Apparently talking about DOS Extenders is too hot for Twitter: AKA Phar Lap 386

I had a small twitter account, and I tried not to get dragged into anything that would just be basically wasting my time. Just stay focused and on topic. FINE. I just wanted to see if anyone ever saw it, if it was even worth the effort of doing WIP’s as I didn’t want to make it super annoying.

I logged on to post a fun update that I’d finally gotten a Phar Lap 386 version 4.1 app to do something halfway useful, the sairen AGI interpreter up and running in the most basic sense.

Talking about DOS Extenders is spammy and manipulation!

I don’t get what triggered it, but oh well there was a ‘have a review’ and yeah that was fine. Great. So I’m unlocked so I go ahead and post with the forbidden topic, as I’m clearly dumb, and forgetting that Twitter is for hate mobs & posting pictures of food, and cat pictures.

The Sairen AGI interpreter built with Watcom 386/7.0 & Phar Lap 386 4.1

So yes, that was a line too far, and now that’s it.

Now some of you may think, if you buy ‘the plan’ you’ll no doubt be exempt from the heavy hands of Twitter

3 squids a month

But I already was and had been for a while.

Your account is suspended

So that’s the end of that. I guess it’s all too confusing for a boomer like me.

Cancel me, cancel you

So needless to say I cancelled Twitter as well. Kind of sneaky they didn’t auto-cancel taking money.

So yeah, with that out of the way, let’s continue into DOS Extender land. I added just enough 386 magic, onto github: neozeed/sarien286. Yes I see now it really was a poorly named repo. Such is life.

There is 3 main things for porting old programs where they take care of all the logic, it’s going to be File I/O, Screen I/O, and timers. Luckily this time it was easier than I recalled.

Over on usenet (google groups link) Chris Giese shared this great summary on direct memory access from various methods:

/* 32-bit Watcom C with CauseWay DOS extender */
int main(void) {
char *screen = (char *)0xA0000;
initMode13();
*screen = 1;
return 0;
}

/* 32-bit Watcom C with DOS/4GW extender
(*** This code is untested ***) */
int main(void) {
char *screen = (char *)0xA0000;
initMode13();
*screen = 1;
return 0;
}

/* 32-bit Watcom C with PharLap DOS extender
(*** This code is untested ***) */
#include <dos.h> /* MK_FP() */
#define PHARLAP_CONVMEM_SEL 0x34
int main(void) {
char far *screen = (char far *)MK_FP(PHARLAP_CONVMEM_SEL, 0xA0000);
initMode13();
*screen = 1;
return 0;
}

/* 16-bit Watcom C (real mode) */
#include <dos.h> /* MK_FP() */
int main(void) {
char far *screen = (char far *)MK_FP(0xA000, 0);
initMode13();
*screen = 1;
return 0;
}

It is missing the Phar Lap 286 method:

/* Get PM pointer to text screen */
  DosMapRealSeg(0xb800,4000,&rseg);
  textptr=MAKEP(rseg,0);

But it’s very useful to have around as documentation is scarce.

Which brings me to this (again?)

Phar Lap 386|Dos-Extender 4.1

Years ago, I had managed to score a documentation set, and a CD-ROM with a burnt installed copy of the extender. I didn’t know if it was complete, but of course these things are so incredibly rare I jumped on the chance to get it!

2011!

Unfortunately, I didn’t feel right breaking the books apart, and scanning them, then add in some bad life choices on my part, and I ended up losing the books. Fast forward *years* later and Foone uploaded a document set on archive.org. GREAT! As far as I can tell the only difference in what I had is that I’ve got a different serial number. Thankfully I was smart enough to at lest email myself a copy of the CD-ROM contents! And this whole thing did inspire me to gut and upload the Phar Lap TNT 6.0 that I had also managed to acquire.

Although unlocking the video RAM wasn’t too bad, once I knew what to do, the other thing is to hook the clock for a timer. ISR’s are always hell, but at least this is a very simple one:

void (__interrupt __far *prev_int_irq0)();
void __interrupt __far timer_rtn();
int clock_ticks;
#define IRQ0 0x08
void main()
  {
   clock_ticks=0;
   //get prior IRQ routine
   prev_int_irq0 = _dos_getvect( IRQ0 );
   //hook in new protected mode ISR
   _dos_setvect( IRQ0, timer_rtn );

/* do something interesting */
   //restore prior ISR
   _dos_setvect( IRQ0, prev_int_irq0 );
  }

void __interrupt __far timer_rtn()
  {
    ++clock_ticks;
    //call prior ISR
    _chain_intr( prev_int_irq0 );
  }

The methodology is almost always the same, as always, it’s the particular incantation.

So yeah, it’s super simple, but the 8086/80286 calling down to DOS/BIOS from protected mode via the int86 just had to be changed to int386, and some of the register structs being redefined. I’m not sure why but the video/isr code compiled with version 7 of Watcom, but crashes. I think its more drift in the headers, as the findfirst/findnext/assert calls are lacking from Watcom 7, so I just cheated and linked with Watcom 10. This led to another strange thing where the stdio _iob structure was undefined. In Watcom 10 it became __iob, so I just updated the 7 headers, and that actually worked. I had to include some of the findfirst/next structures into the fileglob.c file but it now builds and links fine.

Another thing to do differently when using Watcom 7, is that it doesn’t include a linker, rather you need to use 386LINK. Generating the response file, as there is so many objects didn’t turn out too hard once I realized that by default everything is treated as an object.

Another fun thing is that you can tell the linker to use the program ‘stub386.exe’ so that it will run ‘run386’ on it’s own, making your program feel more standalone. From the documentation:

386 | LINK has the ability to bind the stub loader program, STUB386.EXE, to 
the front of an application .EXP file. The resulting .EXE file can be run by 
typing the file name, just like a real mode DOS program. The stub loader 
program searches the execution PATH for RUN386.EXE (the 

386 | DOS-Extender executable) and loads it; 386 | DOS-Extender then loads 
the application .EXP file following the stub loader in the bound .EXE file. 


To autobind STUB386.EXE to an application .EXP file and create a bound 
executable, specify STUB386.EXE as one of the input object files on the 
command line.

So that means I can just use the following as my linker response file.

agi.obj,agi_v2.obj,agi_v3.obj,checks.obj,cli.obj,console.obj,cycle.obj
daudio.obj,fileglob.obj,font.obj,getopt.obj,getopt1.obj,global.obj
graphics.obj,id.obj,inv.obj,keyboard.obj,logic.obj,lzw.obj,main.obj
menu.obj,motion.obj,pharcga3.obj,objects.obj,op_cmd.obj,op_dbg.obj
op_test.obj,patches.obj,path.obj,picture.obj,rand.obj,savegame.obj
silent.obj,sound.obj,sprite.obj,text.obj,view.obj
words.obj,picview.obj stub386.exe
-exe 386.exe
-lib \wat10\lib386\dos\clib3s.lib \wat10\lib386\math387s.lib
-lib \wat10\lib386\dos\emu387.lib

It really was that simple. I have to say it’s almost shocking how well this went.

So, this brings me back, full circle to where it started, me getting banned for posting this:

32bit!

I thought it was exciting!

For anyone who feels like trying it, I prepped a 5 1/4″ floppy disk image.

running on 86box, 386DX-40 CGA graphics

One interesting observation is that the 386 extender is actually smaller than the 286 one. And being able to compile with full optimisations it is significantly faster.

16bit on the left, 32bit on the right.

I ran both the prior 16bit protected mode version (on the left), and 32bit version (on the right), on the same IBM PS/2 80386DX 16Mhz machine. You can see how the 32bit version is significantly faster!.

I really should profile the code, and have it load all the resources into RAM, it does seem to be loading and unloading stuff, which considering were in protected mode, we should use all ram, or push the VMM386 subsystem to page, and not do direct file swapping, like it’s the 1970s.

Phar Lap’s 286/DOS-Extender: why nobody used it for games

Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should.

-Ian Malcolm

Ever since I got my first 286 board way back in the early 90’s (1990? 1991?) I have been intrigued by the whole protected mode of operation. Unfortunately, in the era the required tools were way out of my reach, and of course were not available at retail. But now I live in the future where I have all the parts! Let’s look at the needed parts

I have to once more again thank my patrons, and people tolerating the google ads as it made all the difference in being able to buy all this stuff. And now is as good a time as any other to put it all together.

I stumbled upon this repo on sourceforge, Sarien. It included a Turbo C++ port, which is pretty exciting! So, this became my goal, get Sarien running on Phar Lap 286.

Installing Microsoft C 6.0a

Installing Microsoft C requires you to pick and choose both hosting, targeting environments, along with what the preferred libraries are. In the business we call this foreshadowing as this can be such a giant PITA. At least virtual machines are fast, plentiful, and cheap. In addition I had been using MS-DOS player to host the tools on Windows 11. This of course proved weird later.

The first step was getting it running on MS-DOS using Microsoft C 6.0a. This was actually pretty easy, the hard part was working out the makefile, as some files don’t compile with optimisations. And overall, the project doesn’t seem to work with /Ox at all. I haven’t spent enough time mixing and matching settings to find what actually doesn’t work, but I’m in a hurry, and /Os seems to work just fine.

In no time I had both the CGA & VGA drivers up and running and verified working on my PS/2. Great!

Now comes the fun, getting it ready to run on Pharlap.

The magic!

Phar Lap’s 286|DOS-Extender is pure magic. A DOS extender is a special program that can load a protected mode program into memory on a 286 or better computer and run it. At it’s heart, it can proxy MS-DOS functionality from protected mode to real mode, allowing you to use a lot of methodology and code from traditional real mode code. Phar Lap, goes beyond that by providing a pseudo OS/2 1.2 environment on MS-DOS, including advanced features like DLL’s, and being able to use ALL the RAM in your computer. Of course on the 286 there is a massive caveat:

The 286 has no built-in function for switching from protected mode to real mode. This makes programs that rely a LOT on MS-DOS potentially very slow. You can absolutely feel the difference between the real mode and the protected mode version of Sarien.

Phar Lap does include a test program, swtest which can benchmark the switching methods, so let’s run it and get some scores.

Switch code version = 1.14
BIOS signature: BA66CC86
BIOS date: 02/13/87

Machine ID = 0, A20 method = PS2, Reset method = Standard
Starting test for Switch Mode 3 (SLOW) ... Test complete.
Avg switch time (usecs): To prot = 34, To real = 101, Total = 135
Min switch time (usecs): To prot = 32, To real = 98, Total = 130
Max switch time (usecs): To prot = 35, To real = 103, Total = 138

Machine ID = 0, A20 method = PS2, Reset method = Standard
Starting test for Switch Mode 2 (AT) ... Test complete.
Avg switch time (usecs): To prot = 34, To real = 86, Total = 120
Min switch time (usecs): To prot = 33, To real = 83, Total = 116
Max switch time (usecs): To prot = 36, To real = 88, Total = 124

Machine ID = 0, A20 method = PS2, Reset method = Standard
Starting test for Switch Mode 1 (SURE) ... Test complete.
Avg switch time (usecs): To prot = 34, To real = 70, Total = 104
Min switch time (usecs): To prot = 32, To real = 68, Total = 100
Max switch time (usecs): To prot = 35, To real = 72, Total = 107

For those of you wondering what the timing is like on a 386, here is my 16Mhz PS/2 Model 80 board (now with fully 32bit memory)

Switch code version = 1.14
BIOS signature: 039D2DB4
BIOS date: 03/30/87

Machine ID = 0, A20 method = PS2, Reset method = Standard
Starting test for Switch Mode 5 (386) ... Test complete.
Avg switch time (usecs): To prot = 31, To real = 22, Total = 53
Min switch time (usecs): To prot = 30, To real = 20, Total = 50
Max switch time (usecs): To prot = 32, To real = 23, Total = 55

I’m honestly surprised the 286 switches from protected back to real so quickly! Although as you can see from the 386 timings it’s significantly faster than the 286.

Here is a quick video, real mode on the left, protected mode on the right. Yes I need to get a VGA capture card. Sorry.

Real mode on the left, Protected on the right. Running on the 386

Being a DOS extender it does have built in functions for things like hooking interrupts like this:

    /* install our new timer tick routine */
    DosSetPassToProtVec(IRQ0, (PIHANDLER)new_prot_timer_tick,
        &old_prot_timer_tick, &old_real_timer_tick);

Unlike some kind of OS/2 method which would involve creating a thread and or timers.

Setting video modes via the video BIOS is also supported, using the built in int86 style calls:

    memset(&r,0x0,sizeof(r));
    r.h.ah = 0;
    r.h.al = 3;
    int86(0x10, &r, &r);

Using pointers into things like video ram do require ‘asking for permission’ but it’s not too involved:

    int rseg;
  /* Get PM pointer to text screen */
    DosMapRealSeg(0xb800,4000,&rseg);
    textptr=MAKEP(rseg,0);

with the segment mapped, and a pointer to the segment, and now I can read/write directly into video RAM!

  /* save text screen */
    memcpy(textbuf,textptr,4000);

Just like that!

I’m not sure what I screwed up on the VGA graphics, as it doesn’t work correctly, but oddly enough CGA does work.

And now this is where everything goes off the rails.

Sairen running on Qemu & DOSbox

It ran fine on emulation. So all excited I fired up the PS/2 and….

General protection fault

This lead me to more fun in how on earth to debug this. Of course Phar Lap 286 version 2.5 requires me to have Microsoft C/C++ 7.0. I shamelessly downloaded a disk set from pcjs.org. You actually need to install it, to copy out the files required:

  • 28/05/1991 05:37 pm 47,216 CFIG286.EXE
  • 26/11/1991 11:19 am 13,531 GORUN286.EXE
  • 19/03/1992 04:00 am 42,720 shw0.dll
  • 19/03/1992 04:00 am 105,039 eew0cxx.dll
  • 19/03/1992 04:00 am 410,112 cvw4.exe
  • 19/03/1992 04:00 am 91,118 eew0can.dll
  • 19/03/1992 04:00 am 74,400 emw0w0.dll
  • 03/08/1992 09:34 pm 2,649 INT33.DLL
  • 03/08/1992 09:40 pm 2,718 MSG.DLL
  • 03/08/1992 09:40 pm 1,702 NAMPIPES.DLL
  • 03/08/1992 09:42 pm 2,073 NLS.DLL
  • 03/08/1992 09:43 pm 5,184 PTRACE.DLL
  • 03/08/1992 09:45 pm 2,320 SESMGR.DLL
  • 03/08/1992 09:50 pm 1,508 WIN87EM.DLL
  • 05/08/1992 12:04 am 3,100 KEYBOARD.DLL
  • 05/08/1992 06:33 pm 270 TOOLHELP.DLL
  • 14/08/1992 07:38 pm 7,891 KERNEL.DLL
  • 14/08/1992 09:40 pm 14,545 USER.DLL
  • 09/09/1992 10:59 pm 209,922 RUN286.EXE
  • 09/09/1992 10:59 pm 229,046 RUN286D.EXE
  • 14/09/1992 11:01 pm 14,024 TLW0LOC.DLL
  • 17/09/1992 07:26 pm 34,152 CVP7.EXE

While CVP7 does come with Phar Lap, you have to run it via run286. As you may have noticed there is a mixture of OS/2 and Windows DLL’s in here, as at this point CodeView was a Windows protected mode debugger. The divorce was in full swing, and Microsoft C/C++ 7.0 had amputated the majority of OS/2 support. I’m sure all this is in the manuals, however all I have is disk images. There was no C 6.0a supported hosted debugger. Maybe it’s in the v1/v2 of Phar Lap 286, but I only have 2.5. There is version 3 files on the internet but I wanted to stick to 2.5.

Exception #13

And this is all I got. Yes, I did recompile with ‘/Od /Zi’ along with using cvpack on the executable. Yes, after copying the source to the PS/2 I was able to see the source line mapping, but it immediately jumps to assembly and GP Faults. All this is fine, but IT RUNS UNDER EMULATION.

What is going on?!

I asked around on discord, and found someone willing to test on their 286. It also crashed. I tried VMware and .. it crashed too! So did 86box! Ok now we’re going somewhere!

Since I had been using MS-DOS player to run the tools, I had an issue with the linker in C 6.0a crashing, so I tried the one from C/C++ 7. It also didn’t work. I tried the one from Visual C++ 1.5. It also failed. Almost giving up on the entire thing, since I had copied the source code to the PS/2, I tried something really silly, I compiled it using the /qc or QuickC flag. I wasn’t too worried about sizes as again I’m going to run in protected mode. It took some 20-30 minutes to compile, as 10Mhz machines are not the best for building software in this modern age. Much to my surprise it actually ran.

First run!

This was kind of shocking as I’m not sure what I screwed up to not get this to work, but it worked! I went ahead and changed the build to not use QuickC, but rebuild with /Os (Optimize for space). It took about an hour. And it too worked.

Phar Lap 286 running on OS/2 2.00 on VMware

Shockingly it runs! I’m not sure what on earth is up with the linking. I did find it easier to just rebuild on Qemu since it can easily map into my source directory and copy everything over and re-build very quickly.

Later I did try copying over compiled objects built using the MS-DOS Player, and linked them natively, and they ran fine.

What is it with the LINK?!

It all fits! Stacker rules!

One weird thing on 86box is my pre-built machine I was using has a 5 1/4″ 1.2Mb floppy for the A: drive. It’s too small to fit MS-DOS, the game data and Phar Lap 286 all on there. Although Stacker to the rescue and it fits!

It can save and even load those saves!

I removed a lot of Unix quality of life, to make it more MS-DOS dumping everything in the same directory so you can save & load games.

Assuming anyone is interested in this at all, I have the source up on github. I’ll follow up with some performance videos showing how much slower real vs protected mode is, along with some binaries/demos. A 5 1/4″ floppy disk image can be downloaded here for any suitable emulator.

A weird EBay interlude on the way to Extending DOS.

I’ve always been fascinated with DOS Extenders, as they are such an ingenious method of breaking the rules of an environment by cheating the system. The first one I, like many others I imagine was using was DOSX that is the heart of Windows 3.0 on the 286. An incredibly tiny program but it let Windows run in protected mode, unlocking the potential of the machine. Great!

But as an aspiring programmer things were a quite a bit different. While QuickC for Windows did give you Microsoft C 5 hosted inside of Windows, effectively making the $99 for Windows and $99 for QuickC for Windows the cheapest DOS Extender dev kit of the time, it was of course limited to the 286. The 386 stuff although being the genesis of the DOS Extender was far more expensive.

But then with the advent of EMX for OS/2 and DJGPP for MS-DOS, both of them included DOS Extenders, and even better they were gratis! But of course they were GCC focused, and me being a kid saw the incredible 1MB++ size of CC1.EXE was thinking it’s insanely bloated, and of course slow. I don’t think many people were using 80386sx-16’s but I was.

Then there was this incredible offer from Watcom, who’d just become an internet (yes on usenet!) darling for being the compiler used to port DooM from NeXT to MS-DOS and it was available to students for a whopping $99. Neat!

Watcom C/C++ 10.0 retail packaging

Being in collage this was great. Another big plus of Watcom is that it was able to host on MS-DOS, Windows NT, and OS/2. And target far more!

So much included in the box!

Back then there was such incredible platform diversity in the PC space. Servers could be NetWare, Unix, OS/2 and that new fangled and often delayed Windows NT. Watcom was uniquely positioned to support so many of them, all from the same compiler set.

And of course most famously was DOS/4GW included in the box!

Despite having this, I’d always wanted Phar Lap TNT, as it brought insane features of Windows NT to MS-DOS, like DLL’s, and threads! But it was expensive, and I couldn’t justify it.

And this is where the story gets weird as I was also looking for their 286 product, and I found a copy on Ebay, and even better I easily won!

I can’t get a higher resolution image as the auction has expired out. But take note of the thumbnail.

PBI

And this happened. I was all happy expecting it to arrive when out of the blue the order was cancelled and refunded. I contacted the seller as I was totally wanting to get this, and to see if there had been some screwup in shipping, and they had told me that they didn’t know either has they had been refunded the sale price+shipping. So there we both were, me without my 286 Extender, and the seller with no disks to try to sell back again. And then this happened:

Phar Lap 286 magically reappears!

The disks showed up again for sale. We were both dumbfounded, how did this happen? Somehow someone intercepted the sale, and refunded us both, and then is trying to sell it on their own? Interestingly they won’t ship it to me, almost as if they are trying to block me from it.

Sketchy as hell as they say they are reselling from 3rd parties. Is there some kind of hustle going on where someone at a combined overseas shipping centre grabs random items, they can issue a refund for both parties so we don’t care, and then use a proxy sales site to sell them again?

Interestingly they know the disks read fine, as I know that too as I’d asked the seller to image them for me incase anything happened in shipping. I just never imagined it’d have been intercepted and resold. Maybe it’s common place, but I’ve been using Ebay since 1998 or so and well it’s the first time I’d ever seen something like this. Naturally bringing it up with Ebay is a total waste of time.

I’ll have to continue this with a deeper look into Phar Lap 286|DOS-Extender 2.5 as this is already far too much of a diversion from where I was going. But I thought I should point out this thing so buyer beware about the current listing.

**EDIT

Well seems I had the opposite effect I was looking for:

SOLD!

Free386 (386|DOS-Extender – RUN386 compatible)

I just found this late last night. The world can always use another DOS Extender, and here we go, out of Japan with Free386!

  • Version: 0.61
  • Date: 2016/12/28
  • Author: nabe@abk
  • Machine: PC/AT(DOS/V)
  • Machine in Japanese: FM-TOWNS, PC-9801/PC-9821
  • Compatible: MS-DOS and XMS and VCPI (with HIMEM.SYS and EMM386.EXE)
  • Language: NASM (Full assembly language)
  • Licence: PDS (Free386.com and Free386’s source files)

You can find it here: https://github.com/nabe-abk/free386

Poorly machine translated readme as follows:


From the futon, I thought i’d publish the “Free386” of dos-extender that I had made before to GitHub.

If you want to publish it anyway, NASM and alink also included together and if there is a DOS environment, i thought that anyone can assemble it is out of luck. I found a bug in alink when generating flat mode.exe/.com file. It’s around here that i started to go crazy in a lot of ways(laughs)

Patching alink was done on Linux. I then used TOWNS-gcc to generate alink.exp, but i used the MP header format that TOWNS-gcc generates. We found a bug that the EXP file cannot run on its own. If this is not corrected, it is not possible to distribute including the development environment because it does not usually have the EXP execution environment. When I checked, there was a bug in how to allocate memory, and when the memory capacity started to exceed 8MB, i was allocating memory space that does not exist in the back.

In fact, Free386 at the time was a lot of files that didn’t work properly, and i was worried because it became unstable, it was a mistake in the allocation of memory that is not. However, to examine this, i created a tool to dump memory maps and paging (i.e., it’s included), it was quite a bit of a hassle.

Now, when the memory allocation bug is fixed, almost all DOS generic EXP files and many TOWNS software now work. However, towns-OS’s biggest mystery system is the CoCo/NSD driver around the moss, and the software written in F-BASIC386 does not start. When you come this far, you want to move it.

So we start editing the CoCo/NSD driver. After a little research, I immediately found out the following.

  • CoCo.EXE resides in DOS memory (real memory).
  • NSDD resides in extended memory.

This means that CoCo is presumed to load nsd files into extended memory and manage that information. Now the question is how to get that management information. Is there information in coco memory that resides like SYSINIT? I thought.

For now, to check the area, Free386, i attached the ability to dump the register status before and after the int service was executed by hooking up the interrupt. We analyzed \hcopy\deldrv.exp, which has the ability to remove the specified NSD driver, as “we need to find the NSD driver and the structure seems simpler” in the mechanism.

------------------------------------------------------------------
Int = 0000_008E  CS:EIP = 000C:0000_1ADC   SS:ESP = 0014:0001_0B88
 DS = 0014        ES = 0060        FS = 0014        GS = 0014
EAX = 0000_C003  EBX = 0000_0001  ECX = 0000_0000  EDX = 0000_66EC
ESI = 0000_0246  EDI = 2074_6E00  EBP = 0001_0C48  FLG = 0000_0046
CR0 = 8000_0021  CR2 = 0000_0000  CR3 = 0002_9000    D0 S1 P1 C0  
------------------------------------------------------------------
*Ret:*
 DS = 0014        ES = 0014        FS = 0014        GS = 0014
EAX = 0000_0003  EBX = 0000_0010  ECX = 0000_0000  EDX = 0001_0C18
ESI = 0000_0246  EDI = 2074_6E00  EBP = 0001_0C48  FLG = 0000_0006
CR0 = 8000_0021  CR2 = 0000_0000  CR3 = 0002_9000    D0 S0 P1 C0  
------------------------------------------------------------------

Information like this comes out a lot in turn. If you look at the changes in coco’s residency and other changes in behavior, you can see that int 8eh/AX=Cx0x is a CoCo service. At the same time, log int 8eh and make a resident.com file (included) run386. I also looked at the behavior of the EXE and explored the commonalities of both of them, and i thought, “How would I design the mechanism if I were you?” We looked up coco services from the perspective of “**.

Then we traced to a service that provides driver resident information called int 8eh/AX=C103h. Using this information, the NSD driver in extended memory could be correctly pasted into memory and implemented on the selector. To verify, I ran deldrv.exp using Free386 and was able to uninstall the NSD driver correctly.

Great. End.

…… I wish I had solved it in that way.

TOWNS-OS is an OS of a mysterious structure, and even though there is a BIOS (TBIOS) of 32bit Native mode for graphicprocessing, some services such as timers use the BIOS of FM-R compatible 16-bit operation as it is. It has an incomprehensible structure to use it from the 32bit program side while managing resources, such as a 16-bit timer BIOS.

In terrible cases, each time the processing and interrupt of real-mode resources such as timers and keyboards, switch the CPU to real mode, if during those real-mode BIOS processing, interrupt the PROCESSING of the BIOS, such as FM sound source or VSYNC occurs, it seems to return to protected mode once.

NSD driver called forRBIOS (for Real BIOS) is the intermediary for this incomprehensible structure. Just as DOS-Extender acts as an intermediary for 32-bit programs and MS-DOS, it acts as a real-mode BIOS and a 32bit program intermediary.

In a RUN386 environment, when forRBIOS.NSD is built in, interrupt vectors such as int 8eh are rewritten so that the NSD driver gets the interrupt. **Where is this information? ** That was a mystery that was left behind. However, RUN386 is a . No matter how much the INT log is done until you run EXP, it doesn’t look like it. If you look at the memory of the coco that is resident, there is no information that seems to be it.

If you’re not going to initialize the resident NSD itself. I thought, i patched the entry of the resident forRBIOS, and when the service routine was called, i tried to use the rough business of falling into an infinite loop was bingo.

Finally, you can now run exp files generated by F-BASIC386 and so on. The analysis results are recorded in the doc. By the way, when you run a program that does not require forRBIOS (written in High-C, etc.), the whole process is slower than when you initialize forRBIOS. I really think this is the specs of TOWNS-OS (laughs)

This is the first time in more than a decade since the development was suspended in 2001, and the DOS-Extender, which is compatible with RUN386, was made.

What is with the price of retro Japanese software?

So I was lucky enough to get to Beep before it closed, and I picked out a couple of FM Towns titles (and a junker!), and I thought ‘Return to Zork’ would be a good title, something to compare the MacOS & MS-DOS versions against.

Although slightly faded, it does come in this nice box, which reminds me of the NEOGEO… which is probably an apt comparison.

The artwork has faded, although the CD-ROM inside was still sealed, never before opened. I picked this up for an eye watering Â¥3,480 but flipping the box over revealed the launch price of an astonishing Â¥12,800! I’m not sure what the exchange rate from 1994 was, but even at a generous 100:1 JPY to USD that’s half the price of the old multimedia kits which included the drive, sound card and so many came bundled with Return to Zork.

Another random title I grabbed was even more insane!

¥ 14,800 for Silent Möbius: Case: Titanic!

I need to get a RGB monitor & keyboard to see if this thing even works, meanwhile I fought with UNZ to get it running, and the mouse tracking is totally broken unless you change the DPI scaling, credit to this post in the UNZ ‘BBS’.

One thing is sure, the voice acting in the Japanese version is so terrible.

As people complain about ‘AAA’ games, and paying $60, just look at this! $134 USD for some cartoon boat game thing.. Although I’ve never heard of Silent Möbius or played it, I just saw it was available for the x68000 and PC-98. So I guess it’s one of those Lowest Common Denominator games.

One interesting thing about the FM TOWNS is that they have that ROM DOS with CD-ROM drivers, and their apparently blanket licensing for PharLap 386. Although while I was wasting time looking at cartoon rabbits, someone else scooped but the 386 BASIC kit. Darn.

But in the Return to Zork world, the ‘made.exe’ is in fact a Pharlap 386 EXP, meaning that it runs in 386 protected mode, so you don’t have to struggle with emm386, himem.sys and trying to get a ludercus 580-600kb of conventional memory. Seriously it was such a chore to get this running the manual has a big section on setting up a boot disk. It’s a shame they didn’t license a DOS extender for the US PC platform, although I can see why they chose that route on the FM Towns (and I believe PC98), as there is a RTZ9821 directory there which includes an EXP. Shame it was never relased state side as a patch, as it would have been a GREAT user change. Well that or a Win32 executable.

Links 386 Pro

Out on the course

Links 386 is one of those programs that is very easy to love to hate.  It was 1992, and PC’s were mostly being used for business, and high powered 32-bit machines were still insanely expensive.  And then Links 386 happened.  Before there was DooM, Links 386 was the ‘must have’ executive ball clacking device.  And the specs that you needed to run this game were really over the top.  At it’s heart was the Phar Lap 386 Dos extender, along with the virtual memory module.. Which most people would have to rely on.  Links 386 really needs over 8MB of RAM to run.  Yes, that is correct, in 1992 you were recommended to get 8MB (which should have been about $400-800 USD) So you can golf at your desk.  But as the name implies you also needed a 386 classed computer, although ideally you would have one of those new 486’s!  Links 386 also pushed the edge by wanting a VESA capable SVGA card that could use mode 101, 103, or 105.  Although the higher resolutions modes just ended up with logos everywhere, it really didn’t take enough advantage of the higher resolution modes.

Another interesting thing is not only does Links 386 have sound drivers (which means you need a sound card!) but it’ll do voice through the AdLib card.  Also it has a driver model, the WLZ, which I don’t know if they ever published or if people wrote additional sound drivers.

Links 386 installer

The installer is kind of cute, in that it’s flat shading is so old it’s now modern.  How’s that for crazy?

Installation is a snap, at only four diskettes.  They sold additional courses, and I only have one additional course, although oddly enough finding others online is pretty trivial.  However I had far less luck finding the program.  One nice tip to Infocom is that the courses include a score card, like the ones you would get on actual courses.  It really tied the package together.

Don’t copy that floppy!

Although for me, I really bought it for the manual.

Pebble Beach

And I have to admit it, Access Software did a great job.  Even all these years later, it looks great.  But no doubt scaling and placing all the textures is SLOW.  Incredibly slow.

Back in the 90’s I had a lowly support job, and I’d get flown all over the country to help out with issues, and it’d never fail that the regional director would have ‘issues at home’ and amazingly they’d always ask about running Links 386 Pro.  No doubt a lot of people upgraded machines, and got to brag to their buddies on how fast Links would now load.  Running at actual 386 speeds will take nearly a minute to render the screen between shots.

The DOS Extender was forever very touchy.  It took a bit of work to get around it’s issues, with the continuous conflicts with TSR’s, drivers, sound cards, video cards.. It was a nightmare of compatibility issues.  Not to mention that although Phar Lap 4.1 was DPMI compatible, it really didn’t play that nice with OS/2 or Windows.  Microsoft would later come to the rescue for this costed gamer market in the form of buying Links away from Access software, and putting out Microsoft Golf.  And much like SimCity, being able to run this under Windows make it immensely popular in the workplace, as all you needed to find were Windows drivers for your hardware, which vendors did actually support, unlike games.

It’s amazing how companies like Phar Lap, or Rational never did try to make an actual gaming platform for their extenders, leaving it all up to individuals.  My older self says that Microsoft’s rise to prominence in the 90’s was mostly due to their competitors incompetence, rather than their brilliance.

Although DOS Extenders like Phar Lap have been around since the introduction of the 80386, Links 386 Pro is the oldest one I know of.  If you like programs that try their best to bend the limits of what you can or should do, certainly check out Links 386 Pro!

Null DooM, GCC 1.39, GO32 and DPMI


phew.

DooM via DJGPP v1 GO32

Around the time of the x68000 port of DooM, I was cutting down the DooM source for a null/portable version.  I never could get it to actually run either using EMX or  DJGPP 1.03, as I couldn’t get it to link to save my life with a constant never ending battle of unresolved symbols. After a while I just used what I had towards the x68000 version and concentrated on getting it up and running, and just shelved the null/portable effort.

Later on I wanted to get it running again as part of messing with another cross compiler, as DooM isn’t a trivial application to port and verify correct operation. And in the process of trying to get the null version to build and run on Windows using TDM GCC, I wanted to make sure it at least kept compiling with GCC v1.x.

Once more again I was able to compile individual files but unable to link.  But this time, I just looked at the diffs for binutils, I thought it should be somewhat easy to get hosted on Windows.  Although versions may point to binutils 1.0, I had to use binutils-1.9.tar.gz even though the diffs are against Mar 24 1991, and the source for 1.9 is dated April 17 1991.

My first effort gave me a linker that would happily link, but go32 would either refuse to run the executable, or just crash.  I was going to give up again, but I found mention in another file that DJGPP actually uses the linker from G++, the C++ compiler which was a separate thing in the late ’80s and early’90’s.  This time it worked, and I could link a trivial hello world style application!

Now that I finally had a cross linker actually working, I didn’t want to compile under emulation, so looking at the other diffs, they didn’t look too extensive. I went ahead ,and took DJGPP v1.06 and patched up the compiler & assembler to get a full cross toolchain.  And in no time, I had a null version of DooM running on MS-DOS well at least tested on DOSBox.

This was fun, and all but I didn’t see any easy way to do fun things like hook interrupts so I could get the keyboard & clock like any good MS-DOS program.  DPMI greatly eased this kind of stuff, so looking at the DJGPP history, DJGPP v1 version 1.10 actually adds preliminary DPMI support!  And in the next version, DPMI was much more better supported, however the binary format had changed from a.out to COFF as part of the move to v1.11. I was able to take the memory, and DPMI portions from the final v1.12 libc, and manually build and run them against the v1.06 library / dev tools.

And much to my surprise, it actually worked!  At least having the wrong format didn’t have any effect on how GO32 worked for me.

So feeling lazy, I snagged some of the support code from Maraakate’s revamp of DooM, just to make sure of the timer code, and the keyboard code, and again verified that I can build with the keyboard & timer ISR and I’m able to play the v1.9 shareware & commercial levels fine.  I haven’t done a thing to clean up or update the DooM source itself against all the dozens of bugs and issues with Ultimate DooM, or other games like Chex Quest etc.

I’m sure 99% of people wouldn’t care but you can download it here:

Win32_DJGPPv1_DooM.7z
Download crossdjgppv1

Although I’m using DPMI to drive realtime events, if I looked further at the GO32 v1.06 environments I could either figure out how it operates it’s timer, or modify the extender directly to drive the PIC timer and keyboard as I need.  But overlooking that, the vintage 1991 software is more than capable of running DooM.

Wolfenstein 3D for DOS/4GW update

If you remember a while back, I had found the ‘missing link’ of Wolfenstein to Wolfenstein SDL, Wolf4GW.  Well Tobias has cleaned it up somewhat, and now it compiles on the latest builds of OpenWatcom 2.0c!

The first thing you’ll notice if you try to compile it, is that now it’s a single source file, that includes all the other modules.  And it compiles FAST, for me 1 second fast.

From the changes:

  • Compiles with OpenWatcom v2.
  • Keys (for Run, Shot…) are shown.
  • Hang with optimization is fixed.
  • Missing Spear of Destiny SignonScreen added.
  • Inter-procedural optimization (unity build).
  • External assembler routines re-implemented in C.
  • Better interrupt enablement /disablement.
  • Dead Code removed or #ifdefined.

So, if you want to Wolf3d, or SPOD, I’d check out Tobias’s Wolf4GW if you have a 32bit capable machine.  The maps load instantly, and it just feels all around much more smoother than the old 8086 code.

Porting Quake II to MS-DOS pt4

Bringing it all home for release day.

Bringing it all home for release day.

Since the last update we got some help in a few fields that have really fleshed out this ‘experimental’ port into a full fledged port.  First RayerR helped us with the fun of getting us onto the latest deployment of DJGPP, 2.05 (rc1).  It’s always nice to be in the latest available release.  Next in a passing comment, Ruslan Starodubov had mentioned that he had gotten a much older build of our QDOS to support the Intel HDA sound chipset via the  MPXPlay sound library.  I wrote to the author of MPXPlay, Pádár Attila asking for us to distribute his source in our project, and he granted permission.

So at this point things were looking good.  The only ‘feature’ that modern OS’s really held over us was the ability to dynamically load and unload game modules on the fly.  I had tried to use DLM, but it stripped the DPMI functionality out of the MS-DOS Extender making the port really useless.  I tried to build the newer DXE3 support but had no luck.  I suspect now my native tool chain was interfering with the build process. But Maraakate managed to get it to not only build, but to run!

Adding in DX3 support was relatively painless.  I first looked at DJGPP’s FAQ and downloaded the example code.  In the example code there was small helper functions to make unions and check the symbols.  If they didn’t exist a printf was spit out to alert you about it.  To resolve the issue you simply just add DXE_EXPORT to the other list of missing exports.

Compiling the game code was easy, again referring to the example I saw that basically they compiled it the same, but at link time you use DX3GEN and -U flag to ignore unresolved symbols.

The biggest head scratcher was the Sys_GetGameAPI failing to find GetGameAPI from the DX3.  After some piddling around I noticed that it listed GetGameAPI as _GetGameAPI inside the DX3 itself.  I added the underscore and it worked!

Other things that were relatively to easy to import was R1Q2’s HTTP downloading code.  Compiling CURL was kind of tricky because of the linking order, but thankfully neozeed figured it out quickly.

All of Yamagi’s Quake 2 updated game DLLs were all diff’d by hand using BeyondCompare to make sure I didn’t clash using some newer functions that weren’t available in DJGPP.  I also merged their Zaero code with their baseq2 code by comparing Zaeros code to the Quake 2 SDK, marking every thing that was changed.  The result is a really stable Zaero game code.  If you haven’t played Zaero check it out.  I think it’s a lot better than Rogue, but Xatrix is probably my favourite (even over stock Q2).

Other cool things I’m glad to get into the code was the GameSpy Browser.  It took me quite a bit of work to get it where it is, but it’s really nice to just be able to ping to a master server (a custom GameSpy emulator I wrote specifically for Q2DOS.  Source is not finalized yet, but will be available soon for those curious), pick a server and go!  All in DOS!

So here we are at the end of the journey.  Or at least safe enough for a 1.0 release.

To recap, we have:

* VGA
* SVGA (LFB modes only)
* Mouse
* Keyboard
* SoundBlaster and Gravis UltraSound Family
* CD-ROM music
* OGG music
* Networking (You need a packet driver)
* Loading/unloading game DLLs in DX3 format.
* Intel HDA support -hda
* Mouse wheel support with -mwheel

And I should add, that it works GREAT on my MSI Z87 motherboard.

You can download Quake II for MS-DOS on bitbucket.  And as always the source is available here.

Don’t forget you can always make bootable USB stick with DOS, or CD-ROMs.

Continued in Part 5!