msdos\binary\i486_x64\msdos.exe hi
hi!

D:\tcc>c:msdos\binary\i486_x64\msdos.exe -c hi.exe
‘new_exec_file.exe’ is successfully created

D:\tcc>new_exec_file.exe
hi!

Isn’t that great?

I’ve had one issue with Turbo C++ 3.00 and that is the embedded executable will run out of memory while linking, but invoking it by calling msdos.exe let’s it run fine. If you compile and link separately it’ll run just fine.

As always you can find the project page here:

http://homepage3.nifty.com/takeda-toshiya/msdos/

As requested, PCem v11 with networking

via SLiRP

via SLiRP

injecting networking was no more difficult than it was in version 10.  It’s only a few changes to pc.c, if you look at the USENETWORKING define you’ll see them.  The best notes are on the forum.

I haven’t changed or improved anything it still requires manual configuration.

Downloads are available on my site as pcem_v11_networking.7z.  You’ll have to defeat the password protection, as always.  I included the source, it ought to be trivial to rebuild.

*For anyone using an old version the ‘nvr’ directory is missing, so PC-em is unable to create new non volatile ram save files, meaning you always loose your BIOS settings.  Sorry I missed that one.

PCem v11 released

I haven’t had time to follow it, but great news!

PCem v11 released. Changes from v10.1 :

  • New machines added – Tandy 1000HX, Tandy 1000SL/2, Award 286 clone, IBM PS/1 model 2121
  • New graphics card – Hercules InColor
  • 3DFX recompiler – 2-4x speedup over previous emulation
  • Added Cyrix 6×86 emulation
  • Some optimisations to dynamic recompiler – typically around 10-15% improvement over v10, more when MMX used
  • Fixed broken 8088/8086 timing
  • Fixes to Mach64 and ViRGE 2D blitters
  • XT machines can now have less than 640kb RAM
  • Added IBM PS/1 audio card emulation
  • Added Adlib Gold surround module emulation
  • Fixes to PCjr/Tandy PSG emulation
  • GUS now in stereo
  • Numerous FDC changes – more drive types, FIFO emulation, better support of XDF images, better FDI support
  • CD-ROM changes – CD-ROM IDE channel now configurable, improved disc change handling, better volume control support
  • Now directly supports .ISO format for CD-ROM emulation
  • Fixed crash when using Direct3D output on Intel HD graphics
  • Various other fixes

Thanks to Battler, SA1988, leilei, Greatpsycho, John Elliott, RichardG867, ecksemmess and cooprocks123e for contributions towards this release.

Downloads are available for Windows & Linux.

FOOTBALL Design Document

Over at pcjs.org, this interesting prototype version of OS/2 has been unearthed.  What this means is that not only was there prototypes of a 386 aware version of OS/2 in 1986, but by 1987 the base of cruiser AKA OS/2 2.0 was already in place.  With this now somewhat made public, it really is clear that IBM’s meddling in OS/2 prevented it from being a success.

Check out the design document below:
The following text is from an email titled “3xBox Design Document” sent to the football alias on Saturday, February 28, 1987, at 5:02pm.

Overview

The goal for this research project was to demonstrate the feasability of supporting multiple virtual DOS 3.x machines on a 286DOS-based kernel running on an 386 personal computer. Each “3xBox” would have its own virtual screen, keyboard, interrupt vectors, and address space. Furthermore, well- behaved DOS 3.x applications that do text (as opposed to graphic) screen output would run in the background.

In order to acheive this goal in a reasonable amount of time, we started from the 286DOS “sizzle” kernel and made the minimum amount of changes necessary, both in code and fundamental design. The resulting DOS will be referred to as “386DOS” in this paper.

386DOS provides up to four 3xBoxes, depending upon the available RAM. More 3xBoxes could be supported if a slight change is made to the method of allocating page tables.

Well-behaved DOS 3.x applications (i.e., MS-Multiplan, MS-Word, Lotus 1-2-3) can run in the background, multi-tasking against one another and against the foreground screen group. Lotus 1-2-3 (version 2.01) passes its floppy-based copy protection when in the foreground.

It should be noted that 386DOS, while functional, is not an optimal design/implementation of multiple 3xBoxes. In particular, interrupt management, the device driver model, and the existence of V86-mode kernel code should be modified before 386DOS is made a commercial product.

Unless stated otherwise, most of the concepts extant in 286DOS apply to 386DOS.

V86 Mode and the 386

The 386 CPU has three distinct execution modes: REAL, PROT, and V86. REAL
and PROT modes are largely compatible with the corresponding modes of an 286.
V86 modes is exactly the same as RING 3 PROT mode, with the following
differences:

o Memory Address Hierarchy
A 386 has three levels of memory addresses:
– Virtual (Intel refers to this as Logical)
This is either the selector:offset or segment:offset address used by unprivledged machine language code.
– Linear
This is the 32-bit address arrived at either via a GDT/LDT
selector lookup, or via the 8086-compatible (seg << 4 + offset).
– Physical
This is the 32-bit address arrived at by pushing a linear address
through the paging mechanism. This is the address that the CPU
sends out on the bus to select physical memory.

When in V86 mode, the CPU performs the 8086-compatible computation.

o I/O instructions are NOT IOPL-sensitive
Trapping of I/O is done using the IO Permission Map.

o All instructions which modify or expose the Interrupt Flag ARE IOPL-
sensitive.
This allows the OS to simulate the Interrupt Flag, if desired.

V86 IRETD Frame

When any interrupt, trap, exception, or fault occurs in V86 mode, the CPU
switches to PROT mode and switches to the TSS Ring 0 Stack and builds the
following stack frame:

[[code]]czoyNDA6XCIKICAgICAgICAgICAgKDApIChvbGQgR1MpCiAgICAgICAgICAgICgwKSAob2xkIEZTKQogICAgICAgICAgICAoMCkgKG97WyYqJl19bGQgRFMpCiAgICAgICAgICAgICgwKSAob2xkIEVTKQogICAgICAgICAgICAoMCkgKG9sZCBTUykKICAgICAgICAgICAgICAgKG9sZHtbJiomXX0gRVNQKQogICAgICAgICAgICAob2xkIEVGTEFHUykKICAgICAgICAgICAgKDApIChvbGQgQ1MpCiAgICAgICAgICAgICAgIChvbGQge1smKiZdfUVJUCkgJmx0Oy0gKFNTOlNQKQpcIjt7WyYqJl19[[/code]]

CPU Mode Determination

A new implementation of the WHATMODE macro was written in order to distinguish
between the three CPU modes: REAL, PROT, and V86. REAL mode is indicated by
a 0 PE bit in CR0 (a.k.a. MSW on a 286). If the PE bit is 1, then the mode
may be either PROT or V86. These two modes may be distinguished by attempting
to change the IOPL bits in the FLAGS word. At Ring 0 in PROT mode (the only
place WHATMODE is used), the IOPL may be changed. In V86 mode, IOPL cannot
be changed. So, we change IOPL and then check to see if it changed. If so,
PROT mode, else V86 mode.

CPU Mode Switching

The 286DOS kernel relies extensively on switching inbetween REAL and PROT.
This functionality is provided by the RealMode and ProtMode routines.
In 386DOS, RealMode is no longer needed. As soon as we switch to PROT mode
during SysInit, the CPU only uses PROT and V86 modes.

Two new routines, ProtToV86 and V86ToProt, that are analogous to RealMode and
ProtMode. ProtToV86 is quite straightforward. We build a V86 IRETD frame
on the stack with the VM bit set in the EFLAGS image. We set the SS:SP
image to be equivalent to the stack just above the V86 IRETD frame, and
set the CS:IP image to instruction following an IRETD. Then, we issue the
IRETD and the CPU continues processing following the IRETD and in V86 mode.

V86ToProt is a bit trickier. The only way to get out of V86 mode is to
trap or fault or issue a software interrupt. We chose to use a software
interrupt, 30h, which we call the V86 Services interrupt. The INT 30h entry
in the IDT is a ring 3 interrupt gate, so issuing an INT 30 from V86 mode
causes a V86 IRETD frame to be built on the TSS Ring 0 stack and control
transfers to the INT 30h vector. The handler verifies that the INT 30h
was issued by the V86ToProt routine (checks CS:IP on the stack). If not,
the interrupt is reflected back to the requesting 3xBox (See Interrupt
Reflection). If it was V86ToProt, we clean off the stack frame and return to
the caller. NOTE: V86 Services is also used for completing the 386 LOADALL
used by PhysToVirt to map “high” memory in “REAL” mode.

Stack Switching

In order to maintain the 286DOS mode switch and stack switch semantics
when V86 mode is used, we have a new stack (the V86 Stack) in the 3xBox PTDA.

286DOS Modes and Stacks

The RealMode and ProtMode procedures in 286DOS are the only ways to switch
the CPU execution mode. These routines both maintain SS:SP, allowing
RealMode and ProtMode to be reentrant. The TSS Ring 0 stack is always the
current TCB stack in the current PTDA. The only other stacks in the system
are the Interrupt Stack and user stack(s).

386DOS Modes and Stacks

In 386DOS, any interrupt or exception while in V86 mode causes a switch to
PROT mode and the TSS Ring 0 Stack. So we have a new way to mode switch with
an incompatible stack semantic. We had to fix this mode switch to make it
compatible with 286DOS.

Observation

In V86 mode, the current stack must not be the TSS Ring 0 Stack. The CPU
only leaves V86 mode via an interrupt/exception, which causes a stack switch
to the TSS Ring 0 Stack. If the current stack was the same as the TSS Ring 0
Stack, then the stack might get corrupted. In 286DOS, the Ring 0 Stack is
the PTDA. Since we run on this stack in V86 mode, we need a new Ring 0 stack
when a 3xBox is running.

Approach

1) When a PMBox is running, the TSS Ring 0 Stack is a PTDA TCB stack.
+ This is consistent with the 286DOS model.

2) When a 3xBox is running, the TSS Ring 0 Stack is the “V86 Stack”.
+ The V86 Stack is allocated in the 3xBox PTDA.
+ If the cause of the mode switch can be handled without enabling
interrupts (e.g., interrupt reflection, IN/OUT trapping), we stay
on the V86 stack.
+ Otherwise, copy the V86 IRETD frame to the previous stack and
switch back to the previous stack.

Details

1) Leaving V86 mode
a. V86ToProt (analog of ProtMode)
+ Issue special V86ToProt software interrupt. If the interrupt
gate is DPL=3 (and it must be a 386 Interrupt Gate), then the 386
switches to Ring 0 (and the TSS Ring 0 stack) and transfers
control to the handler.
+ To ensure that 3xBox apps don’t use this feature, the interrupt
handler checks that CS=DosGroup and IP is in the correct range.
If not, then the interrupt is reflected (see below).
+ To make V86ToProt compatible with ProtMode, the interrupt handler
switches to the old stack (we get SS:ESP from TSS Ring 0 stack,
which is where we are running).
+ Finally, V86ToProt restores saved registers and flags from the
stack and returns to caller.

b. Software interrupt
+ GP-Fault handler reflects to 3xBox IVT handler in V86 mode.
o Add IRET frame on old stack, taking IP, CS, FLAGS from
TSS Ring 0 Stack.
o Look up handler in 3xBox IVT.
o Edit TSS Ring 0 Stack EIP and CS to point to IVT handler.
o IRETD
+ IVT interrupt handler IRET uses IRET frame we built on old stack.

c. Hardware interrupt
+ To make this operation compatible with 286Dos, the interrupt
handler copies the V86 stack from the TSS Ring 0 stack to
the old stack, then switches stacks to the newly modified old
stack. This allows the Interupt Manager to do an IRETD to
get back to the correct mode.

d. Exception
+ Remain on V86 stack, process exception, and IRETD.

2) Entering V86 mode
a. ProtToV86
+ Build V86 IRETD frame on current stack and IRETD.
b. LinToVirtDM_HANDLE
+ Execute 386 LOADALL with VM bit set in EFLAGS image in loadall
buffer.

Interrupt Management

All software interrupts, hardware interrupts, and CPU traps and exceptions
are vectored through a common IDT, regardless of whether the CPU is in PROT
or V86 mode.

NOTE: Background 3xBoxes get no hardware interrupts. In the commercial 386DOS,
this restriction can be relaxed so that interrupts, other than for the
keyboard and mouse (since those are implicitly for the foreground box),
can be given to background 3xBoxes.

Passing Hardware Interrupts to the Foreground 3xBox

In the interrupt manager:

IF a 3xBox is foreground -AND-
the current mapped 3xBox is background
THEN
MapIn foreground 3xBox;
Dispatch interrupt;

And to make things more interesting, from the later version of FOOTBALL, oddly enough version 4:

OS/2 FOOTBALL Boot Disk (v4.41.00)

This disk contained an updated version of OS/2 FOOTBALL Boot Disk (v4.41.00). It was built in December 1987, using final OS/2 1.0 sources merged with assorted FOOTBALL changes, and although it was originally assigned version number 1.3, this version of OS/2 would ultimately become 2.0.

It crashes on an 80286, jumping to invalid code immediately after performing a processor check. On an 80386, the following version banner is displayed:

[[code]]czoxNzU6XCJPcGVyYXRpbmcgU3lzdGVtLzIgIFZlcnNpb24gMS4zMAooQykgQ29weXJpZ2h0IE1pY3Jvc29mdCBDb3JwLiAxOTgxLCB7WyYqJl19MTk4NywgMTk4OC4KKEMpIENvcHlyaWdodCBJQk0gQ29ycC4gMTk4MSwgMTk4Ny4gQWxsIHJpZ2h0cyByZXNlcnZlZC4KCkludGVybntbJiomXX1hbCByZXZpc2lvbiA0LjQxLjAwLCAxMi8wMi84NwpcIjt7WyYqJl19[[/code]]

The numbering of revisions must have been, um, revised, because despite the lower revision (4.41.00 vs. 7.68.17), it is newer than the 7.68.17 prototype. This is confirmed by the boot message (12/02/87), the file dates (12-23-87) and the higher version number (1.3).

PCem

PCem v9

PCem v9

From the main page:

PCem v9 released. Changes from v8.1 :

  • New machines – IBM PCjr
  • New graphics cards – Diamond Stealth 3D 2000 (S3 ViRGE/325), S3 ViRGE/DX
  • New sound cards – Innovation SSI-2001 (using ReSID-FP)
  • CPU fixes – Windows NT now works, OS/2 2.0+ works better
  • Fixed issue with port 3DA when in blanking, DOS 6.2/V now works
  • Re-written PIT emulation
  • IRQs 8-15 now handled correctly, Civilization no longer hangs
  • Fixed vertical axis on Amstrad mouse
  • Serial fixes – fixes mouse issues on Win 3.x and OS/2
  • New Windows keyboard code – should work better with international keyboards
  • Changes to keyboard emulation – should fix stuck keys
  • Some CD-ROM fixes
  • Joystick emulation
  • Preliminary Linux port

Thanks to HalfMinute, SA1988 and Battler for contributions towards this release.

Very excellent!

OpenWatcom v2

I know what you are thinking, wouldn’t it be great if you could create MS-DOS executables directly from a Win64 desktop with no MS-DOS needed?

Well, I just found out about this unofficial Open Watcom v2 project that targets the usual suspects, allows you to compile from Win64!

Hello World!

Hello World!

Some of the features of this fork include:

  • New 2-phase build system, OW can be build by platform native C/C++ compiler or by itself
  • Code generator properly initialize pointers by DLL symbol addresses
  • DOS version of tools now support long file names (LFN) if appropriate LFN driver is loaded by DOS
  • OW is ported to 64-bit hosts (WIN64, Linux X64)
  • Librarian support X64 CPU object modules and libraries
  • RDOS 32-bit C run-time compact memory model libraries are fixed
  • Resource compiler and Resource editors support WIN64 executables
  • OW text editor is now self containing, it can be used as standalone tool without any requirements for any additional files or configuration
  • Broken C++ compiler pre-compiled header template support is fixed
  • Many C++ compiler crashes are fixed
  • Debugger has no length limit for any used environment variable

Binaries are available on sourceforge.

So how does it fare?  I thought I’d take the old Wolf4GW, and compile it with this toolset.  The first hurdle I hit was this fun feature:

  • The C++ compiler now treats warning W737, implicit conversion of pointers to integral types of same size, as an error.

Which is an integral part of wl_menu.cpp .  So this was somewhat problematic, until I just commented out that block, and while I was expecting no working keyboard, I’m able to play, and load/save games…. Even the boss key works.

Wolf4GW

Wolf4GW

So with the W737 taken care of, I have to say this thing compiles FAST.  Incredibly FAST.  If for some reason you have to build 16bit or 32bit anything, you should look at a 64bit tool chain, well assuming you have a 64bit computer by now.

If anyone want’s to build their own Wolf4GW with the newer OpenWatcom, my source drop is here.

PCem v8 released!

New features include:

  • New machines – SiS496/497, 430VX
  • WinChip emulation (including MMX emulation)
  • New graphics cards – S3 Trio64, Trident TGUI9440AGi, ATI VGA Edge-16, ATI VGA Charger, OAK OTI-067, ATI Mach64
  • New sound cards – Adlib Gold, Windows Sound System, SB AWE32
  • Improved GUS emulation
  • MPU-401 emulation (UART mode only) on SB16 and AWE32
  • Fixed DMA bug, floppy drives work properly in Windows 3.x
  • Fixed bug in FXAM – fixes Wolf 3D, Dogz, some other stuff as well
  • Other FPU fixes
  • Fixed serial bugs, mouse no longer disappears in Windows 9x hardware detection
  • Major reorganisation of CPU emulation
  • Direct3D output mode
  • Fullscreen mode
  • Various internal changes

pretty cool!

You can find the source code, binaries, and some ROMs on Tom’s Page.  I’ve got to say I really like PCem, it gives the full (slow and painful, like the real thing) retro PC experience!

Virtual Floppy Drive – Part III – Fun with HxC

(note this is a guest post from Tenox)

As promised in a post about Floppy Disk Emulators, here is a review of HxC Floppy Disk Emulator. I ordered it from Lotharek via eBay. Initially stuck in Polish post made it just before the weekend! This made my Christmas gift as I had a lot of fun playing with it. The unit comes with two front panel stickers, one grey and one black to match your equipment type. Quite nice touch. I choose grey as most of my units are of this color. I have to say the LCD screen makes a modern touch to an old 286 machine!

hxc286

286 machine with HxC installed in 3.5″ floppy bay.

Initially I have stumbled upon a lot of issues. Floppy disks are not easy as it seems. No wonder I had so much trouble with the real ones. I spent a lot of time experimenting with ID jumpers and correct BIOS settings. The unit only worked on ID3A but I can probably attribute it to a weird machine. Then I had problems converting my raw images to HFE format. The main project developer helped me a lot on their forums.

HxC Software. The latest version includes Track Analyzer!

HxC Software used to load and convert disk images. The latest beta version includes a Track Analyzer!

Once I got a grip how to do it semi correctly I was able to torture the machine with bunch of operating systems it has never seen before.  Let’s go directly to the screenshots!

 

QNX 2 worked just fine!

QNX 2 worked just fine!

Minix 2.0 also loaded without problems.

Minix 2.0 also loaded without problems.

So did Xenix 2.3

So did SCO Xenix 2.3

Xenix 2.3 boot complete.

SCO Xenix 2.3 boot complete.

Microsoft Xenix also saw daylight.

Microsoft Xenix also briefly saw daylight.

Xenix switched to CGA mode and died.

MS Xenix switched to CGA mode and died.

OS/2 1.3 did boot but my machine did not have enough memory to continue.

Guess which operating system is this?

Coherent 3.10 boots correctly as well.

Coherent 3.10 boots correctly as well.

PC/IX booted to Stand Alone Shell. I don't know what to do next.

PC/IX booted to Stand Alone Shell.

ELKS

ELKS

VenturCom Venix/x86

VenturCom VENIX/86

os2-2

I guess 640 KB is NOT enough for everybody.

 

This pretty much concludes operating systems for 286. If you have more let me know! I will try 386/486 operating systems in a separate post.

So how does HxC works for an end user? You store floppy disk images in a special format called HFE as files on an SD card. HFE files can be made by a virtual floppy disk emulator + rawrite, reading and imaging in an existing floppy, or converting existing floppy images. The list of supported disk images is quite impressive. The conversion however sometimes fails. It detects a wrong format and you have to change file extension or it completely screws things up making 64 “sides” to a floppy disk. Most if not all these have been fixed in the latest beta version of software, but you need to know about it.

When you insert the SD card to the emulator it will read the file list and allow you to switch between different floppy drives on the fly. Interestingly you can mix and match different floppy disk types on the same SD card. So you can have bunch of 3.5″ or 5.25″ disk in different files. Each HFE file contains specific settings for the emulator including the floppy interface type. The operating systems I’ve tried above ranged from 360k, 720k, 1.2MB and 1.44MB images stored on the same SD card. However changing floppy disk type in the BIOS was necessary for the images of different format to load correctly.

One extremely interesting feature is a host control software, that let’s you manage the floppy disks from inside the machine where HxC is attached. Sort of like VMware tools. The software is available for Atari, Amiga and Amstrad CPC. Unfortunately not for PC so I could not test at this time.

Because of the pain with formats, errors in conversions and confusion about some settings I can only give it 8 out of 10 for ease of use. So let’s conclude:

  • Packaging: excellent
  • Quality of hardware: excellent, LCD panel with menu is invaluable!
  • Software: OK with improving tendency in the beta version
  • User manual: OK but could be better
  • Compatibility: excellent! (see above)
  • Ease of use: excellent once you get grip on things
  • Value for money: excellent!
  • Total: very very good!

If you have a large collection of floppy disk images or you maintain a bunch of old machines that rely on floppy disks to work – get HxC quickly. It may save your life.

Updates: Venix/86 and ELKS, Tried OS/2 V1.0 and 640 KB RAM was not enough to boot.

Still missing: Microport SYSV/AT

Other floppy disk emulators.

Review of Gotek emulator.

 

Everyone mentioned this yesterday…

275,000 transistors of awesomeness!

275,000 transistors of awesomeness!

Kind of interesting is that Linux has finally dropped support for the 80386 microprocessor.

The 386 is perhaps one of the top ten things that has changed our world, along with 4.3BSD .

No, really!

The 386 microprocessor was the first CPU by Intel that was single sourced.  This means that Intel, and only Intel would fabricate the 386 processor.  Before this time, Intel had licensed their processors to other companies (Siemens, AMD, Harris, IBM etc) So that if there was some kind of production issue at Intel other companies could manufacture 8086,80186s and 80286s.  However this all changed with the 386, as Intel stopped renewing these agreements with other companies (IBM had a license that included the 386, although they were slow in making their own), so now Intel was in charge of its destiny.

The 386 brought three major changes onto the then champion processor the 286.  The first being a 32bit processor where it could handle larger data sizes than the 16bit 286 & 8086.  The 386 also included a larger memory model, the so called “flat mode” where it could directly address 4GB of combined code+data, while the 286 could address 1GB it was limited to 64kb segments.  Lastly the 386 introduced hardware virtualization, the “v86” mode where the 386 could emulate multiple 8086 processors, allowing people to have multiple ‘virtual machines’ on the desktop.

At the time the only consumer grade 32bit processor was the hybrid 32/16 68000 from Motorola.  The 68000 could work with 32bit data, but it was restricted to a 16bit data bus, and only could address 24bits of RAM (16 megabytes).  The 68000 however did not include any kind of memory management unit (MMU) making things like porting UNIX improbable (The SUN-1 workstation included a custom MMU).  Because of the open nature of the IBM PC, clone manufacturers were able to leapfrog IBM, and release 386 based machines before IBM got around to releasing the PS/2 model 80.  It was this that effectively brought 32bit computing to the masses with the Compaq Deskpro.

Compaq's 386 Deskpro

Compaq’s 386 Deskpro

The 8086 processor could address 1MB of RAM, with its 20bit address bus.  However to preserve some compatibility with the 8080 processor it was decided that the 8086 (and 8088) CPUs would work with 64kb segments.  This became a massive headache for years as you could not easily contain more than 64kb of data at a time as you would exceed a segment.  Compiler vendors made some workarounds via the large & huge memory models, but porting a program from a 32bit minicomputer (VAX) would prove difficult if it addressed large amounts of memory, and would require a rewrite.  The 286 increased the addressable memory to 16MB, and included a limited MMU, which enabled an address space of 1GB.  However the 286 was flawed in that again the 286 could only work in 64kb segments, and in order to work with large amounts of memory, the processor had to be shifted to protected mode.  However in protected mode, you couldn’t (easily) switch back to real mode.  This needlessly delayed the adoption of protected mode environments, as you would then lose access to the sizable, and growing, library of MS-DOS programs.  Although workarounds were in place for things like OS/2 and DOS Extenders, they were hacks and couldn’t fix the fundamental 64kb issue.  The 386 built upon the 286’s foundation and included a flat memory model where it could address all 4GB of addressable memory in a single segment.  This meant that you could now use massive amounts of data on a consumer grade machine.

For a while the only 32bit environments were Xenix and MS-DOS via DOS Extenders this proved to be a huge liability and effectively stagnated the industry for a long while.  The 286 was a massive determent.  Making things worse was IBMs insistence that the new OS/2 be able to run on the 286, while Microsoft wanted to create OS/2 to run on the 386, and ignore the IBM AT all together. Basically the 286 was created with the assumption that the 8086 wouldn’t be anywhere near as popular as it was.

With the ability to address large amounts of RAM programs only seen on minicomputers and mainframes were finding their way to the microcomputer such as AutoCAD, Oracle, Links 386 Pro, and of course many in house programs where departments now wouldn’t have to pay to run on then ‘big’ minicomputers.  Combined with the 386’s MMU it was also possible to use more memory than was available in the computer, also known as virtual memory.  The 386 made this transparent to the program, only the 32bit environment needed to handle the swapping.

Finally the last big feature of the 386 was v86 mode.  V86 mode in short is a hardware virtualization platform where the 386 can emulate multiple 8086 processors in hardware.  Each virtual machine can get its own isolated memory space, virtual hardware.  Effectively 8086 programs (such as MS-DOS) can run unaltered inside of v86 mode, with the added benefit of being able to run more than one at a time. Windows/386 lead the charge into this new world of virtual machines for the end user.  Before this point, the only wide scale virtual machine environment was the IBM 370 mainframe which could also create virtual mainframes within itself allowing groups to share a single mainframe, but run incompatible software platforms all at the same time.

Thanks to its capabilities the 386 also brought UNIX to the end user.  First with Xenix, then Microport SYSV, and with the removal of AT&T code BSD was able to be released on the 386 via 386 BSD (and later BSDi’s BSD/OS).  During this timeframe the research OS, Minix was extended by Bruce Evans to be able to use some of the 386’s features which then gave rise to Linux.

Thanks to cheap commodity based 32bit computers, and the GNU projects development tools (binutils, gcc, bash) people could then finally realize GNU’s dream of bringing a free and open UNIX like operating system to the masses.

Needless to say, a lot has changed since 1991, and Linux now moving beyond the 386 processor is no surprise.  The rapid adoption of 64bit computing via AMDs extensions, and the new forthcoming 64bit ARM processors do signal the eventuality that one day Linux will even drop support for 32bit processors… Although I wouldn’t expect that for another 20 years.  Even Intel has ceased manufacturing the 386 processor in 2007.

So it is now time to say good bye to the 386 processor.  At the same time thanks to full software emulation, you will never truly be dead. And as always you can check out Linux’s early versions.

Running OS/2 1.x on VirtualBOX Intel vs AMD

Well I know this is a limited topic, and my testing is anything but .. thorough.

But for some strange reason I’ve been trying to run OS/2 1.1 under VirtualBOX on Windows, and OS/2 crashes in under a minute all the freaking time.  It really is quite annoying.  Now I wonder if it is because my Windows PC has an 8 core AMD Processor?

Now when I run VirtualBOX (all the same latest version) under OS X, Intel it works fine!

OS/2 1.1 under VirtalBOX Mono EGA mode

Now what I don’t get is that under OS X with Intel Xeon CPUs I’ve been running for over an hour now, without issue!

As for settings, remember to add a floppy controller, remove the IDE CDROM, and remove the sound & networking!  I’m using 8MB of ram, but the glorious 80286 could go up to 16MB of RAM… Even though its virtual address space was 1GB!

I don’t know if anyone has any real insight into this whole AMD vs Intel thing, but from this super minimal testing it seems to me the Intel CPU is the way to go.

Also I don’t know why OS/2 decided to go with some greenscreen EGA.. It is kind of neat in a throwback kind of way, but nonetheless very odd.  I’d have preferred colour EGA but I guess you can’t win them all.