VOGONS


First post, by Vipersan

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So the beautiful MB-8500TTD I recently bought from ebay has arrived ..but on power up ...I got nothing.
A visual cursory scan of the mobo revealed it to be in good order ....a deeper scan with a jewellers eyepiece revealed more.
There is a quite wide trace which is open circuit with a small part of the trace vapourised.
I removed some components in the area including a power FET NDP 603AL ....a Double Diode BYV118-40 to gain access ..
both mounted on small ally heatsinks..
and a 100uf 16v cap
I was then able to repair the trace ,,,and clean the area with ISO.
The components cold checked and the BYV118 was shown to be short circuit.
I shall therefore replace all 3 of these components.
But before this I needed to check for short circuits which could cause enough current to be dumped that it could vapourise a 1.5mm copper trace.
Finally Isolated it to a green electrolytic cap Sanyo brand 1500uf 6.3v
Totally short circuit internally.
Hopefully this lovely old mobo will live again...but certainly not untill the BYV and NDP replacements arrive from ...you guessed it...China.
rgds
VS

Last edited by Vipersan on 2019-08-24, 11:59. Edited 2 times in total.

Reply 1 of 30, by Vipersan

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A question regarding this socket 7 mobo ..
The psu for this board is AT ...but ..the traces and pads also exist for ATX ...
Has anyone on the forum ever retro fitted an ATX 20 pin socket to this or similar motherboard ?
It was obviously designed with this in mind but for some reason it wasn't fitted.
I'm seriously considering it.
rgds
VS

Reply 2 of 30, by Vipersan

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Great news..
IT LIVES !!!
The components I ordered from China finally arrived..
PCB traces fixed and treated with UV solder mask laquer.
Caps replaced &
Parts fitted and powered on with crossed fingers.
Sorry for the unsteady hands with the camera..
but it proves these can be repaired
rgds
VS

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Reply 3 of 30, by Vipersan

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This build is now progressing nicely..
Gonna have to make an IO shield ..as although the case is a desktop and old ..it was made for an ITX mobo.
So far I've flashed to the last bios (patched version)
Fitted a creative SB 16 ISA card ...and the pride of my collection ..
The Voodoo 5 5500 pci graphics card.
Pentium 233 MMX
and for now at least 40mb EDO ram
plus a 3com network card
Installation of win98se went smoothly.
Added DirectX 9c
on an 80GB samsung PATA drive partitioned with 3 primarys Active C:
2x 32gb and one 12gb
The 12gb holds the 98 installation files (image) plus any drivers I might need.

On order is a 60mm fan for the CPU heatsink
and an IDE multi disc drive.
also a 9 pin usb male to female extension cord (internal) as the front usb ports I added dont reach to the mobo.
Anyone suggest anything I missed or might add to the system to improve it ?
..as this will be my default late 90s gaming PC.
Obviously I want it the best it can be.
rgds...and no I dont own a Gravis..🤣
VS

Reply 4 of 30, by jaZz_KCS

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Vipersan wrote:
This build is now progressing nicely.. Gonna have to make an IO shield ..as although the case is a desktop and old ..it was made […]
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This build is now progressing nicely..
Gonna have to make an IO shield ..as although the case is a desktop and old ..it was made for an ITX mobo.
So far I've flashed to the last bios (patched version)
Fitted a creative SB 16 ISA card ...and the pride of my collection ..
The Voodoo 5 5500 pci graphics card.
Pentium 233 MMX
and for now at least 40mb EDO ram
plus a 3com network card
Installation of win98se went smoothly.
Added DirectX 9c
on an 80GB samsung PATA drive partitioned with 3 primarys Active C:
2x 32gb and one 12gb
The 12gb holds the 98 installation files (image) plus any drivers I might need.

On order is a 60mm fan for the CPU heatsink
and an IDE multi disc drive.
also a 9 pin usb male to female extension cord (internal) as the front usb ports I added dont reach to the mobo.
Anyone suggest anything I missed or might add to the system to improve it ?
..as this will be my default late 90s gaming PC.
Obviously I want it the best it can be.
rgds...and no I dont own a Gravis..🤣
VS

5500 PCI in a 233MMX, you are a mad man 😁
You know what I have in my 233MMX? A Voodoo1

... Keep it up

Reply 5 of 30, by Vipersan

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Yep ..totally MAD JZ
What else was I gonna fit it in..
It has been sat in an anti static bag since I fixed it over 12 months ago ...and I wanted it to breath.
Overkill to the max but better than sat idle in storage.
🤣

Reply 7 of 30, by Vipersan

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A good day so far ..
Managed to grab a copy of Veritas backup exec 4.2 on ebay cheap ...which prompted me to install an adaptec scsi card in this build ..
Very useful indeed for backups of game installs as well as the various stages during the build to DAT tape.
So there's that..and an amazing days cricket where Ben stokes almost single handedly saved the Ashes 3rd test..and gave us a chance to continue.
Soon to be 'Sir' Ben stokes if there is any justice/reward
🤣

Reply 8 of 30, by Vipersan

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..Still waiting on parts for this build so to pass time I figured I'd max out the RAM ..which I read is 256mb .. (I would have liked 512 but 256 should be plently adequate for win98se)
So went digging in my mem collection and found 2 similar looking 128mb DIMM sticks ..popped out the EDO SIMMs ..and replaced them.
I also wanted to fit a 5 1/4 inch floppy drive ...but with A: as a 3.5 inch ...
I didn't have a suitable cable with 34 pin IDC after the twist ...and edge connector pre twist.
So I made one ..
The 1.2mb 5.25" drive is working fine as B: ..
I did try my spare Teac FD-55GFR 193-U as B: ..and this works fine for 1.2mb floppies ...but unlike my other drives cannot read 360k floppies...though many other brands of 1.2mb drives do ?
Tomorrow I shall pull the hard drive and image it with HDclone so I have a working and stable reference point to restore to as I start tweaking the OS.

Now I shall have to address a subject which I have been avoiding ..DOS ...
In truth I am not great with DOS ..and I want to be able to drop out of 98 into DOS and still have a working mouse ..CD..and Sound Card.
This will be a learning curve for me ..so any advice or help would be appreciated.
rgds
VS

Reply 9 of 30, by Vipersan

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Solved my reboot in DOS problem after discovering Phil had this covered already ..I found a package linked to a youtube video which includes a driver pack for mouse and CD with a PIF file which restarts in DOS and accesses Phils driver pack ..Cheers Phil.
Next turned my attention to the USB header on the motherboard..
After much frustration not getting conventional slot mounted USB ports to work I buzzed out the connections and found they aint wired as modern headers ..
Yep the use the same block of 10 pins though only nine used currently.
But although there are still 2 channels they dont run parallel E/W and are inverted N/S
The attached photo makes this clearer..so thought it worth uploading for anyone else with similar USB issues to reference.
rgds
VS

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Reply 10 of 30, by feipoa

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This board will run an AMD K6-III+ 500 MHz chip beautfully with 256 MB RAM if you know of all the quirks to making this happen. Let me know when you are interested and I can walk you through it.

Plan your life wisely, you'll be dead before you know it.

Reply 11 of 30, by Vipersan

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I'd love to try a K6- III+ buddy ....but sadly I dont own one ..and prices on fleabay have just got super expensive.
One day maybe I can get my hands on one at a price I can afford.
Anyway ..here are a couple of pix of this build (excuse the cable madness) ...
With its oversized CPU heatsink and fan ...and sporting a CD/DVD drive ...Adaptec AHA-2940 scssi controller - Archive Python DDS3 dat drive ..5.25 and 3.25 inch floppies...3com ISA PNP network card and Creative CT 2980 ISA PNP card..
Additional 2 port usb card to complement the 2 onboard ports brought out to the case front..
And the totally overkill Voodoo 5 5500..
I guess once I have the the blank I/O rear shield/plate made ..I can call it finished.
rgds
VS

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Reply 12 of 30, by feipoa

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The only place to find affordable desirable CPUs is persistence in checking CPU-World postings. It could take a year or two before you want pops up, but you'd better ready within minutes of the poster selling to claim it. It is very competitive on there. I'm slow and usually get the left-overs.

Plan your life wisely, you'll be dead before you know it.

Reply 13 of 30, by Vipersan

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There is currently a listing on fleabay for one of these :-
CPU AMD AMD-K6-III/400AHX 400MHz
Not 500mhz ...but would it be a good compromise ?...more to the point would it work in this mobo ?
and yes it is within my price range ...just..

Reply 14 of 30, by feipoa

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Yes, it should be even easier to get going at 400 MHz because you can use the 66 MHz FSB. This will allow you to use 256MB of SDRAM. For 500 MHz with a 83 MHz FSB, you must use 256 MB of FPM or EDO RAM. Though I think at 83 MHz FSB, you could still use 64 MB of SDRAM and have a stable system.

Plan your life wisely, you'll be dead before you know it.

Reply 15 of 30, by Vipersan

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So I'll grab one and fingers crossed you can help me with the upgrade..
Cheers buddy.
VS

..purchase made ..it still hurt at nearly £40 including postage...but hopefully worth the pain.
🤣

So ..when the cpu arrives I'll need to make some jumper changes feipoa
If you could kindly list those changes I need to make ..for my current 256mb sd-ram setup.
rgds

Reply 16 of 30, by feipoa

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Did you download the information I posted previously?
Re: mb-8500ttd manual needed

I have attached the Jan Steunebrink BIOS patch for Cyrix 4x, AMD K6-2, AMD K6-2+, AMD K6-III, AMD K6-III+, and 128 GB HDD support and all BIOSes I have for this board. See BIOS.txt in the zip file. When using Jan's BIOS, I recall that one or both of system/video BIOS cacheable had to be disabled. I forget which now, so test this. 

I've attached the jumper settings from the Biostar website, as well as that from Stason. I've also attached the pdf for the clock generator chip on this motherboard.

If you plan to run it with a 75 MHz or 83 MHz FSB, I have found that 256 MB of SDRAM may not be that stable. So for 75 or 83 MHz, if you insist on using SDRAM, you may need to use only 64 MB. On the other hand, I have had no problem running 256 MB of EDO 72-pin SIMMs at 83 MHz. On this board, I have not noticed any performance penalty when using EDO over SDRAM. At 83 MHz (and maybe 75 MHz?), if you are using an AMD K6-III, K6-III+, or K6-2+, you will need to disable the motherboard's L2 cache for it to run stable. But, you cannot simply disable it in the BIOS. In fact, the contrary is true - you need to leave L2 enabled in the BIOS, but must remove the DIP-28 TAG RAM chip to disable L2 cache. Some BIOS or PCB design issue? I'm not sure, but removing the TAG RAM solved the problem.

EDIT: for runnig an AMD K6-III+ at 500 MHz, you should add a small fan to the motherboard's VRM heatsink. Also, use the measured 2.02 Vcc2 jumper setting I noted in the undocumented jumper table. My system is quite stable, stable enough to run XP Pro SP3 and run all the Windows updates for days on end at 100% CPU usage. Don't forget the VRM fan though.
ATTACHMENTS
Biostar-MB-8500TTD_BIOSes.zip
(433.28 KiB) Downloaded 8 times
Biostar_MB-8500TTD_Pentium_Frequency_Generator-9169CJ-27.pdf
(557.58 KiB) Downloaded 4 times
Biostar_MB-8500TTD_Undocumented_Jumper_Table_by_Feipoa.pdf
(68.14 KiB) Downloaded 6 times
Biostar_MB-8500TTD-Manual_from_Stason.pdf
(148.09 KiB) Downloaded 7 times
Biostar_MB-8500TTD_Manual_from_Biostar_website.pdf
(121.48 KiB) Downloaded 6 times

There are no jumper settings to adjust for increase the amount of SDRAM.

Plan your life wisely, you'll be dead before you know it.

Reply 17 of 30, by Vipersan

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I did indeed grab all the zips ...in fact I used it to set up for the P233 MMX.
My cautiousness is regarding running devices out of spec..
IE overclocking anything really..
Something I have never done before on anything...and I just worry I'll somehow mess up and destroy either a mobo or a cpu ..or both.
I therefore like to reference others who have done it successfully..
I guess I'm just someone who hates taking risks..and relies on others (more used to risk taking) to prove it safe first.
There I admitted it ..
I'm either overcautious ..or a coward.
🤣

Reply 18 of 30, by feipoa

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Since you are running the FSB at 66 MHz with the AMD K6-III-400, the motherboard is not being run out of spec. Running the motherboard's FSB at 75 or 83 MHz is out of spec, but I've successfully run 83 MHz - and I don't just mean turn it on, run a benchmark, turn it off. My board ran at 500 MHz for the installation of NT4, Win98, W2K, and XP SP3. As well as running the several hundreds of updates for W2K and SP3 via the internet. It took several days of 100% CPU usage. And I also have run several games. This is how I found out that for using SDRAM, you really need to keep the FSB at 66 MHz, which you are.

The area which might be approach the spec is the motherboards CPU voltage regulators. There are heatsinks on them, but you'll want to attach a small fan. I'll send you some photos when you're at that point. I did all my previous testing without the regulator fan, so its more of a precaution to prologue their life.

While waiting for your CPU, you might want to add Jan's BIOS.

Plan your life wisely, you'll be dead before you know it.