Skip, thank you. It looks like the plot has thickened.

The PAL revisions on yours are the same as mine and both of our units have no FPU, however, your DIP switch settings are still different than mine. Yours is 6:off, 4:on. Mine is 6:on, 4:off. All others are the same. From the 4 photo examples seen, the only commonalities are DIPs 8, 7, 3, and 1. On the two with FPUs and the two without FPUs, the photos suggest that DIP 2 control the activation of the FPU, being that 2:on = w/FPU and 2:off = w/out FPU.

The DIPs which are inconsistent are 6, 5, and 4. Perhaps these set different cache invalidation schemes, or cacheable ranges of memory, etc.

As for the consistent DIPs, 8, 7, 3, and 1 - I bet one of these turns on/off a 2x PLL multiplier on the PCB (there's also an IC on the underside), how else would we get 25 Mhz from a 12 Mhz 286? The Cyrix DLC/SLC doesn't have a multiplier on its dye.

Yeah, one of these has to be a barb/flush switch.
Another one for clock doubling.
Third for fpu.
With so many switches, there must be cache toggle and cacheable ranges.

feipoa wrote on 2021-01-18, 07:59:

Skip, thank you. It looks like the plot has thickened. […]
Show full quote

Skip, thank you. It looks like the plot has thickened.

The PAL revisions on yours are the same as mine and both of our units have no FPU, however, your DIP switch settings are still different than mine. Yours is 6:off, 4:on. Mine is 6:on, 4:off. All others are the same. From the 4 photo examples seen, the only commonalities are DIPs 8, 7, 3, and 1. On the two with FPUs and the two without FPUs, the photos suggest that DIP 2 control the activation of the FPU, being that 2:on = w/FPU and 2:off = w/out FPU.

The DIPs which are inconsistent are 6, 5, and 4. Perhaps these set different cache invalidation schemes, or cacheable ranges of memory, etc.

As for the consistent DIPs, 8, 7, 3, and 1 - I bet one of these turns on/off a 2x PLL multiplier on the PCB (there's also an IC on the underside), how else would we get 25 Mhz from a 12 Mhz 286? The Cyrix DLC/SLC doesn't have a multiplier on its dye.

One thing I will say, is I cannot guarantee that mine works with the current DIP settings...
This is how it came and it looks to have sat untouched for many years, so I suspect they are correct, but I cannot say for certain.
The motherboard that it is on has suffered battery leakage, so I spent this afternoon adding bodge wires and have now identified a multitude of cracked solder joints. Once I get it up and running, I'll happily find out anything you ask.
This is my first foray into older stuff like this and I thought that it was quite an interesting little thing. Only paid £10 for it on the motherboard, so if it doesn't work, I haven't lost too much.
I have attached a couple of clearer photos of mine, as I realized that first one was pretty poor.
Do you know if this disables the onboard FPU, I was wondering if putting the onboard one in would somewhat make up for the lack of one on the Evergreen board.
Cheers
Skip

Yes, we don't know for sure on any of these modules of someone has goofed around with the DIP switches. The chances are low, but it is possible.

I cannot say for certain if putting an FPU on your motherboard while having the Evergreen 486 SuperChip installed will allow for the MB's FPU to work. In the Evergreen REVto486 manual, it mentions to remove the MB's FPU when using an upgrade unit, however that may only be for upgrade interposers with an FPU. I don't know.

It may boil down to: is the i287 compatible with the Cyrix SLC? I've never had an upgrade with the FPU missing like this before.

feipoa wrote on 2021-01-18, 00:53:

Most likely, I will trace out where each switch goes and try to make some guestimate as to what their purpose is.

Problem is that some of them are likely connected to the PALs, making it impossible, if you don't know what they do ..

Well, I can now confirm that mine works. I have it set up with a fresh install of DOS 6.22, so if theres anything you'd like checking out, please let me know.
Skip

Could you confirm if the L1 cache is working and ensure that the CPU is running at 25 MHz? This will let us know that the DIP settings have the external 2x multiplier enabled and the L1 enabled.

feipoa wrote on 2021-01-23, 10:20:

Could you confirm if the L1 cache is working and ensure that the CPU is running at 25 MHz? This will let us know that the DIP settings have the external 2x multiplier enabled and the L1 enabled.

Hi feipoa,
Apologies, I made a start on playing around with it, but have been crazy busy recently. I will hopefully have some time one night this weekend, so can have a look for you.
I now have a Siemens 80286 and an Intel 80287 that I can use to compare results to, which should be interesting.
As I say, I'm a little inexperienced with stuff this old, could you give me any suggestions for programs to use to verify the cache is working. I currently have the Philscomputerlab benchmarking pack on the CF card, but couldn't see anything that gave a definitive yes/no answer.
Cheers
Skip

Oh I wish. But like you, I have no time now, not even to assist with cache testing. Stand by...

No rush at all, when you have time to have a think, drop a reply and I'll have a play with it when I get a chance!
Skip

I'm in the process of upgrading my 5 general use home computers from XP POS2009 to Linux. There are two desktops in the office (one Mac Pro 2,1, one Operton 185), two laptops (T61, X201), and my garage/mechanic desktop (Prescott 3.8 GHz P4 640 I think). It was the Windows source code leak which finally got me off my butt to get this done. No Win 10 for me.

OFF TOPIC brain dump on my experience transitioning to Linux:
I've fiddled with Linux for the past 25 years, but always went crawling back to Windows as I find the level of user friendliness and setup effort to be undesirable. While there has been some progress, esp. with Ubuntu, in the past decade or so, esp. with respect to drivers and x-windows, it still feels like an alpha stage OS to me. Trying to implement just about anything has been taking hours and hours of reading through forums, later finding out that information was removed in my Ubuntu version, or some commands have changed, or whatever. The stress is turning my ear hair greyer. Nothing I do seems to work out of the box, there is even a very large dependence on graphics cards for desktop performance that was available with the first Windows graphics GUI accelerators. It is baffling to me. Linux wants to do all scrolling and basic desktop functions in OpenGL (why not do it like Windows GUI acceleration?), but even with OpenGL 2.1 and greater, the desktop performance results are all over the place. Low GFX mode has vanished. SCSI2SD won't work with my VIA USB cards, scrolling in Firefox is choppy on some cards but not the other, but the opposite is true for Chrome on other cards. 1080p video playback is a mess - some output drivers cause it to be a slideshow on some graphic cards and I can't figure out why. I've been at this for 7 weeks and am still at it. It seems deliberate that Linux is as non-user friendly as it is, as if it is designed like this to keep Windows riff-raff away. Does anybody really want to memorise the millions of possible setup commands? I suspect Linux will always be like this. Even the more Windows-like flavours of Ubuntu (Mate, Xubuntu, Lubuntu) are having these setup challenges. Caviat: Don't try to clone your Linux HDD if you've already installed that new HDD into the system and booted Linux so that Linux now sees that new HDD before the clone. Quick fix: move the HDD to another SATA port. Nuts...

Linux of the olden days was pain in the bottom.
Then at some point things clicked and it became feasible even for casual home usage.
The trick is to use preemptive measures - assemble computers from parts that are well supported by Linux directly, or there are matured drivers available.
Also, you are supposed to stay in sync with the OS - meaning - perform software and hardware upgrades according to distro versions and the ecosystem of related packages.
Going the other way around - trying to conform the OS to given hardware configuration gets you on a path you don't want to be.
Linux is not good at backward compatibility. This is Microsoft's game.

Most of my time in computing has been in Linux.
It is awesome.
But yes, not the best fit for your needs.

I have been sticking with the release repositories and am not entirely unfamiliar with Linux. If you are interested in my struggles, I have been noting my struggles on an Undernet IRC channel and simply dumped by curses into there as a means to cope with this usability nightmare. I use a lot of foul language, so that channel isn't for those trying to maintain a politically correct visage. I'm not doing anything out of the ordinary, nor am I trying to use Ubuntu 21.x on old hardware. I'm using 16.04 LTS, which is still supported.

I am sure you know the Linux ways.
In my experience redhel based distros worked better than Debians.
I still remember how nice fedora 12 was. Sh!t just worked.
It should handle well hardware from around year 2009.
I wouldn't mind checking your irc posts and expand my street vocabulary.

lol, ok. I need some time to dig through the channel logs as most of the woes are now in the past.

Superchip is a pretty old product. The earliest versions were from at least 1990. The 486 superchip is largely the same but with Cyrix instead of 386SX.
Even in the mid-90s, Evergreen had already scrubbed their support of any reference to this upgrade (a common problem with company websites on the early internets).
I checked usenet for the switch settings but still came up empty handed. In my opinion, the way that you will find these switch settings is by checking with old timers int he PS/2 community, or possibly PC-98 users.

I know it's a pretty long shot, but has anyone tried to contact the founder of Evergreen?

https://www.linkedin.com/in/mike-magee-4a778a7

feipoa wrote on 2021-03-07, 00:57:

I'm in the process of upgrading my 5 general use home computers from XP POS2009 to Linux. There are two desktops in the office (one Mac Pro 2,1, one Operton 185), two laptops (T61, X201), and my garage/mechanic desktop (Prescott 3.8 GHz P4 640 I think). It was the Windows source code leak which finally got me off my butt to get this done. No Win 10 for me.

Why did you move from win 2 lin just because of source code leak? Because of all evil hacker will aim to hack your PC using the bugs found in the sources? I use XP still as primary OS for more thar 15 years (upgraded as possible and tweaked 2themax) and I never had a problem with hack/infections just by an evil packet had arrived. When I need to run suspected executables I just run them in VM. As opposite I see in sources leak a good chance to keep XP alive on modern HW a there already was some attempts on winraid forum by hacking acpi driver and something else can appear.
Together with Win, DOS and other I already have Linux in multiboot (I settled on Debian). Yes there was some problems that wasted a lot of time googling, reading forums and blind shots but I struggled with it and making it working, I have no problem with recompiling kernel to make some specific patch to a driver to make it work. But I'm a bit tired that as linux/kernel develops the old things breaks again and again - those are not synced in current repo and that still waste time with seeking of solutions. But generally I don't complain on linux and I can use it for few specific tasks I cannot do (e.g. no such tools) in Windows. But I use a huge set of windows-specific applications, some of them are bonded with specific HW that I want to keep using so I can't just fully switch to Linux without having alternatives for such apps. And not all is working in Wine, even in VM so well.
But for people who just use Internet, Office and not much else the Linux can serve as well the Windows (on proper HW, modern Linux GUI don't run well on old comps) and I would prefer it before W10 spyware-crap.

RayeR, sometimes I simplify reasons when they are off topic like this. It is more than just the source code leak. XP isn't provided security updates any longer - last was in May 2019. My wife has been making credit card purchases online on XP. The only non-Chinese updated browser which seems to work well in XP is MyPal, K-meleon, and maybe Roytam's port. These browsers all have their limitations in what works well on the modern internet. Another issue I have with these browsers is that once the browsers uses about 1.2 GB of memory, it tends to hang up, even when there is plenty of memory remaining. XP sees 3 GB and has the PAE enabled. The /3GB switch has issues as well, like the memory card drivers don't work. Another issues is that I cannot use Windows explorer to delete photos on my iPhone SE gen1 - I can only copy them over, then I have to delete them manually on the iPhone. Then there is the issue of software not installing on XP. Bought a printer/scanner and the drivers don't install. Putting it all together, I decided it was time to move on. I also looked into upgrading to XP 64-bit, but there is no straight upgrade path. I would have to format, install the OS, and re-install all apps. If I have to do that, I just as well switch to Linux. Now I can use all 8 GB on this laptop.

I've installed Ubuntu 16.04 on 4 usable systems, and 18.04 on two usable laptops. Setting it up to run how I want it was a nightmare and took weeks of messing around. I still have XP on another partition on all these systems, except for the MacPro 2,1, which has Lion, El Capitan, and Ubuntu.

Yes, regressions in Linux are all too common. I'd prefer that they not push subsequent OS revisions so fast and focus more on regression testing, even if this means a LTS release every 5 years instead of 2 years.

Wine is a nightmare. I try to avoid it unless absolutely necessary. I set it up to work with convert.exe.

Finally, I will begin work on this Evergreen SuperChip I have. I pulled the 286 out of the closet, desoldered the PLC68 and soldered on a PGA-68. The SuperChip appears functional with the existing DIP switch settings, but I must remove the motherboard's 287 FPU even if the SuperChip is without FPU. I'm running the motherboard with a 50.0 MHz crystal oscillator, which puts the FSB at 12.5 MHz. CHKCPU detects the CPU at 27 MHz, but that should really read 25 MHz. Assuming that the SLC doesn't have any sort of clock doubling feature like the SXLC chips, this would imply that the SuperChip has so some of custom PLL made out of its onboard PALs to double the FSB.

With the SLC running at 25 MHz, I noticed the surface temperature gets to 65 C after just a few minutes. This certainly seems rather warm for only 25 MHz.

Up next will be desoldering the SLC-25 and soldering on the SXLC2-50. The SXLC2-50 has its own clock doubling, so the final CPU clock would be 12.5 x2 x2 = 50 MHz. I bet the surface temperature will increase further, requiring a heatsink or heatsink/fan. If the new CPU works, I'll move on to soldering in a Cyrix FPU.

Aside from practice runs with QFPs, this will my solder paste debut on anything I intent to keep in working order.

What has been perplexing me about my 286 is that it cannot boot from floppies using a standard Harris 286-12 or 286-16 CPU. It tries to boot, but just hangs there. If I boot to a DOS prompt using the HDD, I can use the 1.44M floppy drive just fine. The interesting part of this observation was that if I use the SuperChip 486SLC CPU, I can boot to 1.44M floppies without issue. What could be causing the system not to boot to floppies with a standard Harris 286?

Does it get as far as "Starting MS-DOS..." or whatever message whatever OS put on the bootblock? ... if it goes past that, does EMM386 try to load do you think? or maybe stacker/dblespace even if you just did a sys A: from a system that had them installed and no config.sys or autoexec.bat. (view hidden files and if there's dblspace.sys there or similar then yeah, it did that)