Dang, that DTK+SXL55+ISA of yours make my Panda BL3-75+VLB look like an under fertalised flower. Nonetheless, I'll build a system out of it anyway. I need to ensure my Buffalo works at 3x33 in other systems before I'll put in the effort to swap out the IBM CPU to a known good 110 MHz sample. Yes, I need to test my Symphony w/SXL2. I only have available my super sandwich SXL2-66 though download/file.php?id=48958&mode=view . To access my QFP SXL2-66 would require a painful system teardown.

pshipkov wrote on 2022-03-13, 23:22:

What is the top most ISA card ?

Fancy Gotek. Haven't seen one with front display.

Top most ISA card is probably the SD2IDE board with a rear bracket mount.

You can find these Gotek’s on eBay in four or five different colors for a decent price, I rarely find myself using it but I’m sure it will come I. Handy at some point. This one was supposed to be “beige” and they offer one in a yellowed beige as well 🤣.

@Feipoa
Wow, I thought you have a rare drop-in DRx2-66 / SXL2-66 132-pin upgrades until now.
So you completed the interposer ?
I remember reading a thread about it but my understanding was that things didn't work really.
Can you confirm which schematic i can follow to recreate the contraption ?
Have one of these Socket 2/3 DRx2 CPUs around here which can be put to a good use.
Render me very interested to explore that.

---

@Chadt99
So this is a CF2SD adapter that has both outward facing CF sloth and some IDE cable on the back. Is that it ?
Haven't seen this model.

Thanks for the gotek info.
My gotek fell silent recently - i think i burned it by connecting it to the Tandy's FDD controller directly.
Long story short.
May pick one of these more fancy ones as a replacement one day.
I also rarely use floppies.

Btw, it may be good if you share the brute-force tests you completed with the 200MHz rig - for legitimacy. : )

pshipkov, too many threads, too many posts, too much time past. I cannot blaim you for not remembering what who has, etc. I have not completed the custom pga-132 to PGA-168 SXL-only interposer, nor has anybody else to date. The design was shown to work, just need someone to produce the PCB.

Shown in that image is an existing PGA-132 to PGA-168 for SXL, but 5 V only. Then I have added a customised 3.6 V VRM interposer. I've had to remove whatever glue logic was on the VRM interposer and reroute a few wires. Plus he original PGA132 to PGA168 interposer has some logic onboard which mucks with the cache flush that we don't really need. I haven't removed those ICs and rerouted because I don't have a spare. I beleive all these interfaces cause issues at 80 MHz. So I think this unit only works up to 70 Mhz, while the Evergreen QFP SXL2-66 runs at 80 Mhz. At least this is how I remember it. I'd have to double check my notes.

I have a drop-in DRx2-66 and SXL2-66.

pshipkov wrote on 2022-03-14, 18:15:

-- […]
Show full quote

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@Chadt99
So this is a CF2SD adapter that has both outward facing CF sloth and some IDE cable on the back. Is that it ?
Haven't seen this model.

Btw, it may be good if you share the brute-force tests you completed with the 200MHz rig - for legitimacy. : )

Yes SD card slot out the rear.

For sure I can provide the full dosbench suite on the current setup with the Biostar UUD, or which specific tests would be the brute force tests?

@Feipoa
Ok, i see.
so if the contraption actually works at the end i may attempt to replicate it. need to refresh my memory with that other thread.

@chadti99
my point was that your ide2cf adapter seems to have cf slot and 40 pin ide interface. this is what i found unusual.

as for the tests - i meant the q1, lw3d, cpp, ie4 in parallel at 200mhz on air which is just impressive.

pshipkov wrote on 2022-03-14, 23:10:

@chadti99
my point was that your ide2cf adapter seems to have cf slot and 40 pin ide interface. this is what i found unusual.

as for the tests - i meant the q1, lw3d, cpp, ie4 in parallel at 200mhz on air which is just impressive.

Ah I think the confusion is because this is an SD card and not a CF card to IDE adapter.

For the test I can run everything but the IE4 part, I could open it I guess. How should I share the results? I could maybe shoot a video with my phone on a tripod or just some photos? Agreed though, it is impressive.

I see. Ok SD but not CF. Makes sense.

I usually do a quick video with a phone, but up to you really if you want to do video, or just screenshots, or not do it at all.
I thought that you are reaching the top with this rig and it is worth showing the result on the Fastest 486 thread for example.

Yep def want to provide some more results. In the UUD board it doesn't break any records but it's really stable. The UUD pulls 21.8 in Quake on stable settings, it's possible the LSD board can pull 21.9 with DOS 6.22 on stable settings.

The disappointment begins with the MS-4144, is she dead? First time with post card. I’ve tried flashing a couple different bios files, a couple known working CPU’s. No sounds, no codes so far.

does not look good.
can be badly aged bios chip.
swap it with one from the LS mobos and see if that makes a difference.
i would also insert a trusted memory stick.
i dont trust these post cards much. they are hit or miss.

Yah thought for sure it was just needing a new bios chip. No luck so far, I seem to get different results, but still no codes, if the card is inserted in either PCI or ISA. Get the same results with the bios chip pulled.

The CPU gets warm, I should probably check for voltage to the bios. The CPU socket feels “crunchy” for a lack of a better term when closing the latch.

*No luck with an LS bios
*4.85v to bios socket
*VRM seems good
*De-lidded the socket per pshipkov’s instructions, don’t see any bent pins.

In other news I did find a ram module in my pile that would boot my LSD board at 212/Fastest @180 but unable to complete a Quake timedemo. Found some of those LG modules and ordered, hoping to get that stable!

Ok, this mobo looks a lot like it is gone for good.
Tiny chance it is one of these black capacitors around the CPU socket, but is a stretch ...

I have few that seem to be doing the DRAM TIMINGS = FASTEST @180/200.
They are not exclusive. Many of these LG modules are capable of handling that.
Let me know if you get unlucky with your current purchase - i can pass you some.

Can someone PM me the source for these magic LG memory modules?

Link sent.

(ahem ... i am open to accepting donations from the grateful population btw)
: P

pshipkov wrote on 2022-03-19, 22:45:

Ok, this mobo looks a lot like it is gone for good. Tiny chance it is one of these black capacitors around the CPU socket, but i […]
Show full quote

Ok, this mobo looks a lot like it is gone for good.
Tiny chance it is one of these black capacitors around the CPU socket, but is a stretch ...

I have few that seem to be doing the DRAM TIMINGS = FASTEST @180/200.
They are not exclusive. Many of these LG modules are capable of handling that.
Let me know if you get unlucky with your current purchase - i can pass you some.

If anything this might be a good donor for a socket with the retention clips for my LSD board.

I’ll keep you posted on the LG modules, I might have to take you up on that offer.

The LG modules I found didn’t have what it takes to run at 212/Fastest@60FSB unfortunately. Talking to pshipkov on maybe testing one of his.

In other news I picked this guy up. Hoping to test at 50MHz FSB or 125MHz with different coolers. Any ideas on removing the remaining epoxy?

My plan is to remove all the surface components as I’ve read in the POD100 thread it restores the 2.5 multiplier, even with the fan removed.

With teetering on the edge of stability like this, there could be minor variations in your motherboard or its components which cause your LG modules not to work at 212/Fastest/60MHz, rather than the modules themselves. It is possible that if pshipkov sends some of his modules to you that the problem persists. It could also be that your modules work fine w/pshipkov's setup. If shipping is cheap and interest still ripe, test it and find out.

As for removing the POD's epoxy, get yourself a fresh 1.0" or 1.5" chisel from Home Depot, line it up with the the flat edge parallel to the ceramic, and tap with a hammer. Ensure the chisel has no burrs, or you'll add some artwork to the ceramic. Also remove the chip from the motherboard and place it against a fixed object.

feipoa wrote on 2022-03-26, 19:38:

With teetering on the edge of stability like this, there could be minor variations in your motherboard or its components which cause your LG modules not to work at 212/Fastest/60MHz, rather than the modules themselves. It is possible that if pshipkov sends some of his modules to you that the problem persists. It could also be that your modules work fine w/pshipkov's setup. If shipping is cheap and interest still ripe, test it and find out.

As for removing the POD's epoxy, get yourself a fresh 1.0" or 1.5" chisel from Home Depot, line it up with the the flat edge parallel to the ceramic, and tap with a hammer. Ensure the chisel has no burrs, or you'll add some artwork to the ceramic. Also remove the chip from the motherboard and place it against a fixed object.

Great point feipoa, def could be small differences between our boards, it will interesting to find out. If his module doesn’t work for me I’ll send him mine.

I’ll see about finding a chisel!