Compiling Linux 0.11 using the December 1991 Windows NT Pre-release

Posted on August 2, 2024 by neozeed

It’s no secret that I do enjoy building silly “what if” things. And this is going to be one of the more impractical ones.

Building on previous work, where I had built GCC 1.40 using the OS/2 hosted Microsoft C compiler that shipped with this Pre-Release, and using MinGW to build Linux 0.11, it was time to combine the two, like chocolate & peanut butter!

Yes, it’s from 1981. I’m that old to remember this.

Getting NT ready

The first thing I wanted was to install the Pre-Release onto a HPFS disk. I’ve uploaded this over on archive.org (Windows NT December 1991 prepped for Qemu). I took the CD-ROM image, removed all the MIPS stuff, built a boot floppy, and setup the paths so that the floppy can boot onto the secondary hard disk to a ‘full’ version of NT. This lets me format the C: drive as HPFS, and then do a selective install of Windows NT to ensure that that the software tools (compiler) are installed.

I use a specially patched vintage QEMU build, qemu-0.14.0.7z which kind of makes it ‘easier’, along with the needed disk images in dec-1991-prepped.7z

qemu.exe -L pc-bios -m 64 -net none -hda nt1991.vmdk -hdb nt1991-cd.vmdk -fda boot.vfd -boot a

This will bring up the boot selection menu. The default option is fine, you can just hit enter.

NT will load up and you now have to login as the SYSTEM user. We need the advanced permissions to format the hard disk.

From the desktop we first format the C: drive as HPFS. I made icons for all this stuff to try to make it as easy as possible.

You’ll get asked to confirm you want to do this, and give the disk a creative name.

And with the disk formatted it’s time to start the setup process.

Who are you?

And what slick account do you want? It doesn’t matter tbh.

I’m going to do a custom install as the NIC’s aren’t supported, and even if they were it’s just NetBEUI anyways.

And select your hardware platform. NT basically only supports this config, so it doesn’t matter.

The default target drive is our C drive, which we had just formatted to HPFS.

Next, I unchecked everything only leaving the MS Tools

It’ll offer the samples & help files. I always install them as I eventually need examples of stuff to steal, and to learn that including <windows.h> won’t work right unless you manually define a -Di386 on the command line. I’m saving you this pain right now up front.

Files will copy, and on a modern machine this takes seconds.

And there we go!

And Windows NT is installed.

Yay.

I put in a ‘CAD’ feature in this Qemu hitting control+alt+d will send the familiar pattern, and after a few times NT will reboot. We are pretty much done with NT for the moment, but congrats you’ve installed the December 1991 Pre-release onto a HPFS disk for those sweet long long file names!

Going over the strategy:

I’ve already built GCC 1.40 for NT, so what is the rest of the stuff needed to build Linux? It’s a quick checklist but here goes, in no specific order:

~~GCC 1.40~~
bin86
binutils
~~gas 1.38~~
bison
unzip
zip

Luckily as part of building on Windows 10 using MinGW, I had fixed the weird file issues as MS-DOS/Windows NT/OS2 handle text/binary files, as we went through with how Github mangled MS-DOS 4.00.

The primary reason I wanted a working zip/unzip was to deal with long file names, and to auto convert text files. And this ended up being an incredible waste of time trying to get the ‘old’s code on the Info-Zip page.

Info-Zip’s old downloads. Version 5 only!

I’m sure like everything else, the old versions are removed as they probably suffer from some catastrophic security issue with overflows. The issue I ran into is that the version 5 stuff uses so many features of shipping NT, to even 2000 that it was going to be a LOT of work to get this far. The quicker & easier path as always turned out to be a time machine.

Thankfully, since I had made a copy of the UTZOO archives, I was able to fish out, both version 3.1 from the archives. Also known as “Portable UnZIP 3.1”, parts 1/2/3. I also found version 4.1 as well. And people wonder why you want to save these ‘huge’ data sets. If the lawyers could have their way, they would obliterate all history.

I spent a lot of time messing with Makefiles, as linking & object conversion on old NT is a big deal, and not the kind of thing you want to do more than once. Another big pain is that large files become delete only. I don’t know what the deal with notepad is, but I could remove text, but not change or add. I solved that by wrapping a number of things by including it in another file with some #define work to go around it. Needless to say, that sucked.

One thing that constantly threw issues is that this version of Windows doesn’t handle Unix style signals. I removed all the signal catch/throw stuff, and the binaries ran fine. Why on earth does ‘strip’ need signals is beyond me, but it runs fine without them!

Bringing it together.

From my “Build artifacts from Building Linux 0.11 on Windows NT build 239, December 1991” page, grab the two files, bin.zip & source0.zip.

On Windows I just unzip the bin.zip file and leave source.0.zip intact into a directly say something like temp. Then I can use a cool feature of Qemu where it can mount a directory as a read-only FAT disk. This saves a lot of time!

Running Qemu like this:

qemu.exe -L pc-bios -m 64 -net none -hda nt1991.vmdk -hdb fat:temp -fda boot.vfd

Will drop to the bootloader. Hit enter to login, and you’ll be at the desktop. Hit enter again, and open a command prompt.

By default, the Numlock is messing with the arrow keys (I think it’s mapping to the old 83 key keyboard no matter what?) Hit num-lock and your arrow keys should kind of work. It’s a great time saver.

copy the binaries to \bin & get ready to unzip

I copied the binaries & the ygcc.cmd file into the \bin directory, created a \proj directory and get ready to unzip all the source code. For some reason this version of unzip doesn’t understand the zip compression, so it’s just storing instead, much like TAR. It’s not that involved but unzip with the -d flag so it creates directories as needed.

This will let us keep long file names. HPFS is case insensitive, but it also preserves the case, so don’t worry about the names being all weird. It doesn’t matter.

One thing worth mentioning is that even though the C pre-processor does compile it just hangs when trying to run it. I’m not sure what is wrong exactly, but it’s just not worth fighting. Instead, I had the better idea, of using the Microsoft C compiler to pre-process the source. Apparently, this is how they originally built Windows NT, pre-processing on OS/2, then uploading the pre-processed files to a SUN workstation with the i860 compiler and downloading the objects to be converted & linked. Wow that must have been tedious!

I created a CMD file ‘ygcc.cmd’ to run the cl386 pre-processor, call CC1 & GAS and clean up afterwards.

cl386 -nologo /u /EP -I\include -D__GNUC__ -Dunix -Di386 -D__unix__ -D__i386__ -D__OPTIMIZE__ %2 > \tmp\xxx.cpp
\bin\cc1 -version -quiet -O -fstrength-reduce -fomit-frame-pointer -fcombine-regs -o /tmp/xxx.s /tmp/xxx.cpp
\bin\ax386 -v -o %1 /tmp/xxx.s
@del \tmp\xxx.s
@del \tmp\xxx.cpp

It’s not pretty but it works!

Building

Before you can build Linux, you need to create both a \tmp & \temp directory. Also the include files need to be copied to the \include directory to make the pre-processor happier.

I’ve tried to make this as simple as possible there is a ‘blind.cmd’ file which I built that’ll manually compile Linux. There is no error checking.

And saving everyone the excitement here is an animation of the build process

And there we go! All compiled!

From there it’s a matter of copying the Image file out of the VM, I used the boot floppy and 7zip’s ability to extract FAT images, and then boot up Qemu using the Image file as a ‘floppy’ as back in the day we used to rawrite these to floppy disks.

qemu.exe -L pc-bios -m 64 -net none -hda nt1991.vmdk -hdb fat:temp -fda boot\IMAGE -boot a

I don’t have a root filesystem, so the panic is expected, but yes, we just cross compiled Linux from Windows NT, circa 1991!

DooM, GCC & AI

Posted on May 30, 2024 by neozeed

One of the things that always annoyed me about DooM is the fixed point math. It relies on a 64bit data type, which many 32bit platform just lack. Namely the FixedMul & FixedDiv.

fixed_t FixedMul
( fixed_t a,
fixed_t b )
{
return ((long long) a * (long long) b) >> FRACBITS;
}

They are generally re-written into assembly, at least for the i386 getting around the whole 64bit on a 32bit platform.

FixedMul:	
	pushl %ebp
	movl %esp,%ebp
	movl 8(%ebp),%eax
	imull 12(%ebp)
	shrdl $16,%edx,%eax
	popl %ebp
	ret

FixedDiv2:
	pushl %ebp
	movl %esp,%ebp
	movl 8(%ebp),%eax
	cdq
	shldl $16,%eax,%edx
	sall	$16,%eax
	idivl	12(%ebp)
	popl %ebp
	ret

So that’d always been the ‘catch’ when porting Doom is that you either need a ‘long long’ data type, or the custom assembly or you basically are out of luck.

I know I’m a weird person, but I do like going backwards in terms of software, while most people want latest GCC 14 targeting old machines or some other hack, I prefer the opposite, trying to get the oldest stuff running on something new(er). In this case, it’s GCC 1.27.

While much of the old GCC history is lost, I did my best to collect as many versions as I could find here, along with doing patches in reverse to ‘reconstruct’ many old versions. The results are on archive.org. And what is significant from this, is the first version of GCC with i386 support appears in version 1.27.

From the internals-1 file we can find out that we all have William Schelter to thank for doing the bulk of the 386 port of GCC.

William Schelter did most of the work on the Intel 80386 support.
Internals-1 – gcc 1.27

With the first commit being on May 29th, 1988:

Sun May 29 00:20:23 1988 Richard Stallman (rms at sugar-bombs.ai.mit.edu)
...
	* tm-att386.h: New file.

GCC 1.25

The first GCC with i386 parts is 1.25, however it tends to emit the instruction movsbl, which GAS doesn’t like. Comparing the output to GCC 1.40 reveals this:

-	movsbl -12(%ebp),%ax
+	movsbw -12(%ebp),%ax

It’s trivial enough to change to a movsbw, but there are some other issues going on, and even the Infocom ’87 interpreter won’t fully build & run. The files input.c & print.c have to be built with a later version of GCC, in this case I used GCC 1.40.

However when using the old XenixNT build thing I did, I do get a runnable EXE!

I added the BSD targeting files from 1.27 allowing it to generate the needed underscores in the right places, as 1.25 by default only supports AT&T syntax. I guess the best way to illustrate it is to compile the compiler twice, once as the AT&T compiler, and the next being the BSD compiler, and compare their output:

cc1-att.exe hi.cpp -quiet -dumpbase hi.c -version -o hi-att.s
GNU C version 1.25 (80386, ATT syntax) compiled by GNU C version 4.8.1.

.text
.LC0:
        .byte 0x31,0x2e,0x32,0x35,0x0
.LC1:
        .byte 0x68,0x65,0x6c,0x6c,0x6f,0x20,0x66,0x72,0x6f,0x6d
        .byte 0x20,0x25,0x73,0xa,0x0
        .align 2
.globl main
main:
        pushl %ebp
        movl %esp,%ebp
        pushl $.LC0
        pushl $.LC1
        call printf
.L1:
        leave
        ret

And then looking at the BSD syntax:

cc1-bsd.exe hi.cpp -quiet -dumpbase hi.c -version -o hi-bsd.s
GNU C version 1.25 (80386, BSD syntax) compiled by GNU C version 4.8.1.

        .file   "hi.c"
.text
LC0:
        .byte 0x31,0x2e,0x32,0x35,0x0
LC1:
        .byte 0x68,0x65,0x6c,0x6c,0x6f,0x20,0x66,0x72,0x6f,0x6d
        .byte 0x20,0x25,0x73,0xa,0x0
        .align 1
.globl _main
_main:
        pushl %ebp
        movl %esp,%ebp
        pushl $LC0
        pushl $LC1
        call _printf
L1:
        leave
        ret

As you can see main: becomes _main:, just as labels (LC0/LC1) have a prepended, while in BSD they do not. There are no doubt countless other nuanced differences, but for the assembler & operating system to match you want these to align. Thankfully calling conventions are mostly the same per processor so you can add the underscores to the AT&T target and get something that’ll run, not only on DJGPP but also Win32, as MinGW32 uses BSD syntax at its heart!

C:\xdjgpp.v1\src>gcc hi-bsd.s -o hi.exe

C:\xdjgpp.v1\src>wsl file hi.exe
hi.exe: PE32 executable (console) Intel 80386, for MS Windows

C:\xdjgpp.v1\src>hi
hello from 1.25

Not that we really need to go all the way and have GCC 1.25 running on anything much, although at the same time it’s kind of fun!

Reaching out for help

The oldest & most robust GCC is 1.27, and I’d been able to use that to build DooM before, but the caveat is of course the fixed point math. I’d asked smarter people than I years ago about this problem, and basically was told to figure it out for myself. After all its ‘trivial’. But alas, I’m not smart. What I would do is build the fixed point math with GCC and try to re-work that into other compilers, although again for platforms without GCC or the target CPU lacking the 64bit data type is well.. fatal.

But AI, sadly for it, is compelled to help. So I just went ahead and asked and got a surprising result!

It’s very C++ like but it’s trivial enough to make it into old C.

Well on the one hand it does actually load up and play. But the controls go wild and I’m pulled into the intersection of these boxes, and unable to move. And as I rotate the floor and walls clip in and out. It’s very weird.

Not knowing anything about anything, I saw this ‘guard’ on the fixed division and tried to add that to the multiply:

	if ( (abs(a)>>14) >= abs(b))
		return (a^b)<0 ? MININT : MAXINT;

And I got something even weirder!

Not only that but the engine crashes! Not good.

After thinking about it on and off, asking for more help and going nowhere, I just gave up. It’s something beyond my skill, and apparently the AI as well. Until I had one of those moments in a dream where I had somehow told myself I bet the integers are not unsigned, and obviously fixed-point math needs all the bits, and it’s such a trivial fix, that even I should have figured it out.

I woke up at 4am and fired up the computer to see if it did anything. I was surprised to see that yes, in fact the integers were signed. I added the one key word, and recompiled using GCC 2.2:

And it RAN! I tried GCC 1.39, and too ran! I then made sure there was no assembly modules being called accidentally, and then re-built with GCC 1.27, and yeah, it runs!

Armed with a simple port of DooM to Win32, I went ahead and put in the fixed-point solution, and used Visual C++ 1.10 aka Microsoft C/C++ 8.0 to build DooM, and yes it works there too!

In the end I guarded it around a long long type, as I’m sure it’s much more faster, but for those without the types or any assembly skill, here is the solution:

/* Fixme. __USE_C_FIXED__ or something. */
fixed_t
FixedMul
        ( fixed_t a,
        fixed_t b )
{
#ifdef HAVE_LONG_LONG
    return ((long long) a * (long long) b) >> FRACBITS;
#else
    unsigned int ah,al,bh,bl,result;

    ah = (a >> FRACBITS);
    al = (a & (FRACUNIT-1));
    bh = (b >> FRACBITS);
    bl = (b & (FRACUNIT-1));

    /* Multiply the parts separately    */
    result = (ah * bh) << FRACBITS;     /* High*High    */
    result += ah * bl;                  /* High*Low     */
    result += al * bh;                  /* Low*High     */
    /* Low*Low part doesn't need to be calculated because it doesn't contribute to the result after shifting

    // Shift right by FRACBITS to get the fixed-point result                                            */
    result += (al * bl) >> FRACBITS;

    return (fixed_t)result;
#endif
}

/* */
/* FixedDiv, C version. */
/* */
fixed_t
FixedDiv2
        ( fixed_t a,
        fixed_t b )
{
#ifdef HAVE_LONG_LONG
        long long c;
        c = ((long long)a<<16) / ((long long)b);
        return (fixed_t) c;
#else
        double c;

        c = ((double)a) / ((double)b) * FRACUNIT;

        if (c >= 2147483648.0 || c < -2147483648.0)
                I_Error("FixedDiv: divide by zero");
        return (fixed_t) c;
#endif
}

fixed_t
FixedDiv
        ( fixed_t a,
        fixed_t b )
{
        if ( (abs(a)>>14) >= abs(b))
                return (a^b)<0 ? MININT : MAXINT;
        return FixedDiv2 (a,b);
}

I haven’t tested it on Big Endian machines yet. I’ve updated my terrible DooM engine port, along with Doom-New for DOS. Additionally, I’ve been able to confirm it works with Watcom 9-OpenWatcom 2. It might even work with 7 & 8 but I haven’t tried.

Thunking for fun & a lack of profit

Posted on February 19, 2024 by neozeed

So, with a renewed interest in OS/2 betas, I’d been getting stuff into the direction of doing some full screen video. I’d copied and pasted stuff before and gotten QuakeWorld running, and I was looking forward to this challenge. The whole thing hinges on the VIO calls in OS/2 like VioScrLock, VioGetPhysBuf, VioScrUnLock etc etc. I found a nifty sample program Q59837 which shows how to map into the MDA card’s text RAM and clear it.

It’s a 16bit program, but first I got it to run on EMX with just a few minor changes, like removing far pointers. Great. But I wanted to build it with my cl386 experiments and that went off the edge. First there are some very slick macros, and Microsoft C just can’t deal with them. Fine I’ll use GCC. Then I had to get emximpl working so I could build an import library for VIO calls. I exported the assembly from GCC, and mangled it enough to where I could link it with the old Microsoft linker, and things were looking good! I could clear the video buffer on OS/2 2.00 GA.

Now why was it working? What is a THUNK? Well it turns out in the early OS/2 2.0 development, they were going to cut loose all the funky text mode video, keyboard & mouse support and go all in on the graphical Presentation Manager.

Instead, they were going to leave that old stuff in the past, and 16bit only for keeping some backwards compatibility. And the only way a 32bit program can use those old 16bit API’s for video/keyboard/mouse (etc) is to call from 32bit mode into 16bit mode, then copy that data out of 16bit mode into 32bit mode. This round trip is called thunking, and well this sets up where it all goes wrong.

Then I tried one of the earlier PM looking betas 6.605, and quickly it crashed!

Well this was weird. Obviously, I wanted to display help

This ended up being a long winded way of saying that there is missing calls from DOSCALL1.DLL. Looking through all the EMX thunking code, I came to the low level assembly, that actually implemented the thunking.

EXTRN   DosFlatToSel:PROC
EXTRN   DosSelToFlat:PROC

After looking at the doscalls import library, sure enough they just don’t exist. I did the most unspeakable thing and looked at the online help for guidance:

So it turns out that in the early beta phase, there was no support for any of the 16bit IO from 32bit mode. There was no thunking at all. You were actually expected to use Presentation Manager.

YUCK

For anyone crazy enough to care, I uploaded this onto github Q59837-mono

It did work on the GA however so I guess I’m still on track there.

Porting GCC to 32bit OS/2

Posted on February 10, 2024 by neozeed

I know what you are going to think, that it was already done, and it was called EMX. Or was it GCC/2? Well sure but what if you are not running the GA (General availability) version of OS/2. For example, years ago I had managed to get Citrix Multiuser 2.0, and it’s not at the GA level. All that is available is some ancient beta version of Microsoft C 5.2 from 1989?!

A little while back I had worked on getting GCC to build and run on the FPU enabled versions of Windows NT from 1991. I had mentioned that it turns out thanks to the Xenix assembler, that GCC had been basically available the entire time Windows NT had been available, but lamented that since the OS/2 compiler is 16/32bit, the 5.2 compiler couldn’t handle compiling GCC without blowing it’s heap. 16bit issues in a 64bit world.

However after doing some research on all the early cl386 compilers I could get my hands on, including the Windows NT Pre-release ones, I’d noticed that if I built CC1.EXE (the actual compiler) first for Win32, then rebuilt those object files with the December NT Pre-release compiler, that some versions of LINK386 from the OS/2 2.1 DDK would actually link with them. And sure enough it worked!

I have to admit I was pretty amazed, I had managed to ‘cross compile’ GCC using quite the tool chain.

First the compiler from the December NT Pre-release CD-ROM is shipped as a 16bit OS/2 compiler, but I’m using Windows 11. First I use the MS-DOS player with a quick fix from crazyc to allow Phar Lap 286|Dos Extender to run, which provides a basic enough OS/2 emulation to allow the compiler to run under ‘dos’. The linker on the DDK suffers the same fate as far as it also being 16bit. However the combination of MS-DOS player & Phar Lap gets stuff working! The only weird catch is that the 386 emulator causes strange floating point related crashes, while the 286 or 486 emulators work fine.

Now targeting OS/2 or running on OS/2 isn’t all that new, but building it from a Microsoft C compiler is. And now of course you’ll ask yourself, who cares? why is it interesting?

Well, the vast majority of the GCC ports to OS/2 don’t support the OMF object file binary standard, instead they used the much outdated a.out format, and rely on tools to convert the objects if needed. Additionally, they have DLL dependencies, and other startup issues with things needing to be setup. And of course they rely on a binary standard that is ‘GA’. *HOWEVER* by using a Microsoft compiler, I have OMF object files that the OS/2 built in system linker LINK386 can understand. So in plain English I can just relink the compiler and it’ll run on a new ‘version’ of unsupported OS/2.

I made a diskette image with my objects & a linker script and in a few moments I had it running!

The substantial thing here is that the binary format for OS/2 changed twice, and each release introduced changes that broke binary compatibility, in an effort to force people onto the new tools. So there is no way that the old ‘LE’ format would ever work. And you can see it’s running! In addition I could take the same object files, and copy them to my Citrix server, and likewise it was just a matter of linking, and it too now has GCC!

One annoying thing is that the LINK386 that ships with OS/2 2.00 GA doesn’t like the output of the Xenix assembler, so I built the a.out traditional assembler, and the emxomf tool to convert the a.out to OMF, and that worked well.

I still have much to mess with, including the pre-processor & main ‘gcc’ program. I have not built anything beyond a trivial program, so there is indeed much more work to be done before I can even try anything challenging. Some programs like emxomf have portions in the debug support that require the ‘long long’ type, which obviously Microsoft compilers from 1989-1991 don’t have, so I’ll have to re-build them with GCC.

Ive been putting my ports onto github (cl386-research) as it handles the rapid changes well enough. It’s a bit of a complex setup and it involves using a build system that I’ve put over on archive.org here: cl386-research-v2.

Not that I can imagine anyone wanting to try but I’ve uploaded some disks with the objects. Copy them to a hard drive, and run the ‘build.cmd’ command and it’ll link to a native freestanding executable.

I’ll explain it more with a post later, along with going over all the versions of cl386 I’ve acquired, over the years in more of a part 2: Targeting OS/2 with Visual Studio 2003!

So it turns out GCC could have been available on Windows NT the entire time!

Posted on January 8, 2024 by neozeed

This is going to be a bit convoluted but here goes.. GCC isn’t a monolithic compiler, instead it’s various parts are separate programs. This lets us tackle it one part at a time. And/Or bypass a lot of it until I want to tackle it.

I’m sure many people have explained this far better than I ever could but in C you write source files (obviously), the pre-processor reads those and ‘header’ files that describe interfaces to libraries, other objects, various macros and definitions (magical numbers) and the pre-processor will read those files, and do simple macro expansion and test insert/replacements to generate a single .i file at the end of it’s run.

The C compiler (cc1) now reads that single .i file and translates it into native assembly. This allows for ‘mid/high level’ aspects of C to be machine independent (portable) but now will be written into a very system dependant assembly file, the single .S file. One thing of note is that so far everything is text files. You can edit the assembly file as you would any document, or even further ‘process’ it if needed/wanted.

The assembler ax386 (GAS) will then read the single assembly file and write a a binary object file hi.OBJ. There typically isn’t all that much to be said about assemblers although fancier ones allow for really strong Macro capabilities like Microsoft MASM.

From here on, it’s all binary objects!

The linker then takes your object files, and links them together with other system objects and system libraries into an executable, in this case. Linkers can build all kinds of other things, but for now we’re just pretending its static C compilation like it’s the 1970’s.

At it’s heart GCC processes text files.

The first part in this insane experiment, is to build GCC 1.40 with Microsoft Visual C++ 1.0. Surprisingly it didn’t take an insane amount of messing with stuff, and I got an executable! But everything it compiled failed to assemble. Looking at this fragment, even if you don’t know i386 assembly you might spot the error:

main:
        pushl %ebp
        a b,c
        pushl %esi
        pushl %ebx

Yeah, it’s the “a b,c” part. Those are NOT valid i386 opcodes!

Just because it compiled didn’t mean it actually worked.

I used MinGW to build the same source, same Makefile, and I got a working executable. Annoyed I started compiling random files with Microsoft C, and finally found the file that broke it all, it turned out to be insn-output.c needing to be compiled with the “/D__STDC__” flags. A quick modification of the Makefile and now I have a working CC1!

Okay, great, it’s well known back in the early dangerous ages of the 1980’s/1990’s that everyone wasn’t running Linux, nor were binary distributions of GCC that far spread, rather I think to re-enforce the source was available it was expected that you’d use your system compiler. Systems like DJGPP/EMX take the path of binding a.out object files into something that MS-DOS can run via a dos extender, or the bind utility to allow you to run the a.out on OS/2. What I wan’t to do is verify that in fact Windows NT was a viable host for GCC back in the public pre-releases of 1991.

I’m sticking with the December build 239 version as it has working floating point. Something that GCC has intrinsic support of, and I don’t feel like trying to work out emulation.

The next step is to try to build it with the family mode-OS/2 version of the C compiler, which of course lead to the real issue of this 16bit hosted cross compiler:

        cl386 /u /Od /Ic:\MSVC32S\C386\INCLUDE /I. /Iconfig /c combine.c
Microsoft (R) Microsoft 386 C Compiler. Version 1.00.075
Copyright (c) Microsoft Corp 1984-1989. All rights reserved.

combine.c
combine.c(1734) : fatal error C1002: compiler is out of heap space in Pass 2
NMAKE : fatal error U1077: 'C:\WINDOWS\system32\cmd.exe' : return code '0x2'
Stop.

Very frustrating. I tried mixing and matching from Visual C++ 1.0 & this old compiler, and while it did compile, it doesn’t run. does it mean anything?!

GCC 1.40 compiled by Microsoft 386 C Compiler. Version 1.00.075

I should point out that this should be an expected working configuration as GCC does build on Xenix using the 32bit Microsoft C 5.1/386 compiler. Furthered again that Xenix and these 1991 versions of NT use the same 32bit OMF object format. And expanding on the Xenixnt experiment using the Xenix’ified GAS assembler with old Visual C++ includes & libraries to produce a possible retro-early port of GCC to NT, the next move is to bulid GAS on NT.

Xenix GAS 1.38 compiled by by Microsoft 386 C Compiler. Version 1.00.075

GAS gave me some weird issues with ctype.h where it runs fine with the one from Visual C++ 1.0 but the OS/2 & NT pre-release both fail. However the old Pre-release compiler cannot deal with the much newer ctype include file. So after much hammering I amputated whatever was bothering it, and it’s just enough to build & run. Great!

Going back to the phases, I used a simple hello world program:

void main() {
 printf("Hello World!\n");
}

While not being a good program, it doesn’t include stdio.h, nor does it return anything. It’s terrible. But in this case it allows me to be lazy and sidestep the pre-processor cpp.exe. This way I can just directly run it through cc1 and get my assembler file hi.S

Next I pass it to ax386 (GAS) and get the resulting object file hi.OBJ

And finally link it with link.exe in this case.

And with all the drama I’ve now compiled a simple hello world program on Windows NT.

If it were 1991, I would hollow out gcc.c so it doesn’t use signals or forks to invoke the needed phases, and of course build the pre-processor. In addition, libgcc needs to be compiled to allow for floating point operations to work correctly. None of which is impossible, although I’m not sure it’s all that needed as it isn’t 1991.

With a little bit more work, I got the floating point support to compile, which relies on both a working ‘native’ compiler, and a working GCC to compile the 2nd half. I usually use phoon, or Phases of the Moon, to test floating point, and as you can see, it’s working!

I’m not sure if there was a 32bit version of Microsoft C/386 available for Microsoft OS/2 2.00 betas. Also, I don’t know if the Microsoft link386 for OS/2 can also link Xenix 386 object files? Would it have been possible to bootstrap GCC/GAS on Microsoft OS/2 2.00? I really don’t know, and as of this writing no versions of the old Microsoft OS/2 2.00 betas have surfaced.

** update from the future, turns out that I found a way to convince the cl386 compilers from the NT Pre-Releases in 1991 to re-build an existing GCC that was built for NT. The catch is the linker, LINK386 of course, as the format was constantly changing. However the object files are fine, and I was able to just copy them over on diskette and re-link the compiler. It even ran. It’s not tested at all, so it turns out the 1989 compiler wasn’t good enough, but the 1991 was.

It’s interesting to me to see that even before GCC 2.6, that vintage versions from 1991 would compile and run directly on Windows NT.

I uploaded the source on github, along with some binaries.

Since people were asking for xMach binaries

Posted on July 11, 2023 by neozeed

Since binaries had been requested, along with the old elf cross compiler I thought I’d try that new fangled github binary releases.

This is just taken from old artifacts from the old Building OSkit & xMach adventures.

I had made a vmdk, MachUK22-lites.vmdk.7z as well, not sure if that helps anyone.

Fun with Windows ePDK NT 3.1 build 196 & Some Xenix fun!

Posted on June 1, 2023 by neozeed

I’m not sure if I covered the Windows NT 3.1 build 196 before. First the most obvious is that as of this moment it’s the earliest version of Windows NT available.

So let’s do some obligatory scratch of the surface. Like all the other 1991 pre-releases there really is just a text mode setup install script. Choosing the lesser amount of pain, I went with a MS-DOS hosted install. However, using MS-DOS 6.22 resulted in a broken dual boot system. But we live in the era of virtual machines, so it really doesn’t matter. I’m using Qemu 0.14-rc2, something that is ‘era correct’ for when the first avalanche broke on early Windows NT pre-releases. I’ve had issues with more modern versions of Qemu, and I felt that if we’re using vintage software may as well go in all the way.

The boot loader identifies itself as being 1990 vintage. Pretty sure it doesn’t mean anything, but we haven’t been blessed with the “blue screen” of ARC yet.

The login screen and desktop have a very strong Windows 3.1 beta feel to them. And that would land this where it was, Windows was such a big seller that Maritz had been trying to convince Gates & Balmer to ‘switch to the Windows horse’ in the spring/summer of 1990, culminating in Gate’s July decision to walk away from NT/OS2 and rebrand the new OS as Windows NT. Oddly enough it was Balmer who was in favour of OS/2 & IBM. (Showstopper 89-90)

At first glance the opening window isn’t all that interesting. It’s just very. Windows.

Rest assured Reversi, of course made the this Win32 cut. And it’s full of weird easter eggs, oddly enough in the OS/2 surviving bits.

type OS2LDR.DOS
OS2LDR 01.00.01
by KeithMo 01/08/91

On the Discord there had been a big discussion about early NT executable formats, and the whole COFF vs ECOFF vs PE/PEI. I had tried to hunt down the specific version of GCC I used ages to to build a so called Dec Alpha GCC cross compiler, but the short version is that it didn’t work as we don’t have any assembler/linker for anything GNU targets. There had been a cygwin port a n d a n OpenNT on Alpha, but all that is lost to the winds, minus what few scraps I had saved. I did try building some cross tools to elf hoping to just objcopy out the data and get linkable objects, but that didn’t work either.

So I though this was a perfect opportunity to take a look at this early pre-release version of NT, and although I do know that you have to convert your objects into something the ‘COFF’ linker will accept:

And I never really paid that much attention to the object files. I do know that you can link them with Link386 for OS/2, but the NT object files themselves report:

wsl file SIMPLE.OBJ
SIMPLE.OBJ: Intel 80386 COFF object file, not stripped, 4 sections, symbol offset=0x102, 20 symbols, created Thu Jun  1 14:13:50 2023, 1st section name ".text"

Well, now that is interesting. And of course the COFF thing reminded me of Xenix! And sure enough ages ago I had found the source to a modified version of GNU GAS that outputs COFF. Once more again this is an indication that all 386 roads in Microsoft really did originate with Xenix. It’s too bad there never was a Windows/386 on Xenix/386. What an incredible OS that would have been! There must be some incredible stories from the tool teams that worked on Microsoft C/386 along with other projects. Oddly enough they never get anywhere near as much exposure as Office or OS.

Now this is fun, but nothing takes in these ancient COFF objects, do they? I tried to run LINK 1.0 from Win32s SDK and surprisingly it didn’t complain about the object, rather, it auto converted it in memory:

Microsoft (R) 32-Bit Executable Linker Version 1.00
Copyright (C) Microsoft Corp 1992-93. All rights reserved.

SIMPLE.OBJ : warning LNK4016: unresolved external symbol "__chkstk"
LINK : warning LNK4016: unresolved external symbol "_mainCRTStartup"
SIMPLE.OBJ : warning LNK4016: unresolved external symbol "_printf"
SIMPLE.exe : error LNK1120: 3 unresolved externals

Does this mean that if I give it some libraries it will actually link?

LINK.EXE SIMPLE.OBJ /SUBSYSTEM:CONSOLE /MACHINE:i386 -entry:mainCRTStartup -out:simple.exe libc.lib kernel32.lib
Microsoft (R) 32-Bit Executable Linker Version 1.00
Copyright (C) Microsoft Corp 1992-93. All rights reserved.


C:\temp\nt196\x\dec\x>simple
Win32, it's happenin'!

This was. VERY unexpected.

So I had this crazy idea, what if the Xenix assembler could in fact build objects that are also compaible in this manner? I used the a.out GCC / Linux porting tools I had built so I could compile Linux on Windows NT using the vintage tools as a starting point. I guess I should also add that when people always say ‘use newer version of THING’ this is how you miss out on old stuff like this. If I had been obsessed with using modern tools and modern operating systems, I’d have missed out on this Xenix filled window.

I took the gcc driver & the cc1 compiler from 1.40 and the c pre-processor from 2.5.8 as it can understand C++ comments. First I manually compiled the ‘simple’ example to assembly:

gcc -v -nostdinc -I/xenixnt/h -S SIMPLE.c -O simple.S
gcc version 1.40
 cpp -nostdinc -v -I/xenixnt/h -undef -D__GNUC__ -Dunix -Di386 -D__unix__ -D__i386__ -D__OPTIMIZE__ SIMPLE.c C:/Users/jsteve/AppData/Local/Temp/cca2_048.cpp
GNU CPP version 2.5.8 (80386, BSD syntax)
#include "..." search starts here:
#include <...> search starts here:
 /xenixnt/h
End of search list.
 cc1 C:/Users/jsteve/AppData/Local/Temp/cca2_048.cpp -quiet -dumpbase SIMPLE.c -O -version -o SIMPLE.s
GNU C version 1.40 (80386, BSD syntax) compiled by GNU C version 5.1.0.
default target switches: -m80387
 cpp -nostdinc -v -I/xenixnt/h -undef -D__GNUC__ -$ -Dunix -Di386 -D__unix__ -D__i386__ -D__OPTIMIZE__ simple.S C:/Users/jsteve/AppData/Local/Temp/cca2_048.s
GNU CPP version 2.5.8 (80386, BSD syntax)
#include "..." search starts here:
#include <...> search starts here:
 /xenixnt/h
End of search list.

Which gave me the following assembly:

        .file   "SIMPLE.c"
gcc_compiled.:
.text
LC0:
        .ascii "Win32, it's happenin'!        .file   "SIMPLE.c"
gcc_compiled.:
.text
LC0:
.ascii "Win32, it's happenin'!\0"
.align 2
.globl _main
_main:
pushl %ebp
movl %esp,%ebp
pushl $LC0
call _printf
leave
ret
"
        .align 2
.globl _main
_main:
        pushl %ebp
        movl %esp,%ebp
        pushl $LC0
        call _printf
        leave
        ret

Now to assemble with the GAS Xenix assembler

C:\temp\nt196\files\MSTOOLS\SAMPLES\SIMPLE>ax386 SIMPLE.s -o SIMPLE.obj

C:\temp\nt196\files\MSTOOLS\SAMPLES\SIMPLE>wsl file SIMPLE.obj
SIMPLE.obj: 8086 relocatable (Microsoft), "SIMPLE.c", 1st record data length 10, 2nd record type 0x88, 2nd record data length 11

Not quite the same. But it does closer resemble the output from the OS/2 bound versions of the Pre-Rease compilers:

file EMPTY.OBJ
EMPTY.OBJ: 8086 relocatable (Microsoft), "empty.c", 1st record data length 9, 2nd record type 0x88, 2nd record data length 7

So will it link?!

C:\temp\nt196\files\MSTOOLS\SAMPLES\SIMPLE>LINK.EXE SIMPLE.OBJ /SUBSYSTEM:CONSOLE /MACHINE:i386 -entry:mainCRTStartup -out:simple.exe libc.lib kernel32.lib
Microsoft (R) 32-Bit Incremental Linker Version 2.50
Copyright (C) Microsoft Corp 1992-94. All rights reserved.

SIMPLE.OBJ : warning LNK4033: converting object format from OMF to COFF

C:\temp\nt196\files\MSTOOLS\SAMPLES\SIMPLE>simple
Win32, it's happenin'!

Well now this is interesting! LONG before MinGW, or the GCC port to Windows NT, it turns out that in fact GCC could target Windows NT the entire time!

So the next thing to do is something not as trivial, like phoon.

I setup some quick script to pre-process, compile, assemble and then try to link, but as this one uses floating point, disaster struck:

phoon.obj : error LNK2001: unresolved external symbol "___fixdfsi"
astro.obj : error LNK2001: unresolved external symbol "___fixdfsi"
phoon.exe : error LNK1120: 1 unresolved externals

Now ages ago while messgin with old GCC & DooM I also had weird math calls not working. In the end I ended up extracting them from libgcc builds, so I thought I’d try the libgcc built during the GCC 2.6.3 on NT adventure.

link /NODEFAULTLIB:libc.lib /NODEFAULTLIB:OLDNAMES.LIB -out:phoon.exe astro.obj date_p.obj phoon.obj -entry:mainCRTStartup libgcc1.lib LIBC.LIB KERNEL32.LIB
Microsoft (R) 32-Bit Incremental Linker Version 2.50
Copyright (C) Microsoft Corp 1992-94. All rights reserved.

And of course:

To try to make the steps make a little more sense, and to allow for some higher level of automation I made a Makefile:

CC=gcc
CC1=cc1
AS=ax386
CPP=cpp


CFLAGS= -O
CPPFLAGS= -lang-c-c++-comments -nostdinc -I/xenixnt/h

OBJ =   astro.obj \
date_p.obj \
phoon.obj

LIBS = libgcc1.lib LIBC.LIB KERNEL32.LIB

phoon.exe: $(OBJ)
        link -out:phoon.exe $(OBJ) -entry:mainCRTStartup $(LIBS)

%.obj: %.c
        $(CPP) $(CPPFLAGS) $< $*.i
        $(CC1) $*.i -quiet $(CFLAGS) -version -o $*.S
        $(AS) $*.S -o $*.obj


clean:
        del $(OBJ) *.i *.S phoon.exe

I’m sure there is better ways to do this, but it breaks the compile up to it’s individual parts:

Run the pre-processor to allow // in the comments, C++ hadn’t been the default thing back when GCC 1.40 was a thing. Also path it to the headers, in this case I’m using the ones from NT 196. Trying to link with the 196 libraries gave me this:

C:\xenixnt\demos\phoon>link /NODEFAULTLIB:LIBC.LIB /NODEFAULTLIB:OLDNAMES.LIB -out:phoon.exe astro.obj date_p.obj phoon.obj -entry:mainCRTStartup base.lib wincrt.lib ntdll.lib \xenixnt\lib\libgcc1.lib
Microsoft (R) 32-Bit Incremental Linker Version 2.50
Copyright (C) Microsoft Corp 1992-94. All rights reserved.

wincrt.lib(maincrt0.obj) : warning LNK4078: multiple ".data" sections found with different attributes (40000040)
astro.obj : error LNK2001: unresolved external symbol "_asin"
astro.obj : error LNK2001: unresolved external symbol "_atan"
astro.obj : error LNK2001: unresolved external symbol "_atan2"
phoon.obj : error LNK2001: unresolved external symbol "_cos"
astro.obj : error LNK2001: unresolved external symbol "_cos"
astro.obj : error LNK2001: unresolved external symbol "_floor"
astro.obj : error LNK2001: unresolved external symbol "_sin"
phoon.obj : error LNK2001: unresolved external symbol "_sqrt"
astro.obj : error LNK2001: unresolved external symbol "_sqrt"
astro.obj : error LNK2001: unresolved external symbol "_tan"
phoon.exe : error LNK1120: 8 unresolved externals

Which is not surprising as there is no FPU/Floating point math support in 196. I tried the December 1991 Pre-Release, but it failed for other reasons:

I did copy over BASE.DLL BASERTL.DLL CSR.DLL DBGDLL.DLL as it wanted, but despite the symbol being in the DLL it didn’t load.

So that’s why I’m using the libraries from the Win32s SDK.

Okay, so far now we have GCC 1.40 compiling to an old Xenix GAS assembler, and linking with Microsoft link from Visual C++ 1.0/2.0 era. The next step is to see if we can just link the objects under 196, and get a running EXE!

I have this tiny fibonacci example program, so with it compiled & assembled by GCC & GAS, I did the final link under 196, and YES it runs!

I then built the ’87 InfoTaskForce, Infocom interpreter, and it was just a simple link, and it’s running!

Possible things to do? GCC should be able to build itself, so it should be possible to build GCC and link that on 196 or December 1991, and get a native version of GCC on NT. The other possibility is to get newer versions of GCC (cc1 drop in replacements) to build for Xenix and / or OS/2. Obviously this Xenix linker is the gateway to older 386 Microsoft based products!

For those interested in such things, I’ve uploaded all of this to archive.org here: windows-nt-196-linking-and-running-gcc

39 years ago, the dawn of home 32bit computing.

Posted on January 22, 2023 by neozeed

Much like the ZX Spectrum the Sinclair QL was a machine largely unknown to me growing up in Canada, then moving to the Miami area as a teenager. While the ZX 80/81 were pioneers in low end home computers barely able to do anything the ZX Spectrum with it’s 80kb of RAM (48k usable, as half the 64kb was defective), the QL announced in the start of 1984 was announced to the world as a very serious business machine. No gaming around to be found here!

While the IBM PC had been released in 1981 with it’s 16bit Intel 8088 processor utilizing a much slower & cheaper 8bit bus, the QL went one step further utilizing the Motorola 68008, a hybrid 16bit processor with 32bit registers, also using an external 8bit bus. However, being always on the cheap sifde, the QL only offered a single expansion slot, unlike the IBM PC. Also it eschewed floppy disks in favour of it’s endless loop ‘micro drive’ cassettes. Every corner that could be cut was, and sadly the resulted in a machine that just wasn’t ready as one has to wonder if the word of the Macintosh launch the following week was out, and Clive knew that it was either announce it now, or be a meetoo going forward. For better or worse he launched.

On paper it sounds fantastic, 128kb of ram, 32bit capable processor, and 2 drives all for Â£399! The IBM PC was an eye watering Â£3,325 by comparison, while the similarly spec’d Macintosh was Â£2,698! Indeed the QL stood for Quantum Leap, as the jump from 8bit to 32bit home computing was going to be phenomenal.

The avid jogger, Clive taking his Quantum Leap.

But how could it all go so wrong? Within a year the price had been slashed to Â£199, and stores were said to be further marking them down to a mere Â£99 the year afterwards. How could a seemingly on par machine fail so badly? The 128k Macintosh also was limited to a paultry 128kb on it’s motherboard, while the more expensive, and expandable IBM PC/XT maxed out at infamous 640kb, and it supported up to two floppy drives, and 2 hard disks although the IBM AT would be announced later that year, and it could go well beyond 640Kb, but the lack of protected mode operating systems & software would hinder the platform for quite some time.

If the trades are to be believed it was a combination of announcing too early, and failing to deliver burnt people on the QL. Additionally the ZX Spectrum had been busy wining apps at the time (games), but Sinclair wanted so much to be a serious company, not the man who brought you jet-set “fucking” willy. Sound and video capabilities of the QL were no match for the Spectrum, just weren’t there, and also missing was the incredibly cheap European storage of choice the audio casette. Many people were also dismayed that the operating system was much larger than expected and it needed to occupy both internal ROM sockets, and the cartridge port. And of course, the microdrives themselves were seen as easy to corrupt, stretch and tear. Not the kind of thing someone in business wants to hear. The ironic thing about the QL was that in my opinion it was too cheap. The PC/XT offered plenty of expansion at the base price (albeit a high one), and Apple also quickly added a much more realistic 512kb model Macintosh. The QL never got a ‘big brother’, basically condemning it at launch as nothing more but a toy. Which is a shame.

The operating system, burnt into ROM feels kind of 8bit as it has a basic interpreter built in, and it’ll open several hard coded windows in which you are expected to interact with. However, it feels more like a minicomputer with input on the bottom, running lists on the left, and output on the right. Indeed, it can feel outright baffling. And certainly nothing like an 8bit machine, or like the later home 32bit machines like the Amiga, or Mac. Even the TOS based Atari ST felt more ready for the world with its GEM burned into ROM.

Building my dream system

Despite all of these downsides, I was still intrigued by the machine, and I have to admit I really love the look of it. When I’d first read Neuromancer around the time of the video game, and this is what I’d imagined a cyberdeck to look like. While I was wasting my youth with an 8bit machine I wanted to experience this seemingly parallel universe where affordable 32bit micros were a thing.

Since I’ve heard of the machine, I’ve been trying to get one. Surprisingly for such an unloved machine they are incredibly hard to find, and they do go for quite a bit of money. However, thanks to making contacts on the QL User’s forum, I had managed to get my hands on one, so I could start my journey. I sent it off to RudeDog Retros, luckily located across the bridge from where I’m staying and within a week. I was able to get back a working system. I also had managed to get a tetroid ram expansion/CF card addon as well for my QL bringing it up to 880kb of RAM, and an 8MB CF card, making the machine a top of the line experience. Although the card was given to me with known issues, for the most part it worked, except when it didn’t, and it was always the same, bad ram at the 128kb boundary. Which is a shame, having mass storage certainly gets around the microdrives, but 128kb of ram just isn’t enough when factoring in mass storage.

Much like other 68000 based machines, the Sinclair QL is no stranger to hardware modifications. I ordered a 512kb memory expansion unit (Sinclair QL 512KB Internal Memory Expansion from *der_englaender*) to fill in the 128k gap from the Tetroid card (plugged into the left). The red 68008 socket is a real pain to deal with, and it took an unreasonable amount of force to get the RAM expansion into the QL. No doubt nearly 40 year old sockets are just not that flexible. I had thought the board was in, but I was getting a buzzing black screen, it only took a bit of reassuring and swapping in another 68008 to verify the machine was fine, and more pressing to get it to seat into the socket.

Sinclair QL effectively with no CPU!

You can also spot the Hermes 2.20 co-processor upgrade to support 19,200 baud serial operations, along with the Minerva OS upgrade, and you can see the numerous RAM chips that had to get replaced to make the unit functional. With an appropriately upgraded system it can begin to feel like a real machine.

Thanks to the folks over at The Sinclair QL Forum, I was able to complete the upgrade!

With enough luck my machine now has reliable memory, mass storage, and faster communications with the outside world. Everything you’d want in a modern computer! I now have a capable machine to do the one thing I always worry about when doing cross compiling, actual hardware verification.

SIxteen/Thirtytwo into EIght dreams…

The 68000 was used by Stanford University in it’s project based motherboards, that gave way to the 68010 based SUN-1/SUN-2 based machines, where other companys also used the 68000 line of processors in their Unix based machines. While the QL with it’s cost conscious 68008 was not going to run a ‘real unix’, it was however capable of running real programs. The big AT&T compilers (PCC!) can target the processor, just as other new and upcoming compilers, even GCC, although even 880kb of ram is probably not enough for running GCC natively. But going back to 1985 this leaves room for something more restricted to mini-computers, Hack.

While Hack had been ported to 16bit machines like the IBM-PC, or sixteen/32bit machines like the Amiga, I was surprised to find that it had not appeared on the QL. For someone like me that first meant getting a cross compiler in place to target the QL. Thankfully xXorAa had done a lot of the hard work in xtc68, qdos-libc, and Dilwyn Jones had saved the GCC patches by Richard Zidlicky, Jonathan Hudson, Thierry Godefroy and Dave Walker. With a working cross compiler, time to get hacking!

From the mini-computer to the 32bit home micro-computer

Doing my thing I put together a simple cross compiler so that I could begin work. With enough RAM, the QL is in the surprising league of many a minicomputer of the early 1980’s. It’s incredible to think of what a missed opportunity this is. When I had decided to try to get Hack-1.03 up and running, I went for the Unix version, bypassing the probably more apt PC port, as despite Hack-1.03 being free enough to be still part of OpenBSD, PC Hack however has a more restrictive license. I know it’s weird.

Using a VT library that gives the QL, something akin to ANSI.SYS functionality and another library to set environment variables (yes QDOS doesn’t have either…) a simple basic program to setup the screen type and point Hack where to find it’s files, and we are suddenly off to the races. I didn’t have to restrict or cut anything down, it’s running the same code that effectively would run on a VAX-11/780 mini-computer, or a SUN-2 workstation. It’s crazy how this machine didn’t fill the home 32bit gap that took Microsoft/Intel quite a few years to fill.

For those into the javascript, you can download a disk image: hack.win here, and test drive it on ppe/xXorAa‘s emulator here sQLux – MIN198.rom, 4096K (qlforum.co.uk)

Another great program, COM, the 8080 CP/M emulator can also happily run on the QL, again with libvt, emulating a vt52 it opens up an entire ecosystem of software, much like it did on the Commodore-128. If it had been available perhaps it would have greatly helped out things for the platform as it languished.

While the QL was marred with it’s too early announcement/pre-orders, and terrible primary storage medium, and far too restrictive motherboard design, there was great potential in that tiny little machine. I’d like to have thought if I’d known about the QL, I’d have bought one, even though the 128kb is super restrictive, thanks to it’s processor it really was an incredible machine for 1984.

In the days of cheap arm machines, and who knows what the downstream effects of those will be, it feels like there was a much earlier missed window with the Sinclair QL.

When YYLEX shouldn’t be confused with yylex

Posted on November 13, 2022 by neozeed

While trying to build some old stuff I ran into this weird issue where YYLESX is undefined:

gcc -DHAVE_CONFIG_H -I. -I. -I../../include -I../.. -I../.. -I../../include -g -O2 -Wall -c cs_grammar.c
cs_grammar.y: In function â€˜cs_parseâ€™:
cs_grammar.y:1074:58: error: â€˜YYLEXâ€™ undeclared (first use in this function)
1074 | yychar = YYLEX;
| ^~~~~
cs_grammar.y:1074:58: note: each undeclared identifier is reported only once for each function it appears in
make[3]: *** [Makefile:334: cs_grammar.o] Error 1

Notice it’s all UPPERCASE, but you can find plenty on the lowercase issue where its not being linked correctly. And yeah turns out YYFLEX should define out toe yyflex

# ifndef YYLEX
#  define YYLEX		yylex()
# endif

Add that in the top of whatever source is complaining and you’re golden.

Really.

nonsensical benchmarks

Posted on December 1, 2021 by neozeed

So I was messing with quake1 & DJGPP/DOSBox. So yes that means this table is largely nonsense. My larger goal was to see if a strictly softfloat could run Quake1. The answer, is no.

However I got some weird answers from messing around with the flags & fps from a timedemo of demo1

FPS
67.7
113.4
130.1

131.9
101.3

73.0
71.7
31.1

44.6
32.7

CFLAGS
-O0 -m386 -m80387
-O2 -m486 -m80387
-O2 -m486 -m80387 -mhard-float -mno-soft-float -mieee-fp -mfp-ret-in-387
-O2 -m386 -m80387
-O2 -m386 -m80387 -funroll-loops -fomit-frame-pointer -fexpensive-optimizations
-O2 -m486
-O2
-O2 -msoft-float -m386 -funroll-loops -fomit-frame-pointer -fexpensive-optimizations
-O2 -msoft-float -m386
-O2 -msoft-float -m486

This needs to be a table! it’s unreadable!

So surprisingly -O2 -m386 -m80387 produced the fastest code using GCC 2.7.2.3. On DOSBox so yeah that means literally nothing. Rebuilding DOSBox with no floating support code gave a weird error about the pov being out of range.

Obviously the next thing to do is run this stuff natively.. .which means GCC 2.7.2.3 for NT. Oh this is going to be fun, but utterly pointless. Or maybe not.

I re-ran the tests using VMware. There is no audio drivers involved just plain MS-DOS. The red is DOS-Box while green is VMware for the graph with FPS being the measurement. Interesting how the numbers aren’t as varied like DOSBox, however the -m386 -m80387 proved the be the worst for VMware, while the 386 soft float was so incredibly slow on DOSBox but performs great on VMware. yay?

Virtually Fun

Fun with Virtualization

Category Archives: gcc