Built myself a 486

[wierd_w]

QEMM was never magic for me.  Every time I encountered it, it was causing some kind of strange edge case to happen.

Granted, I worked at a mom & pop repair place during that era, and so my sample is surely biased toward the negative. (people dont bring working systems in to be serviced....)

 

Instead, I got to be very good at manually prodding DOS into efficiently using the upper memory area, and had a list of go-to DOS drivers that were both very compact, AND very reliable/capable.

A copy of MSD to be able to peer into the memory map to see where things were loading, and how big they were, would let me do what Memmaker did, only more guided/fine controlled. 

 

The biggest thing, is to have a system with a BIOS that stays the hell out of the adapter rom region.  Many bioses, especially in the late pentium era, wanted to jam all kinds of crap in there, like realmod USB drivers, PXE bioses that would NEVER get used, etc. To effectively use the adapter rom region to provide UMBs, you need to keep stuff out of there so you can do the remapping.

 

[Keatah]

I enjoy the nostalgia I have with the old 486. Built it out decades ago, with the last bit being an XTIDE/CF interface. Maybe I'll through in a gotek.

 

Got tons of stuff in the mid-late 90's. Got a printer, scanner, a Snappy, a 4-way joystick adapter, 3rd hard disk with special IDE BIOS to go with it, 2nd parallel card, Zip Drive, some A/B switches, internal 14.4K modem, ergonomic keyboard, trackball/mouse, multiple gamepads and joysticks, extra custom proprietary Micronics branded memory card with 8MB (1MB SIMMS), parallel/serial buffer, and so much more miscellanea. Loaded the system up with DriveSpace, SmartDrive cache, a DDO, and other TSRs. VESA/sci-tech display doctor, all the necessary SB drivers, Guest.EXE for zipdrive, MSCDEX for CD-ROM, Network card and driver.. And more that I can't recall at this instant.

 

But all this can be overload. So much that I have thoughts about returning it to near-factory configuration, keeping only the SoundBlaster, 14.4 modem, and 2nd parallel card, as the only add-ons. Also removing DriveSpace, SmartDrive, and the DDO. The network card, and 2nd IDE card and 3rd HDD would go too.

 

Should I do any streamlining, I'd keep all the parts'n'stuff. And it would be based on nostalgia. I never got into PC networking (in earnest) till the Pentium II arrived. the 3rd HD was for Win95, more or less to try it out, never used it much. Disk compression was a big thing for me. So that's up in the air as to whether I remove it or not. Was near-magic!

 

I've imaged the current configuration, so it would be easypeasy to segue between different setups. All said and done - it was fun making everything work together.

Edited March 7, 2022 by Keatah

[sirlynxalot]

Awesome. Reminds me of a pentium 166 my family shared in the 90s on which I did a lot of dos gaming.  We had a gravis ultrasound so my nostalgia for dos game music is usually a little different than what the typical YouTube playlist has.

[Keatah]

I only had a few basic tools to help me optimize and maintain the 486 back then:

Microsoft Diagnostics

Check-It

Norton utilities 6 through 8

MEM /c /p

..and various reference books and memory map charts.

 

Not forgetting Scandisk. Everybody loves Scandisk! It even has its own brand of flash memory and usb sticks!

 

Today I value virtualization tools, vast storage that's easily searchable, and all the speed of modern hardware. Love how some of the tedious details are suddenly obfuscated and how multiple configurations are but clicks away.

 

Yet, all the stuff learned back then is what makes using DosBox, VirtualBox, and PCEM so easy. One just kinda knows what is and isn't possible. And what approach to take when trying to fix something. Growing up the hard way!

 

 

[NE146]

On 3/5/2022 at 1:13 AM, eightbit said:

 

For the people that say "just use dosbox", you have no idea at all. The satisfaction of getting everything to function was bliss. It was a few weeks in the making (mostly waiting for parts, testing, jumpers, resolving issues/conflicts, etc), flashing the Gotek and setting that up, removing the barrel battery and hacking a battery replacement, and the feeling after getting everything working perfectly is a great one. 

I always say it's odd to see a 486 as "desired" because in my mind, the computers I've used from my 486 in the 90's, and up to my current computer, were ALL the same thing basically.   i.e. It was all was just one continuous never-ending "getting improved gear and newer OS" over the years... but the same basic computer. Just faster!

 

Although I guess clearly it's mutated by this point, so I need to have a paradigm shift.  

Edited March 7, 2022 by NE146

[Keatah]

11 minutes ago, NE146 said:

I always say it's odd to see a 486 as "desired" because in my mind, the computers I've used from my 486 in the 90's, and up to my current computer, were ALL the same thing basically. i.e. It was all was just one continuous never-ending "getting improved gear and newer OS" over the years... but the same basic computer. Just faster!

I think it has to do with the 486 being a respectable jump in performance over what came before it. Bigger steps were taking place. And 486 DX2 machines had enough oomph to play console-like games and kick off the emulator scene, though the latter just barely.

 

Nostalgia and preferences for an architecture or point in time can be very personal.

 

For me it was having 50x speed of the Apple II, 125x the memory, and ungodly high resolution. Not forgetting the beautiful sounding SB16. There were possibilities!

 

Comparing against the 16-bit machines was similar. 8x faster than Amiga/ST, 10x the memory. Parts everywhere.
 

486 came out at a time just prior to the BigBox store explosion. Just as they were transitioning into a supermarket away from warehouses and specialty shops.

 

Then there was the clock-doubling, bus-decoupling. Today’s 5GHz entry/level machines would not have been possible otherwise. 
 

The 486 also represented increasing integration of features into the CPU. Cache and FPU were the first and famous examples.

 

it was a mix of both the state of the industry and technological achievements that lent fame to the 486. 
 

Conversely, that era saw too many busses. ISA, EISA, VLB, PCI, MCA, and others yet still. What a mess! 

 

But most important of all is we each have our memories of the good times the platform delivered. And they define the greatness that is 80486!

[zzip]

45 minutes ago, NE146 said:

I always say it's odd to see a 486 as "desired" because in my mind, the computers I've used from my 486 in the 90's, and up to my current computer, were ALL the same thing basically.   i.e. It was all was just one continuous never-ending "getting improved gear and newer OS" over the years... but the same basic computer. Just faster!

That's what the PC world became.   Nowadays you upgrade your PC, you get mostly a faster version of what you had--  mostly USB, same HD/SSD interfaces, usually Same GPU interface.   CPU socket probably different.   But everything else is now integrated on the motherboard.

 

But back in the 90s the PC world was a circus,  competing standards (ISA, EISA, VLB or PCI bus?  IDE or SCSI? / Serial or PS2 mouse?)  you needed a separate soundcard, separate IO card (for floppy, harddrive interfaces), there were more manufacturers in the game,  more CPU makers than just AMD and Intel,  probably a dozen videocard manufacturers, etc.

We didn't have the fancy BIOSes we have today, most configuration changes had to be done by changing jumpers on the motherboard.    It was also a time of transition from DOS and all its idiosyncrasies to Windows 95 which felt like a complete OS for once,  and not just a fancy app launcher bolted onto aging MS-DOS (even though under the hood it was still much like that)

 

It was also an exciting time,  Mom and Pop PC shops popping up all over town,  Computer Shopper magazines the size of phone books coming every month which was always fun to page through to see what the latest prices were (this was before the internet was mainstream, and you couldn't just hop on Newegg yet).  Also there were these weekend Computer Shows happening frequently where multiple vendors showed and you could shop for deals. 

 

If you had friends into PC building, there was an endless amount of stuff to talk about.

 

Now PCs are boring compared to those days!

[eightbit]

1 hour ago, zzip said:

Now PCs are boring compared to those days!

 

I wholeheartedly agree. I used to be so pumped for the new stuff coming out. Working in places like Computer City and Comp USA at the time was like working in an amusement park...for a techie that is! The closest we have to that now is Micro Center I guess....but nothing today seems to excite me even 1/8 as much as it did back in those days. 

 

There were so many different odd devices (or what LGR likes to call "odd-ware") and they were so much fun to see. I remember the Syquest rep coming in and showing me the speed of the SyDrive (I think it was called) vs the zip drive. Playing MPEG videos on it without a hitch and all. I thought that was so cool. That's just one tiny example of the everyday world of gadgets I lived in at the time. Stuff that was new and exciting like the Obsidian 3D dual SLI card on one stupidly long card. I bought that sucker!

 

I still work in the field today for a major player (Nvidia partner) and we sell cards that are very cool and very unattainable due to the world issues....even for me. And even if they were available I doubt I would invest...just not so excited about them. My excitement probably ended around the GTX 7xx series to be honest....or maybe the 10 series at best.

 

 

[Keatah]

3 hours ago, zzip said:

Now PCs are boring compared to those days!

A nebulous time ago I began finding more excitement in software rather than hardware. I tend to like sandboxy type things where I can build, explore, configure, test, and such. Simulations! And the category has only gotten better since the early days.

 

I do not miss (not one eff'n iota) the 20 different manufacturers of graphics chips and soundcards. I have little desire to play specmanship or chase down a mythical 3FPS or a 2'C difference on heatsinks. I don't care for water cooling. And RGB is nonsense. These "advanced" configurations require too much babysitting. They're shop queens. Finicky. Expensive. Hard to upgrade. Tomorrow's low-end will far exceed what can be built today - no matter the cost or sophistication.

 

On graphics cards.. I lost interest when nvidia started coming up with nonsensical out-of-sequence numbers for naming, and seemingly endless granulation in core/memory speeds. The latest stuff is hot-running, power-hungry, unobtanium scalperware anyways. So not desirable. AAA games are all the same and not worth spending $2000 or more on a card.

 

Industry wants *ME* to buy AAA games and AAA hardware? They better make it available and affordable.. Otherwise I'm more than happy enough to play Air-Sea Battle on the 2600 and read about all this over-the-top hardware.

Edited March 8, 2022 by Keatah

[eightbit]

6 hours ago, wierd_w said:

QEMM was never magic for me.  Every time I encountered it, it was causing some kind of strange edge case to happen.

Granted, I worked at a mom & pop repair place during that era, and so my sample is surely biased toward the negative. (people dont bring working systems in to be serviced....)

 

 

I used the latest (last I guess) version of QEMM on this new build. Version 8 I think....I would have to check. 

 

I have a lot of stuff running on bootup (EZ-Drive, I/O drivers, CD-ROM, Soundblaster, DOS mouse driver and a few more things). When all was said and done my largest executable size was like 549K. I tried memmaker first and that got it to like 570K.

 

I used to manually do this stuff back in the day and I was about to make some attempts on my own but then I figured I would try QEMM just to see how well it would work. Well, it took a while to analyze things but it did the job and brought the size to 628K with no issues at all. I am quite amazed with that so this app is definitely a keeper.

 

 

Edited March 8, 2022 by eightbit

[eightbit]

On a side note I did find a link that still works for SciTech Display Doctor here:

 

https://www.vogons.org/viewtopic.php?f=13&t=15190

 

I figured I would try it on the crappy Orchid card. Well, it worked somewhat and it is much less crappy now. I don't have any before and after benchmarks, but it does indeed feel faster and the software does detect the S3 chipset on the Orchid card.

 

The card is still coming out though. I know for a fact that the Cirrus Logic card I have coming is much more capable than this card. But, I did find this software interesting and figured I would share the link while it is still available somewhere.

 

 

[NE146]

4 hours ago, zzip said:

That's what the PC world became.   Nowadays you upgrade your PC, you get mostly a faster version of what you had--  mostly USB, same HD/SSD interfaces, usually Same GPU interface.   CPU socket probably different.   But everything else is now integrated on the motherboard.

 

But back in the 90s the PC world was a circus,  competing standards (ISA, EISA, VLB or PCI bus?  IDE or SCSI? / Serial or PS2 mouse?)  you needed a separate soundcard, separate IO card (for floppy, harddrive interfaces), there were more manufacturers in the game,  more CPU makers than just AMD and Intel,  probably a dozen videocard manufacturers, etc.

We didn't have the fancy BIOSes we have today, most configuration changes had to be done by changing jumpers on the motherboard.    It was also a time of transition from DOS and all its idiosyncrasies to Windows 95 which felt like a complete OS for once,  and not just a fancy app launcher bolted onto aging MS-DOS (even though under the hood it was still much like that)

 

It was also an exciting time,  Mom and Pop PC shops popping up all over town,  Computer Shopper magazines the size of phone books coming every month which was always fun to page through to see what the latest prices were (this was before the internet was mainstream, and you couldn't just hop on Newegg yet).  Also there were these weekend Computer Shows happening frequently where multiple vendors showed and you could shop for deals. 

 

If you had friends into PC building, there was an endless amount of stuff to talk about.

 

Now PCs are boring compared to those days!

I mean yeah I lived throughout that entire time of course. That's exactly my point.. I see todays stuff as more or less the same computer, just streamlined and faster. ?

Edited March 8, 2022 by NE146

[eightbit]

1 minute ago, NE146 said:

I mean yeah I lived throughout that entire time of course. That's exactly my point.. I see todays stuff as more or less the same computer, just streamlined ?

 

Streamlined yes....with lots of prior compatibility obliterated

 

If you want to run 16 bit applications on today's machine's you need to use an emulator (Dosbox) or the real vintage hardware. This in my mind separates these older machines vastly from what we have today. Now in order to run those apps/games you need emulation or real hardware. Not much different from any other vintage computer we play with nowadays.

 

 

[Keatah]

1 hour ago, eightbit said:

I used the latest (last I guess) version of QEMM on this new build. Version 8 I think....I would have to check. 

https://winworldpc.com/search?q=qemm

https://en.wikipedia.org/wiki/QEMM

..you'll also find the v7 QEMM manual at winworldpc

[eightbit]

1 minute ago, Keatah said:

https://winworldpc.com/search?q=qemm

https://en.wikipedia.org/wiki/QEMM

..you'll also find the v7 QEMM manual at winworldpc

 

 

Yup I believe that is where I got it. Not sure why I used v8....ehh whatever. But it did work like a champ. Admittedly I never used this back in the old days on machines. I felt I never needed it. But I will say after using it that it really did the job. I have never been able to achieve that much conventional memory while at the same time having as much as I have running on this machine on bootup. Really sweet. I would have loved this back in the day if I had given it a go.

 

 

[wierd_w]

2 hours ago, eightbit said:

 

I used the latest (last I guess) version of QEMM on this new build. Version 8 I think....I would have to check. 

 

I have a lot of stuff running on bootup (EZ-Drive, I/O drivers, CD-ROM, Soundblaster, DOS mouse driver and a few more things). When all was said and done my largest executable size was like 549K. I tried memmaker first and that got it to like 570K.

 

I used to manually do this stuff back in the day and I was about to make some attempts on my own but then I figured I would try QEMM just to see how well it would work. Well, it took a while to analyze things but it did the job and brought the size to 628K with no issues at all. I am quite amazed with that so this app is definitely a keeper.

 

 

 I dunno. Ez drive always lives at the top of conventional anyway...

 

With a bios that stays out of the adapter region, the best possible free umb is 128k. [128k for video mem area, and 128k for system bios are not negotiable.]

 

In practice, its just 64k, because old games sometimes want ems, and you need a page frame.  

 

A 486 may be harder to get UMBs configured for inexpensively. I tend to use UMBPCI, and for obvious reasons that wont work here. There are some chipset specific utils for sis and opti chipsets that can do similar things though. I would try those...

 

Soundblaster utils should never be loaded high. Ctcm and ctcu will do stupid things if you try.

 

The big hogs are atapi drivers and mscdex. Emm386 is a bit fat at 4k use, but nothing compared to mscdex.

 

I would use ctmouse for the mouse driver. It weighs in at 1k of use.

 

I think i could get the 620k free without qemm.

 

Again, a bit biased against it.

 

[eightbit]

15 minutes ago, wierd_w said:

I would use ctmouse for the mouse driver. It weighs in at 1k of use.

 

 

You know, I have used ctmouse so many times with success. Actually, every time...at least in FPGA cores and a few machines in the past. I have used it on a Pentium 90 Gateway, a PIII machine some time ago and some other machines so I was well aware of it. So, it is of course what I tried first on this machine. But with this machine it would not work. Not at all.

 

I don't know if it were some compatibility issue with the I/O board or maybe the mouse (I am using a NOS Alps mouse...actually really nice!) but no go. I ended up using a Sigma mouse driver disk that someone posted in the Vogons forums as his go to when all else failed, and sure enough it works without a hitch.

 

I just try stuff until it works, and when it does I archive it as a part of my build drivers and stick with it.

 

Here is that thread after I could not get the mouse going with ctmouse:

 

https://www.vogons.org/viewtopic.php?t=54958

 

and link to the SigmaMouse driver that did work perfectly:

 

 

https://www.vogons.org/viewtopic.php?p=511259#p511259

 

 

 

Edited March 8, 2022 by eightbit

[wierd_w]

You can control ctmouse's loading behavior, if you know exactly what kind of mouse, and where its plugged.

 

It was probably a hang on detection. Skipping detection by feeding appropriate arguments to ctmouse would have been my next step.

 

I assume it is NOT a ps2 mouse, and is instead serial.  Serial mice come in 2 flavors; ms mice, an Pc systems mice. The ctmouse driver assumes ms mouse flavor unless told otherwise.

 

 

[eightbit]

15 minutes ago, wierd_w said:

You can control ctmouse's loading behavior, if you know exactly what kind of mouse, and where its plugged.

 

It was probably a hang on detection. Skipping detection by feeding appropriate arguments to ctmouse would have been my next step.

 

I assume it is NOT a ps2 mouse, and is instead serial.  Serial mice come in 2 flavors; ms mice, an Pc systems mice. The ctmouse driver assumes ms mouse flavor unless told otherwise.

 

 

 

Thanks! That actually makes a lot of sense. Admittedly I did not look at the options/switches for ctmouse. I just expected it to work and when it didn't I searched, found another driver, tried it and that worked and I moved on. I had bigger fish to fry and didn't feel like being caught up on a DOS mouse driver. I am not even sure how much the Sigma driver is actually using but I suspect it is lightweight....how much more than ctmouse I cannot say however. The Sigma driver installer does have a rather nice accelerometer test suite that I can't recall seeing in other installers back then that I thought was pretty cool.

 

I will probably look into ctmouse further as I set up an alt CF card. I found a 512MB card in my piles of junk today. One great thing about having that CF HDD solution. I can just swap hard drives and make different OS installs and configs on the fly. Ahh the miracle of modern technology

 

 

Edited March 8, 2022 by eightbit

[eightbit]

Now the question is what other cool stuff can I put in here? What other ISA or VLB boards are there that do something cool? I can add an ISA SCSI card for some future use I guess.

 

I also almost considered this which is funny and ridiculous at the same time:

 

https://texelec.com/product/bad-barta/

 

 

[wierd_w]

A scsi card would live in the adapter rom region. This would adversely affect the amount of UMBs that can be created, and thus, the free conventional after bootup. ASPI drivers would also need to be loaded.

 

A VLB ide controller might be doable though. 

[eightbit]

Just now, wierd_w said:

A scsi card would live in the adapter rom region. This would adversely affect the amount of UMBs that can be created, and thus, the free conventional after bootup. ASPI drivers would also need to be loaded.

 

A VLB ide controller might be doable though. 

 

 

The VLB I/O controller also contains IDE and floppy connections. I don't plan on adding any additional IDE. The I/O board provides one IDE capable to one master/slave...that was enough for me (HDD and CD-ROM). 

 

 

[wierd_w]

While not vlb, an etherlink iii isa card might be fun. Its a 10mbit ethernet card, with good dos support.

 

Sadly, dos packet drivers eat a lot of memory. However, having ipx/spx for retro lan play could be a nice option.

[wierd_w]

9 hours ago, Keatah said:

I enjoy the nostalgia I have with the old 486. Built it out decades ago, with the last bit being an XTIDE/CF interface. Maybe I'll through in a gotek.

 

Got tons of stuff in the mid-late 90's. Got a printer, scanner, a Snappy, a 4-way joystick adapter, 3rd hard disk with special IDE BIOS to go with it, 2nd parallel card, Zip Drive, some A/B switches, internal 14.4K modem, ergonomic keyboard, trackball/mouse, multiple gamepads and joysticks, extra custom proprietary Micronics branded memory card with 8MB (1MB SIMMS), parallel/serial buffer, and so much more miscellanea. Loaded the system up with DriveSpace, SmartDrive cache, a DDO, and other TSRs. VESA/sci-tech display doctor, all the necessary SB drivers, Guest.EXE for zipdrive, MSCDEX for CD-ROM, Network card and driver.. And more that I can't recall at this instant.

 

But all this can be overload. So much that I have thoughts about returning it to near-factory configuration, keeping only the SoundBlaster, 14.4 modem, and 2nd parallel card, as the only add-ons. Also removing DriveSpace, SmartDrive, and the DDO. The network card, and 2nd IDE card and 3rd HDD would go too.

 

Should I do any streamlining, I'd keep all the parts'n'stuff. And it would be based on nostalgia. I never got into PC networking (in earnest) till the Pentium II arrived. the 3rd HD was for Win95, more or less to try it out, never used it much. Disk compression was a big thing for me. So that's up in the air as to whether I remove it or not. Was near-magic!

 

I've imaged the current configuration, so it would be easypeasy to segue between different setups. All said and done - it was fun making everything work together.

 

Unless you explicitly need it for something, it is very hard to justify the extra weight of drivespace(3). It horks down 64k of ram all by itself. Removing the .bin files from the root is something i tend to do straight away, just for that reason.

 

Mscdex is also a hog. Eats 10k all by itself. Shsucdx is a bit fickle, but uses a lot less.

 

http://adoxa.altervista.org/shsucdx/

 

 

[wierd_w]

You know what.  It wasn't requested, but I will give a mini how-to here anyway.

 

Quick and dirty primer on manually massaging DOS memory, with MSD.

 

 

STEP 1:  Boot DOS without any memory managers loaded.  We want to see the naked, unmolested memory map.  As you can see below, this is JUST DOS with nothing else loaded or running.

 

We want to see what the memory map looks like.  MSD will tell us.

 

 

 

While this is inside a virtualPC virtual machine, it DOES give us a more or less accurate depiction of what a real memory map would look like. 

As you can see, we have an option rom in the adapter region between C000 and C7FF.  This is a very sizable chunk (~32k), and this is no bueno. This is likely caused by the virtual machine emulating a "newer-er" pentium III chipset.

If there was a way to make virtual box emulate a VX chipset early pentium, it is what I would be using here, as the memory map is MUCH cleaner. Incidentally, this ugly map is more real to life, so let's just roll with it.  This is why you should be more attentive to what chipset you are using, and have some inclination what to expect with different ones, when deciding on a retro computer build.  I am a big fan of early pentium VX boards, as they are "Sufficiently fast" and also "Sufficiently slow", that you can get the majority of games to work with little issue, while having a very open adapter region.  (Upon further inspection, this 32k option ROM is in fact the video bios.)

 

Additionally, we can see that MSD sees "maybe free" between E000 and E1FF.  This is most likely ESCD data, which is technically RAM that contains information about plug and play cards, etc-- and is a feature of such "newer-er" boards. It may or may not be possible to reclaim this area for UMBs, but if you do, DO NOT load windows.  In strict parlance, this area is owned by the system BIOS, and should not be walked on. Windows tries to read this area (ESCD) to configure its plug and play implementation, (since the bios advertises ESCD), and if you have programs in there, instead of ESCD data, well, you probably will get what you deserve for trying to be clever.  There is additionally an option ROM in memory at E200-EFFF.  I have no idea what this option ROM does, but it makes life more difficult by being there. 

 

For DOS only, it might be OK to try and reclaim this (ESCD area)-- because DOS does not use this location for anything at all.

 

This memory map tells us we have an unused gap between C800 and DFFF we can use for UMBs.  If we set up an EMS page frame, this is not much to work with-- maybe 32k of UMB?

 

That out of the way-- let's do this the "no frills" way, without any special tricks.  Just a CDrom driver, a mouse driver, and some memory managers.  With only 32k of UMB, the CDROM driver alone probably wont fit up there.

 

And as you can see, NO, the OakCDrom driver does NOT fit into the remainder of the UMB free, after DOS loads itself high.  It is FORCED to load into conventional memory.  

 

After some trial and error, if we enable the ESCD area for UMBs, we can get DOS and EMM386's page frame to play nice with the ATAPI driver, by putting the pageframe at C800, and including the ESCD area.

 

 

So far so good.  Let's see about getting MSCDEX loaded...

 

And, as we can see, there is no way in hell the MSCDEX driver is going to in the tiny 6k of UMB left...

 

Let's try SHSUCDX instead.

 

Well look at that!  It FITS! (barely.)

 

CTMOUSE uses a whopping 3k, so letting it live in conventional should be fine. We dont have 3k free, just some random bytes free in UMB.  We could STILL get it into UMB, if we include the monochrome video memory area at B000-B7FF, but then monochrome games will fail spectacularly. Sacrificing the 3k conventional seems like the best compromise.

 

 

 

With that dangerous option turned off, we have 615k free.

 

If we turn it on, we should have quite a bit more free UMB area, and we can attempt to load the command interpreter high using some actual voodoo (highlighted)....