I had some free time this evening, so I thought I'd look into a mod I was asked for: Voodoo5 5500 AGP working with 1.5v signaling (the so called AGP4x).
In the picture you have the instructions to replicate what I've come up with:

http://abload.de/thumb/v5agp4xffp9j.jpg

I only have available a motherboard with Universal AGP 2.0, but I measured the working voltage and it was 1.5v. Tested under Windows ME for a number of 3DMark2001SE runs, Fastest FSAA setting, no problems.

TESTERS NEEDED!
If some of you lads with AGP 4x only motherboards could please copy this mod on a Voodoo5 card and test for compatibility would be great. There are 3 ways to make possible the insertion of a Voodoo5 into a 4x keyed AGP slot: use an universal AGP riser, remove the notch from the motherboard slot or cut a key into the Voodoo5's PCB.
Warning: this mod converts the Voodoo5 AGP from 3.3v only operation to 1.5v signaling only. I will probably refine it over the weekend to include jumpers to select between the two modes.

Ok, I understand the pin C1 and AGP A2 modification, that's what I did too. (didn't work)

But why connect B16 directly to AGP B7? It's base clock signal (66MHz) I know, but what's the deal with it. Enlighten me please :)

Rerouting to bypass the AND gate IC that does not work with 1.5v.

Ah ok, makes sense. Thanks :) Still wondering what this gate is meant for. Many early V5 prototypes don't have it.

Test following this afternoon when I'm home from work.

You did it Komponent !
Congratulation...seems to be to easy :) after so many attempts ...

Amazing komponent! Finally you got it. Not words here.  :D

If this mod is really working, this is one of the best mods ever done! Great job komponent!!!

MOD done. Just tested kt333 board. Card boots up Vagp 1.5. Now testing 3Dmark test. System is 100% stable.

https://dl.dropboxusercontent.com/u/4383540/booting_1.5V.jpg

I would need an agp riser to test it in a pure agp4x.

Great job again komponent.

Regards,
Oscar.

:D :D :D

osckhar wrote on 31.10.13 at 16:38:29:

MOD done. Just tested kt333 board. Card boots up Vagp 1.5. Now testing 3Dmark test. System is 100% stable. I would need an agp riser to test it in a pure agp4x. Great job again komponent. Regards, Oscar.

Try to add a jumper on the A2-C1 track.
After I put a jumper there it's not working anymore.
Reinstalled the 4.7KOhm resistor in R22 and it's working again.

BTW this mod need two jumpers/microswitches to be reversible, one in the R46 the other on the C1-GND track.

@goriath,
Once you connected A2toC1 card stop to work?

Now I have connected A2toGND

Regards,
Oscar.

@goriath
Sorry, I don't understand. :o
Let aside jumpers for now. Follow exactly my instructions. It really should work.

Can confirm card is booting on AGP 2.0 board with 4x/8x notched slot. System is an Asus A8V Deluxe.

I'm using an AGP riser.

Card is NOT running stable at the moment, the system freezes on the second/third 3DMark99 test.

Going to check the AGP connection, riser cards are always a bit wobbly.

Couldn't get the card running stable in 3d applications. Flashed the bios to 1.12 but the card didn't boot anymore after this... Unfortunately I can't get it flashed back :o No matter what bios, what tool version and what system I use.

So I'm going to undo the mod and try to flash it again.

Video: http://youtu.be/73kUXgbTcG4

EDIT: VERY IMPORTANT UPDATE

http://abload.de/thumb/v5_agp4xv7r1m.jpg

For stability improvement unsolder the marked pin (pin 14 of the IC) and lift it off the pad to disable the IC (or unsolder and remove the IC).

For Windows operation compatibility improvement go to Device Manager, System Devices and locate an entry that should read "CPU to AGP controller". Select it and choose to Update Driver. Use "PCI standard PCI-to-PCI bridge" driver for it. That will disable advanced AGP features.

It is highly recommended that you apply both this updates! If you tried the mod before ad encountered problems in operation, do the above 2 things and give it another spin.

I need your feedback if you want me to further refine the mod.
Over the years I've come up with a sh1t load of world premiere mods and I've received little credit or support (I wonder why I'm still doing it?), but at least feedback is of the essence.

Glad to see you have an EPoX too.
If I stay in the motherbpoard bios for a while (3-5 minutes) the screen goes black. After RESET the system nothing change, I need to power off, unplug the power cable and uninstall the card, wait for a while, then reinstall the card, plug the power cable in and then power on again, but in the motherboard bios, if I wait enough, screen goes black again.

Could you please post the date production code of your REVA? I suspect that things differ from revision to revision.

For example weeks ago I noticed that on the REVA 2300 C1 is put to GND through 4.7KOhm resistor located in R22 position. On the REVA 2100 isn't.

@goriath: Please see the updates to the mod in the previous post and apply them.
My modded Voodoo5 5500 AGP is REV 2500. R22 is from ball C1 to VCC 3.3V and has to be removed.
Big attention when connecting A2 of the AGP connector to GND. Use a small thin wire and use the smallest possible blob of tin to solder it, but make sure you have a strong bond. I routed it to GND pad of C554. The TYPEDET pad of R22 I routed to GND pad of R9. You might experience issues due to the blob of solder on A2 altering the card proper position inside the AGP slot. Slightly altering the angle might help for better contact.

Edit: Tested on Tyan S2466N-4M and Epox 8K3A. I don't have other AGP 4x motherboards and from my less than 200 Euro monthly salary I doubt I'll invest in more.

Can you guys please post some Fotos with you modded cards ?

m14radu wrote on 02.11.13 at 16:22:49:

Can you guys please post some Fotos with you modded cards ?

I undone the mod on my 2100. After many attempts to stabilize the card, one of the two R46 pads came off and this damaged the card (no boot). The card needed a little rework to work again, but after that I left it aside since I stressed it enough :P

ASAP I will mod another card (let's see if I have a 2500 too).

BTW, I connected A2 directly to the VIA that I call C1, since it is the closer contact to the real C1 beneath the BGA (on the REVA2 infact, A2 and C1 are linked directly - btw it's the same since you have to put all to GND). C1 is the R22 pad which Komponent refers to. Then I connected C1 to GND. R22 was removed (on the 2100) since it is put to VCC3.3 (A9/B9) (while I confirm that resistor is put to GND on the 2300, so you could leave it in place I think or replace it with a 0R at most). R46 pads were been bridged together.

The card was working at 1.5V on a EPoX Ep-K5A3+ but unstable and yes, I used a thin wire and I done very flat solderings in order to not interfere with AGP pin contacts.

P.S. Would someone suggest where I could find an AGP riser of this kind in europe? --> http://www.attro.com/images/peripherals/AGP100.jpg

Don't forget to lift from the pad pin 14 of the AND gate IC or unsolder the IC. Also, for me under XP the driver change from VIA CPU to AGP controller to PCI standard PCI-to-PCI bridge was needed for the KT333 board.

m14radu wrote on 02.11.13 at 16:22:49:

Can you guys please post some Fotos with you modded cards ?

Really not much to see, courtesy of the crappy phone camera, but here you go:
http://abload.de/thumb/201311030025lkf2.jpg http://abload.de/thumb/201311039fj3h.jpg

Did some checking and on REV 1900 C1 is also only connected to VDDQ, not GND, like on 2500, through R22.

Did nobody else try the updated modd? Only basic skills required to do it...

By the way, I think the modded Voodoo5 will not work in all AGP4X motherboards, but only with those compatible with the REV A2 "AGP4x" Voodoo5 5500. The chipset has to be able to fall back to PCI66 mode. If you have a motherboard with AGP 4X only slot, but you see in BIOS a setting for AGP Mode where you can set AGP 1X, that is the one to go. AGP 1x @ 1.5v is a valid mode but not all chipsets implement it.
@Loeschzwerg: Could you please redo the updated mod (unsolder the IC) and try it on A8V motherboard? AFAIK, this one is compatible with REV A2.

Ok, got my V5 working again... damn this was quite an odyssey.

If you ever have the problem of flashing your V4/5 back and you get an error when writing the eeprom, open your bios with the tdfx bios editor, save it and DON'T rename it. Just copy it on the floppy an go ahead. If you ask me there is a very nasty bug inside the 3dfx flash tool... it does not accept names renamed under windows. Somehow it messes the checksum or something else.

Ok, back to topic... modding the card right now.

Ok, card (btw a 2300) is modded again and I also removed the quad AND gate IC.

Still not running stable on my A8V  :( I can post pictures tomorrow if someone is interested.

Loeschzwerg wrote on 05.11.13 at 21:23:15:

Ok, card (btw a 2300) is modded again and I also removed the quad AND gate IC. Still not running stable on my A8V  :( I can post pictures tomorrow if someone is interested.

Could you confirm that R22 resistor is put to GND right?

BTW I modded my 2100 again. I wired the card using wires from an ULTRA-ATA (80 conductors) ribbon flat cable. I ended with very clean work. I tested the card on the 8K5A3+ with Windows98. I suggest you Win98 since it's perfect for debugging; if there is something wrong that you should be aware of, under Win98 it will pop up. WindowsXP is too much tolerant.

The first thing to set up is AGP 1X in the bios menu, otherwise OS will hang at loading. It seems legit since the Voodoo5 is a PCI66 video adapter so set the AGP bus to 4X is perfectly useless.

Unfortunately I can confirm the card doesn't work under stable environment. If you call the driver, the card will hang as soon as the driver will call back the hardware. For example, this behaviour it's going to happen when you change video settings in the windows display property panel, or, in game (Quake3 Arena). The card hangs randomly also under 3D environment. To lift up the pin 14 of the QUAD AND gate IC and uninstall the part of the driver chipset affecting the AGP controller didn't help so much.

I started to think the card was already unstable at the beginning, so I quickly undone the modification to try it again at 3.3V but it runs fine, so I can say in normal conditions it works properly.

Why the F is my card working??? Is it something special about it?
@osckhar: Your card also worked. What REV is it?

Yes, R22 leads to ground. I will post a picture of the mod this afternoon.

AGP is at 1x, Fastwrites/Sideband OFF, AGP 3.0 Load Line Calibration OFF...
But these settings have no effect anyway, the card always behaves the same.

It runs the first 3DMark99 test and freezes either on the second or third.

OS is Win98 and I can confirm the card worked unmodded.

@komponent,when I come back at home next week I will check it. My card is 1900 date code.

Pictures:
http://abload.de/thumb/v5_agp_mod1b2l8u.jpg http://abload.de/thumb/v5_agp_mod2cnbc4.jpg http://abload.de/thumb/v5_agp_mod3mxa3p.jpg http://abload.de/thumb/v5_agp_mod49zb0v.jpg

Note: A2 to GND is not needed on AGP4x/8x slots.

1) card also freezes running at 143MHz

2) unsoldered the power mosfet (Q5) and all the parts that come with it, no effect on stability

3) tried an AGP voltage of 1.6v, no effect

Loeschzwerg wrote on 06.11.13 at 19:17:36:

Note: A2 to GND is not needed on AGP4x/8x slots. 1) card also freezes running at 143MHz 2) unsoldered the power mosfet (Q5) and all the parts that come with it, no effect on stability 3) tried an AGP voltage of 1.6v, no effect

In my case the only thing that allows the card to run at 1.5V without freezing is obviously running it in single chip mode.

Might have absolutely no relevance; my card has BIOS 1.18 on. I doubt that makes a difference (but no hurt in trying this lead too). Wish I had access to a confirmed REV A2 compatible motherboard and test it...

Tried 1.12 and 1.18, makes no difference.

Tried to save money to buy one KT400 motherboard to continue the project, but couldn't make it. Maybe next month... Damn, I wish I would have a job with a salary above 200 Euro a month!!!  >:(
Until then the status is work in progress.

komponent,

I tried the mod and card was very unstable. I used different motherboards with same problems.  It only works ok in single mode.

- Oscar.

Update:
I got myself a 1.5v AGP only for cheap, under 10 Euro. It's a ECS KM400-M2 REV1.0, so KM400 chipset. I tested my modded Voodoo5 and came to this conclusion: one or the other - there is something special about REV 2500 Voodoo5 cards, or there is something special about my card alone, as is works rock stable with 1.5v signaling (I measured VDDQ to 1.49v). Did anybody else modded a REV2500 Voodoo5? This needs more investigation...
http://abload.de/thumb/v5km400napg1.jpg

As I will not need any more to use the card with 1.5v on Universal AGP 2.0 slots, I removed the A2-GND wire. I added a 3 pin jumper to select signaling mode, 3.3v or 1.5v.
http://abload.de/thumb/201401020043xx5j.jpg
Video of 3DMark run on KM400-M2 motherboard:
http://www.youtube.com/watch?v=cbABAKMpeiY

Looks Great Komponent !

Update:
Found a Voodoo5 AGP REV 2500 in my own town to borrow and have it modded to 1.5v (AGP 4x).
Great news: tested it on KM400-M2 motherboard and it is totally stable!!! Stressed it with 4x AA, still it works with no issue.  :D
As I doubt the probability that I am so lucky to get 2 working 1.5v REV 2500 cards and the other of this kind not following suit, I guess I can state that my mod is a success at least for REV 2500 Voodoo5 5500 AGP cards.  :o
Remember, it will only be compatible with motherboards that can throttle back AGP mode to AGP 1x.
Will see if I can borrow a different REV V5 and see how it behaves when modded. Good news is that I have a compatible motherboard.  :P

Thats are great news  :D
Are there differences in the game performance between the 2x and 4x AGP settings?

MadYoshi wrote on 05.01.14 at 19:03:22:

Thats are great news  :D Are there differences in the game performance between the 2x and 4x AGP settings?

I doub't since motherboards have to "throttle back AGP mode to AGP 1x".
But it is a great news on a compatibility point of view : with this mod, you can use your V5500AGP on the least AGP motherboard if the allow 1x mod (Core 2 Duo, Athlon XP "Barton" or 64)...

just for information

v5 agp has agp_vref_1_5v and  agp_vref_3v pins connected together and to vddq. v4 4500 agp has agp_vref_3v connected to vqqd and agp_vref_1_5v connected to Vregcg, it's different voltages

@komponent,

I received different V5 AGP for mod and I take an eye V5 AGP4x MOD. I used a riser and AGP_PINA2 is connected to GND in the riser.

I use an ABIT NF7-S plus an AGP riser and tested:

V5 AGP1x REV 1900 - PERFECT 4xFSAA
V5 AGP1x REV 2100 - PERFECT 4xFSAA
V5 AGP1x REV 2300 - NOT TEST YET
V5 AGP1x REV 2500 - PERFECT 4x FSAA

3DMark2001SE 4xFSAA in looping mode and worked four hours with not lock up.

https://dl.dropboxusercontent.com/u/4383540/3Dfx/MOD_EBAY/V5_AGP4x_MOD/MOD4x_NF7-S.jpg

Now need to test a V5AGP1x REV 2300.


Quote:

just for information v5 agp has agp_vref_1_5v and  agp_vref_3v pins connected together and to vddq. v4 4500 agp has agp_vref_3v connected to vqqd and agp_vref_1_5v connected to Vregcg, it's different voltages

In V5 5500 AGP4x REV.A2 agp_vref_3v connected to VDDQ and agp_vref_1_5v connected to Vregcg same as V4 4500 AGP4x.

NOTE-  Everybody owns a V5 AGP4x REV.A2 -  if you want to boots 1.5V AGP using a motherboard with AGP UNIVERSAL. You only needs to connect AGP_PINA2 to GND card will boots using 1.5V AGP4x voltage.

Regards,
Oscar.

no need to connect a2 to gnd. all routing already exists. there is only one resistor needed to be soldered to make this card 1.5/3.3v compatible. don't remember exactly it's number but it easily can be tracked. afaik on back side, at the beginning of agp slot

same shit for powercolor v4s. only one resistor to make card 1.5/3.3 compatible

almost same shit for ordinary v5. these cards requires a bit of reworking, but they can be as compatible to 1.5v as stb v4 agp, no more, no less

Yes,  routing is already done and connecting R548 with a 0 ohms resistor or simply connecting with tin both pads is enough  for 1.5V AGP compatibility.

I did more test and REV 2300 is unstable following komponent`s step. Card lock up when FSAA is enabled.

@anthony- did you test it on 2300 revision? Do you use other way for enable AGPx4 in standar V5?

Regards,
Oscar.

komponent`s guide has major misconception concerning AND gate. it's bad idea to remove it cause it provides some sort of clock synchronization

2100 and 2300 run just fine on 4x mode in max perfomance mode

will try 4x aa mode and give feedback

Hello,

V5-5500 REV 2300 plus ABIT NF7-S Win98SE now runing stable 4xFSAA for more 1h 3DMark2001SE looping mode.

https://dl.dropboxusercontent.com/u/4383540/3Dfx/MOD_EBAY/V5_AGP4x_MOD/20161205_204709-1024x576.jpg

If anyone tried komponent's guide before but it was unstable with lock up then try this update. Feedback needed.

Regards,
Oscar.

I tested new rework on a V5 AGP 2100 REV.  since @goriath had problems using komponent's guide and with new fix it works perfect too, not lock up. It is tested as well in a V5 AGP 2500 REV.

New PICTURE looping mode V5 AGP 2300 REV runing more than 3h 4xFSAA- I guess is enough for stability prupouse.  8-)

https://dl.dropboxusercontent.com/u/4383540/3Dfx/MOD_EBAY/V5_AGP4x_MOD/looping.jpg

Regards,
Oscar.

yeah, 4x aa no problem. but looks like no one interested no more in it

btw, think between revisions on productions cards there is no difference

Correct @anthony- seems no one is intrested in such mod.  Anyway I find it very nice since to run V5 in AGP4x motherboard is very cool.  8-)

i found that on bus over 200mhz on 865 system 4x aa mode freeze system on 3dm01 in first test (there is massive texture memory swapping). switching to 1x agp mode not help much. but without aa card works fine even on 265mhz system bus

Quote:

i found that on bus over 200mhz on 865 system 4x aa mode freeze system on 3dm01 in first test (there is massive texture memory swapping). switching to 1x agp mode not help much. but without aa card works fine even on 265mhz system bus

@anthony- what motherboard are you using? I guess with your V5 A2 AGP4x over 200MHz and 4xFSAA does not lock up in same system, correct?  I only tested cards @185MHz 4xFSAA and everything correct. Setting AGP1x mode did not help?

Can you test same card in one system with AGP3.3v and 4xFSAA @200MHz? Not sure if such set up can be very stressing and hot for whole card causing too much heat and locking the card. In my O/C tests  card never reach same speed wth FSAA and not FSAA.

Anyway 200MHz is a nice speed- did you use VMod?

Regards,
Oscar.

OFF TOPIC

Received a batch for modding cards- I liked the picture.

https://dl.dropboxusercontent.com/u/4383540/3dfx/MOD_EBAY/batch_modding.jpg

Now I can test how perform V5 A2 AGP4x over 200MHz since this card at default with toshiba memory tsop dont like O/C over 185MHz.

Regards,
Oscar.