Phido's 486 Build log + History + experiments

Discussion in 'Retro & Arcade Worklogs' started by Phido, Nov 23, 2019.

  1. Phido

    Phido Member

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    For those unaware, I have a 386 build log https://forums.overclockers.com.au/threads/386-buildlog.1234684/.

    The 386 had a special place for me, it was the first PC I built myself, my previous first computer I purchased myself was a Wang 286 (build new around 1988, purchased by me around 1990), which by the early 1992 I had well and truely out grown the 286 and was looking for more. As I recall I built it around 1992-3. With the budget of 13 year old, mowing lawns, cleaning offices. With such a limited budget, it was slow, even for the time period. But I coded, I used 3dStudio, Pov ray, played 2d scrollers, BBS'ed. The most modern thing it had was a 420Mb hard disk which was 2nd from the top at the time and seemed limiteless.

    My re-creation which started as a pretty average 386 Fullsized AT, but was put into a modern black Awyn mATX case, 32Mb parity ram (previously told impossible on a Chips and Tech chipset), ISA video accelerator, 486DLC 50Mhz with a 50Mhz bus and 196Kb of L2 cache (also impossible), a range of Mathcoprocessors, 32 Gb SD card storage, AWE32 sound, Wifi ethernet, external USB power ports and gotek with a 5 1/4 floppy, with a 12 Mhz ISA bus. It will run Win95 and play jazz jack rabbit II, and go all the way down to a slow 386. It was a very modern "386".

    This 486 is something different. I was able to purchase the same case the my original 386 DX 25 was put into.

    [​IMG]

    Now this case isn't timeless, they particularly appeared around the early 90's and disapeared quite quickly. Nothing particularly special about the case, generic whitebox. But the time period puts it bang on around 1992-3. The current specs of this machine pretty much represented the top of 1992-3.

    486 VL bus motherboard
    486 DX2 66 Overdrive
    8Mb ram
    520Mb IDE hard disk
    VL bus combination VGA/IO card.
    Combination 51/4 and 3 1/2, Something I've always found interesting
    ISA cat 5 network card.

    Apparently its having issues booting. But the case and the insides are absolutely immaculate. I've never seen anything retro in this condition. It must have been vacuumed sealed.

    In my possession, I have:
    486 Socket 3 board with PCI - Supports 30 pin and 72 pin ram
    An evergreen AMD powered 133Mhz 586 processor.
    Being a PCI board you can basically plug a whole bunch of cheap adapters into this.
     
  2. Vanne

    Vanne Member

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    Wow, I've never seen one of those combo drives before.. I thought it might have been CDROM/floppy.. lol.. nice one. :)
     
  3. Flamin Joe

    Flamin Joe Member

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    Combo floppies are the best. :thumbup: I've got a Teac FD-505 which has the drives in a reversed order to the one above and the coolest thing about these dual drives is the 5.25" disk mechanism. You get so use to 5.25" drives having the good old turn the handle design to pop the disk out but this feels space aged in design where the disk simply pops out from pressing the button. :)

    It's also quite amazing to look at how far the 5.25" drives came with this unit from being double height 5.25" drives such as the Tandon TM-100-2A's found in the original IBM PC, to single height 5.25" drives in later PC's down to these which take up just half the height of one 5.25" bay.
     
  4. OP
    OP
    Phido

    Phido Member

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    I've never had a combo floppy. It is an incredibly neat solution. It appears to be working. I love it. It could do with a retrobright, its probably off something older, like a 386, I have a compaq 386 with a single 5.25 with a simular mechanism.

    So I powered this guy on. And she boots. Well, she boots and then complains there is no OS. It looks like it isn't looking for a MBR on the HD or if it is the HD is dead. But otherwise she is in good shape. I am amazed how clean this computer is. Its immaculate. There is no dust anywhere. It is a lovely case, in perfect condition, it looks more NOS than 2nd hand. I unfortunately brutally butchered my case. At somepoint I wanted it black, and had tried and failed to spray paint it correctly. Also I had issue fitting some cards so I had attacked the card slots with tin snips and made a mess. No that case was gone long before it was thrown out, but this one is mint. However, the turbo button doesn't seem to flick between speeds, which seems more like a configuration issue. This case has a nice soft AT power on/off, with a button more ATX sized and the big circuit breaker ones on most AT cases. The turbo and reset and power are all the same size.

    Now to choose between the Motherboards:

    • I have a NOS 486 3 PCI/4 ISA with a UMC 8881F chipset, PM486PU-S5, 11/1995.. Its quite a sweet board. The only thing its missing is the ability to generate 3.4V for DX4 CPU's. Its come fitted and configured with a AMD 486 DX40. 32Mb of FP Parity ram. It has embedded ide and floppy and coms. 256kb 15ns cache. Apparently these support up to 66mhz bus.
    • The existing VLB board. Which is a GA-486VF Rev 8A. http://www.motherboards.org/files/manuals/47/486vs8a.pdf. 3 VLB, 30 pin ram, it however is full socket 3 which supports all 486 cpu's and can adjust voltage. This one supports up to 50Mhz bus, but not sure how likely it is with VLB. Its currently fitted with a DX2/66 and 8mb of ram.
    which then flows onto
    • The VLB setup has a combination Video/IO card with IDE and coms ports, so replacing the video also means replacing the IO. I don't really want to start investing in VLB cards.
    • PCI is much easier I have variety of PCI graphics cards, a 8mb ATI Rage and a 8Mb PCI Savage4, and everything is integrated into the motherboard for IDE/Coms.

    I kinda liked the Idea of PCI 486 because well, PCI parts are cheap and common. You could put in a 3dfx card, a usb card, various vga cards. VLB is limiting and the ISA stuff is really limited to older parts except soundcards.
    I'm thinking I will test out both boards..

    I never had a 486. I had a 386Dx25 with mathcopro 4mb of sipp ram, which was slow, and I waited until basically mid 1996 and jumped into a Cyrix 166+ (which was really a fast 486 in a Pentium board). It wasn't a bad jump, one of my friends jumped into a Pentium 60 that was a frustrating machine. I never upgraded that box with a new CPU either. I jumped out of that into a slot 1 Celeron A with a healthy overclock.

    So while everyone was playing Doom and wolf3d all those other cool games, I really missed the boat. My 386 was purchase probably 1993, so a low end 486 setup would have been a viable option, but I didn't have the cash as a kid, and I was jumping up from a 8Mhz 286 with 640kb and EGA. (All of my PC were self funded with lawn mowing and office cleaning doctor surgeries.) So VGA and 386 sounded wonderful. But windows 3.11 was unimpressive on it, and 95 ran, but was impossibly slow, things like web browsing was impossible (particularly with my 2400 baud modem). Even with my red hot 132PGA setup, with a 50Mhz 386 or even 486DLC, it is slow. Back when I had the 386, I ran a copy of 3dStudio, which I thought was incredibly novel at the time. I did my year 10 "build a bridge" project using it, and created a 3D model with raytraced renderings including wood texturemaps which we printed out on a color mac inject printer. But the renderings at even low 320x200 would take ages, hours.

    I had seen 486's, they were fast. Probably twice as fast at the same clock in many tasks. The FPU was dramatically faster, maybe by a factor of 4. The DX2's and the DX4 were mind blowingly fast. Doom was very playable on a 66, and silky smooth on a dx4. Windows flew on each platform, and I remember web browsing on a 486 at a computer fair (it had 24mb of ram which helped a lot).

    So I often wondered what if I had gotten a 486. It was an incredible platform. Lobbing in at 486 at 20Mhz, it then quickly went to 25, 33, then 50mhz. Then we had the AMD/Cyrix/UMC 40Mhz variations, then the clocked doubled DX2/50, dx2/66 and the dx2/80, then the clock tripled DX4/100 and 120Mhz, then the clock quadrupled AMD133Mhz and 160Mhz, the Cyrix 586's and of course the Pentium Over Drive up to 83mhz. But compare that first 486DX25Mhz to the last AMD5x86-160.. That a total of 8 times the performance of the introductory CPU, in the final form. Every year (or 2) or so, you could pickup a CPU, drop it in and get basically double the performance. Keep your ram, keep your mainboard most likely (many 486's were designed to be drop in upgrades), your HD, all your accessories. The final forms, really were faster than those old 60 and 66Mhz Pentiums, 75 Mhz Pentiums and most rivaled 90Mhz Pentiums in integer performance. More importantly older mainboards had some value, because you could thrown in a 133mhz amd into nearly any of them and it would be a reasonable low end box.

    This setup will likely be paired with:
    CD drive
    100Mbps network (although I do have a PCI 802.11b adapter somewhere...)
    32 or 64Gb SD card on IDE adapter

    I am also interested in this running some BBS software.
     
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  5. badmofo

    badmofo Member

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    I love a 486 so am watching all of this with interest :thumbup:

    My personal opinion is that 486 = VLB, but that's probably just nostalgia because it's what I was lucky enough to get my hands on. Anything other than the most modern VLB boards are a pain to configure and like you mentioned there're a lot more options RE VGA, etc with PCI, but I feel like anything beyond a VLB system @ 66MHz is just a wannabe Pentium :p. I had a PCI based 586 133 later and it wasn't nearly as memorable as the SX33 or DX266 that came before it.

    There are some awesome VLB VGA options but I assume they're getting hard to find now - I haven't looked for years.

    Any, if you're having fun then you're doing it right regardless of the BUS. Looking forward to hearing which way you go.

    edit: fixing typos - I used to write so well, but post kids my brain doesn't have the same ability to concentrate or thinky think
     
    Last edited: Dec 8, 2019 at 5:22 PM
  6. Pierre32

    Pierre32 New Member

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    I can relate to missing out on a generation or two of hardware back in day. We had made the jump from an (admittedly quite pimped) XT clone to a P200. So my builds now are partly nostalgia, and partly about being able to experience things I didn't know about back in the day, or just couldn't afford.
     
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  7. Vanne

    Vanne Member

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    My buddy had a creative blaster VLB card.. that thing hauled... at least back then it did, when i had a lowly crappy 386 33mhz thingy-me-bob. (buit id did play EOB on that puppy and that was epic)
     
  8. OP
    OP
    Phido

    Phido Member

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    I totally get people having specific views on a 486.
    • Early 486's with ISA or EISA buses. ISA buses really slow up a 486 box.
    • Mid 486's with VLbus - a bus purely for the 486.
    • PCI 486 were very late in the game and were really overflows of pentium tech. This bus just happened to live a long life and has lots of ongoing support for quirky cards etc. So can be useful for comparing 486 and more modern stuff. Also obviously better for dealing with high bus speeds than VL bus.
    I've been re-reading a lot of reviews on the early 486 systems and processors. I can see why people preferred the proven cheap 386 platform. The reviews of 486SX20's were pretty disappointing, getting soundly pounded in ALU by the average 386DX33 let alone the 386DX40, and with no FPU, and the 486DX being quite a high priced item until the clones came, why people still bought 386's long after the 486 was on the market.

    Which is why cyrix was able to push performance of the 386 platform with the 486DLC and other variants which had an on chip cache. It even got clocked doubled and clock tripled variations as well. But while quicker than the regular 386, they didn't really make it a full 486, and the FPU performance was miles off. Still probably better than a 486sx20. But I didn't get either the 486DLC or SX2 or a real 486, I just skipped it.

    I really want to do a bit of comparison with my 386 and the 486 as well and nut out performance differences between them. Oddly my 386 is in a new modern case and my 486 is in early 90's beige.
     
  9. Flamin Joe

    Flamin Joe Member

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    Me too we went from an XT clone to a 486. It's not just the hardware you miss but the software as well. So many games my poor old XT couldn't play I missed out on and then when I got the 486 there was only so many you could catch up as new games got released.
     
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