evasive wrote on 2020-05-24, 10:14:

I'll do another once-over for my older downloads. In theory there might be a matching manual or settings sheet in there. Not all is named, some are just named sis486 or ali486, no indication of VLB/PCI whatever. I guess I need to start categorizing them, put them online and see if someone has a matching board for them. Nice little mini-project.

That would be a great project!

In the meantime, i have modified this scheme i've found on the web, and now it resembles my Motherboard: i've shopped out all the wrong stuff, i've added the missing stuff. I've tested all the pinouts shown there, even checked all traces going from the socket and the UMC chip to the pins, to modify the 'pinout' section. The 2 examples are jumper set with working settings, ( i had only 2 cpus to try at the moment) I've also mentioned the 3.3v mod.

Quite crude photoshop. But i'ts better than nothing i guess
Bus pins match, Cache matches 128k and 256k(you need a a 256 tag ram tho), voltage matches, i have 2 working setups for 2 different cpus and they both work
(these jumper settings are still bit ??? tho, i dn't really know if they'll be errors or performance slowdowns in the long run)

mongaccio wrote on 2020-05-24, 16:36:

That would be a great project! […]
Show full quote

evasive wrote on 2020-05-24, 10:14:

I'll do another once-over for my older downloads. In theory there might be a matching manual or settings sheet in there. Not all is named, some are just named sis486 or ali486, no indication of VLB/PCI whatever. I guess I need to start categorizing them, put them online and see if someone has a matching board for them. Nice little mini-project.

That would be a great project!

In the meantime, i have modified this scheme i've found on the web, and now it resembles my Motherboard: i've shopped out all the wrong stuff, i've added the missing stuff. I've tested all the pinouts shown there, even checked all traces going from the socket and the UMC chip to the pins, to modify the 'pinout' section. The 2 examples are jumper set with working settings, ( i had only 2 cpus to try at the moment) I've also mentioned the 3.3v mod.

Quite crude photoshop. But i'ts better than nothing i guess
Bus pins match, Cache matches 128k and 256k(you need a a 256 tag ram tho), voltage matches, i have 2 working setups for 2 different cpus and they both work
(these jumper settings are still bit ??? tho, i dn't really know if they'll be errors or performance slowdowns in the long run)
luckystar unknown.jpg

This looks really nice. I love it.

computerguy08 wrote on 2020-05-24, 16:45:

This looks really nice. I love it.

You should thank that G.Broers guy , he made such a neat scheme!

Just Photoshopping that and double check all the settings was a major hassle for me tho, it's years i don't use photoshop... 🤣

mongaccio wrote on 2020-05-24, 16:36:

That would be a great project! […]
Show full quote

evasive wrote on 2020-05-24, 10:14:

I'll do another once-over for my older downloads. In theory there might be a matching manual or settings sheet in there. Not all is named, some are just named sis486 or ali486, no indication of VLB/PCI whatever. I guess I need to start categorizing them, put them online and see if someone has a matching board for them. Nice little mini-project.

That would be a great project!

In the meantime, i have modified this scheme i've found on the web, and now it resembles my Motherboard: i've shopped out all the wrong stuff, i've added the missing stuff. I've tested all the pinouts shown there, even checked all traces going from the socket and the UMC chip to the pins, to modify the 'pinout' section. The 2 examples are jumper set with working settings, ( i had only 2 cpus to try at the moment) I've also mentioned the 3.3v mod.

Quite crude photoshop. But i'ts better than nothing i guess
Bus pins match, Cache matches 128k and 256k(you need a a 256 tag ram tho), voltage matches, i have 2 working setups for 2 different cpus and they both work
(these jumper settings are still bit ??? tho, i dn't really know if they'll be errors or performance slowdowns in the long run)
luckystar unknown.jpg

Hello. I recently got the same Lucky Star board. I installed a Am5x86-133 processor on it, it worked with the jumpers settings for P24D, the WB cache L1 mode is active. But there is a problem with the mouse in the games Blood, Duke Nukem 3D, Descent. The mouse does not work when using the Sound Blaster in these games. But, for example, everything is ok in the Doom.
If I disable WB cache mode (open jumper JP12 [4-5], and close JP35), then the problem disappears.
Could you check out one of these games on your WB processor (AMD DX4-120)?

beabut wrote on 2020-10-31, 19:56:

Hello. I recently got the same Lucky Star board. I installed a Am5x86-133 processor on it, it worked with the jumpers settings for P24D, the WB cache L1 mode is active. But there is a problem with the mouse in the games Blood, Duke Nukem 3D, Descent. The mouse does not work when using the Sound Blaster in these games. But, for example, everything is ok in the Doom.
If I disable WB cache mode (open jumper JP12 [4-5], and close JP35), then the problem disappears.
Could you check out one of these games on your WB processor (AMD DX4-120)?

Hello, sorry for the late answer, but i've just noticed your post. I didn't check this forum for quite a long time.

Well , your issue is really puzzling, but this motherboard is still a mystery for me.I'm glad i'm not the only one to have this kind of mobo, tho.
I'm not really sure about those jumpers and their real function.You say they are for the WB cache mode,but then why there's the BIOS option ? Do the jumper and bios settings make a conflict then?

I've tested again this motherboard: same AMD DX4, 16mb ram, CH-300 scsi/ide vlb controller, vlb video card, CUTE MOUSE mouse driver, sound blaster 16 (a pnp model, but dos drivers are great and compatible)
Microsoft home serial mouse.

Those are the jumper settings (untouched since last time)

Those are the BIOS settings

I've tested it with doom and Blood, and mouse works with both of 'em. No problems whatsoever.Heck,mouse even works in BIOS...
Good audio, good video, good controls.

The only issue i had was a glitchy unbranded mouse that i use for tests,x axis was inconsistent,i've changed it with that newer mouse and everything works flawlessly. I've played a bit of Blood's first level 😀

mongaccio wrote on 2021-02-03, 17:18:

Hello, sorry for the late answer, but i've just noticed your post. I didn't check this forum for quite a long time. […]
Show full quote

beabut wrote on 2020-10-31, 19:56:

Hello. I recently got the same Lucky Star board. I installed a Am5x86-133 processor on it, it worked with the jumpers settings for P24D, the WB cache L1 mode is active. But there is a problem with the mouse in the games Blood, Duke Nukem 3D, Descent. The mouse does not work when using the Sound Blaster in these games. But, for example, everything is ok in the Doom.
If I disable WB cache mode (open jumper JP12 [4-5], and close JP35), then the problem disappears.
Could you check out one of these games on your WB processor (AMD DX4-120)?

Hello, sorry for the late answer, but i've just noticed your post. I didn't check this forum for quite a long time.

Well , your issue is really puzzling, but this motherboard is still a mystery for me.I'm glad i'm not the only one to have this kind of mobo, tho.
I'm not really sure about those jumpers and their real function.You say they are for the WB cache mode,but then why there's the BIOS option ? Do the jumper and bios settings make a conflict then?

I've tested again this motherboard: same AMD DX4, 16mb ram, CH-300 scsi/ide vlb controller, vlb video card, CUTE MOUSE mouse driver, sound blaster 16 (a pnp model, but dos drivers are great and compatible)
Microsoft home serial mouse.

Those are the jumper settings (untouched since last time)
Immagine.jpg
Those are the BIOS settings
Immagine3.jpg
I've tested it with doom and Blood, and mouse works with both of 'em. No problems whatsoever.Heck,mouse even works in BIOS...
Good audio, good video, good controls.
Immagine2.jpg
The only issue i had was a glitchy unbranded mouse that i use for tests,x axis was inconsistent,i've changed it with that newer mouse and everything works flawlessly. I've played a bit of Blood's first level 😀

Thanks for your reply. My jumpers settings are exactly like yours, except that I soldered JP20 to enable the clock multiplier 4x for the 5x86 processor.
As for the WB option in the BIOS, this item does not affect anything at all. The caching mode is set only by jumpers.
I have already tried everything that is possible, even different BIOSes from other motherboards on the same chipset. The serial mouse still not work in these games. And in windows95, the network card also stops working if you run the Blood setup and make a sound test.
Either my board is a little faulty, or it works like this with AMD 5x86. I want to find DX4 SV8B and check with it.
Have you checked whether the L1 cache Write-Back mode is active? This can be checked using the utility CHKCPU: http://web.inter.nl.net/hcc/J.Steunebrink/ckcpu126.zip

AMD DX2-80 V8T. 3.3V

beabut wrote on 2021-02-03, 20:04:

Have you checked whether the L1 cache Write-Back mode is active? This can be checked using the utility CHKCPU

Yes I did check and it's enabled

Just to experiment a bit, I've tried to change it to write through in bios, but results enabled in write back anyway. If I disable the internal cache in bios, the program reports it.

mongaccio wrote on 2021-02-04, 09:11:

Just to experiment a bit, I've tried to change it to write through in bios, but results enabled in write back anyway. If I disable the internal cache in bios, the program reports it.

Indeed, the caching mode on this motherboard can only be switched with jumpers. You can see for yourself by removing JP12 (4-5), and close JP35. CHKCPU should show the WB mode after that.

Maybe you have AMD 5x86 to check my problem with it?

beabut wrote on 2021-02-04, 11:42:

Maybe you have AMD 5x86 to check my problem with it?

Unfortunately not, the only spare 486 i have at the moment is a 486 sx 33. But i'll try at least to fiddle with the internal cache jumpers, i'm curious to see if that program can sense if the cpu cache is set to write back or write through

Hi niki_iv,

I seem to have the exact mainboard as you do. Mine is failing to boot as well, no beeps nothing. I have dumped the bios and maybe you have done the same also? We could try and exchange them to see if that helps. The EPROM is an 27C010X. My board is also very well preserved and I would very much like to get it working. From what I've gathered so far the BIOS ID should be 2A4IB000 but I cannot find a bios file anywhere, so frustrating.

Kind regards,
G

This bios is my favourite, works well on this board.
http://vogonsdrivers.com/getfile.php?fileid=1675&menustate=0
file: 40-P301-001437-00101111-072594-DGREEN-H.BIN

Dear Sirs, I got recently a PCChips M915i motherboard . According with the info written in the motherboard (see attached picture) I can use this mobo only for DX4-SL and P24D processors.
P24D is a Intel i486DX2 Write Back but I have a 80486DX2-66 (SX911) and this Processor does not support write-back.
Can I use the this processor in this motherboard?

jnemo2004 wrote on 2023-07-11, 06:29:

Dear Sirs, I got recently a PCChips M915i motherboard . According with the info written in the motherboard (see attached picture) I can use this mobo only for DX4-SL and P24D processors.
P24D is a Intel i486DX2 Write Back but I have a 80486DX2-66 (SX911) and this Processor does not support write-back.
Can I use the this processor in this motherboard?

also, possible issue with fake cache - https://theretroweb.com/motherboards/s/pcchips-m915i