The Post Your Old/Retro Builds Thread

w1retap

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Just finished up this Efika PowerPC build using a bplan Efika 5200b + Radeon 9250. It runs MorphOS.

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w1retap

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Yes, it is a Power PC 5200B CPU, as in Motorola/IBM/Apple type processor of the era. The PCI slot does include the AGP riser. Not 100% sure how it works as I haven't looked into the design used, but it works lol.
 

Red Falcon

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PowerPC as in the CPU's that Apple used before they went to Intel (and then their own in-house SOC's)?
Is the AGP riser in a PCI slot if so how does that work?

Anyway looks really neat!
Apple wasn't the only company to exclusively have computer systems operate with IBM and Motorola PowerPC CPUs.
The PS3, 360, Gamecube, Wii, Wii U, Yellow Dog workstations, and many IBM servers and supercomputers use/used the PowerPC ISA.
 

GiGaBiTe

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The PCI slot does include the AGP riser. Not 100% sure how it works as I haven't looked into the design used, but it works lol.

AGP is a superset of the PCI specification, and must behave like a PCI device when the card is first brought up before switching into whatever AGP mode it was designed for. But that switch doesn't need to happen, you can wire up an AGP card to a PCI slot with an adapter and have it run in PCI only mode, with the obvious caveat of severe performance degradation. 3dfx did this with their VSA-100 video cards, like the Voodoo4 4500, Voodoo5 5500 and even the Voodoo5 6000. They just used an AGP 2x slot as a fast 66 MHz PCI bus.

The Radeon 9250 is an AGP 8x card designed for transfer speeds of 2133 MB/s and you're choking it down to 133 MB/s of a 32 bit 33 MHz PCI slot, a ~93.8% reduction in bandwidth. But since that bandwidth is shared due to PCI being a parallel drop bus, the actual bandwidth available is lower.

There are some cards this approach probably wouldn't work with, like the janky late "AGP" cards like the HD46x0 and some Nvidia 7000 series cards that used PCIe2AGP bridge chips. These cards are known to have compatibility issues with normal AGP motherboards.
 

Deadjasper

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I have an old Merlin i386 board with a Co-processor and maxed out memory in mothballs and I'm thinking about bringing it back from the dead. Back in the day i rented this system running Windows XP for several years and made a ton of coin even tho it was beyond slow. Thinking I should resurrect it for old times sake.
 

GiGaBiTe

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I have an old Merlin i386 board with a Co-processor and maxed out memory in mothballs and I'm thinking about bringing it back from the dead. Back in the day i rented this system running Windows XP for several years and made a ton of coin even tho it was beyond slow. Thinking I should resurrect it for old times sake.

You didn't run Windows XP on it, because Windows XP won't run on anything less than a Pentium. Windows XP requires CMPXCHG8b and CPUID, the former of which was introduced on the Pentium and the latter which only worked properly on the Pentium and other 586 class processors.

The slowest CPU that Windows XP will run on is the Pentium Overdrive 63 MHz, which was an expensive upgrade for Socket 3 486 machines. This was basically a cut down Pentium core bastardized with a 32 bit memory bus to work on the 486 architecture. I have the 83 MHz version of the POD, and I've installed XP on it just to see what it would do. It is PAINFULLY slow, installing the OS takes hours and booting to the desktop takes 20-30 minutes. And since XP doesn't have proper support for the ISA bus and VESA Local Bus or any of the hardware from the 486 era, you aren't getting any sort of DMA or accelerated video, which makes it worse.

The last version of Windows that will run on a 386 of any sort is Windows 2000, though I wouldn't recommend it.
 

Deadjasper

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You didn't run Windows XP on it, because Windows XP won't run on anything less than a Pentium. Windows XP requires CMPXCHG8b and CPUID, the former of which was introduced on the Pentium and the latter which only worked properly on the Pentium and other 586 class processors.

The slowest CPU that Windows XP will run on is the Pentium Overdrive 63 MHz, which was an expensive upgrade for Socket 3 486 machines. This was basically a cut down Pentium core bastardized with a 32 bit memory bus to work on the 486 architecture. I have the 83 MHz version of the POD, and I've installed XP on it just to see what it would do. It is PAINFULLY slow, installing the OS takes hours and booting to the desktop takes 20-30 minutes. And since XP doesn't have proper support for the ISA bus and VESA Local Bus or any of the hardware from the 486 era, you aren't getting any sort of DMA or accelerated video, which makes it worse.

The last version of Windows that will run on a 386 of any sort is Windows 2000, though I wouldn't recommend it.

Wrong. I once ran XP on 386. Board had a coprocessor. Not sure if it was needed or not. Rented this box to an ancient lawyer for years. Took forever to boot and ran slow as molasses. He was about as fast as it was so they were a perfect match. Still have that MB. Thinking about resurrecting it.
 

GiGaBiTe

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Wrong. I once ran XP on 386. Board had a coprocessor. Not sure if it was needed or not. Rented this box to an ancient lawyer for years. Took forever to boot and ran slow as molasses. He was about as fast as it was so they were a perfect match. Still have that MB. Thinking about resurrecting it.

No, you didn't run XP on a 386. It is not possible due to missing CPU instructions. Having a 387 FPU is not going to make a difference.

please do and put xp on it so we can see that its actually possible.

It is not possible. The last version of Windows that will run on a 386 is Windows 2000.
 

pendragon1

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No, you didn't run XP on a 386. It is not possible due to missing CPU instructions. Having a 387 FPU is not going to make a difference.



It is not possible. The last version of Windows that will run on a 386 is Windows 2000.
he swears hes done it, i want to see it...
 

GiGaBiTe

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i know but wouldnt you like to know how he got it to work when no one else can?

I've seen people go hog wild to the fullest extent possible trying to get it to work, There's really nothing he'd do that would at all be interesting.

Several people have tried hex editing Windows DLLs, executables, the kernel, the boot loader and every other part of the OS to remove CMPXCHG8b and replace it with compatible 486 instruction(s). They had no success and were going at it for years. What makes it even harder is later Windows XP patches started to use SSE and then SSE2 instructions, so at most you could probably go up to SP1 before you start running into more instruction set problems. The 486 has nothing close to SSE, so emulating those instructions would be painfully slow. The number of files you'd have to patch would be comically large.

The other thing limiting would be memory. Windows XP requires an absolute minimum of 64 MB, something which the large majority of 386 motherboards never supported, and 486 boards didn't see until the mid 90s. You'd also need a 386DX for that, because the 386SX in addition to having a 16 bit data bus, also had a 24 bit address bus, limiting it to 16 MB of addressable memory total.
 

Deadjasper

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I've been nursing a bad tooth. Couldn't get it pulled for 15 days due to infection. Got it pulled and now a week later the gum still hurts like hell. I'm having trouble finding a PSU. I probably have one buried somewhere, just gotta find it. Bare with me.
 

Deadjasper

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Just ordered an ATX to AT adapter from eBay. New AT PSU's are available but are a bit pricey. I have plenty of ATX PSU's.
 

Deadjasper

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Had to put this project on hold for a bit due to other issues coming up. I have to round up the rest of the parts that are compatible with this board like video card, mfm controller and HD, floppy controller (or were those built into the mfm controller?)

I have a shit load of old boards and other assorted junk but nothing that goes back this far. :confused:
 
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