Sign In Sign-Up

Welcome!

Close

Would you like to make this site your homepage? It's fast and easy...

Yes, Please make this my home page!

No Thanks

  Don't show this to me again.

Close

• UMC 8881/8886 Chipset
• CPUs Supported
  • intel P24D, P24T, 486DX4(P24C), 486 OverDrive, 80486DX2/DX/SX/DX2-SI
  • Cyrix CX486DX4/DX2/DX/S,5x86
  • AMD DX4/DX2/AM5x86
  • UMC U5
  • TI 80486DX2
  • IBM 80486 DX2
• Supports 3.3V/3.45V/3.6V/4.0V/5V CPUs
• PCI Ver. 2.1
• Level 1 Cache in WB-Mode
• Level 2 Cache in WB-Mode
• 64/128/256/512kB, one Bank Cache Ram
• EDO DRAM Auto Support
• DRAM-Auto-Banking, up to 128 MB with two PS/2-SIMM
  of 256k, 1M, 2M, 4M, 8M, 16M, 32M, 64M
• Power Management
• 3 PCI, 4 ISA, 1 shared
• ZIF-Socket 3
• 2 IDE-Interfaces, ATA spec. Mode 0-4
• ECP/EPP parallel port
• 2 16550 compatible serial ports
• Busmaster drivers availiable
• Game port
• AMI WinBIOS (41-P103-421183-00100111-101094-486VIP)
• NCR SCSI-BIOS 3.07
• Plug and Play Flash ROM BIOS (opt.)
• Infrared port (opt.)
• PS/2 Mouse (opt.)

• The mouse port is not working. AFAIK the UMC chipset is faulty.
  So there is no way to fix it.
• There is no way to get an IrDA-Adapter. Maybe a third party-one will work, but I don't want to spent a lot of money just to find out it won't.
• The board does have a game-port connector. But the cable was missing. I connected one from another board, but it wouldn't work. I decided to disable it, and installed a cheap soundcard which already features game-port.
• I couldn't get an i486DX4/100 working.
• Lousy manual.
• I got problems with Adaptec 154x-IDE SCSI-Controller reported.
• No control over the second IDE-Port. It should activate automatic if a device is connected. Hah.
• The BIOS is not fully Y2k compliant. You'll have to correct the Year once after the 01.01.2000.
• American Megatrends list the vendor 1183 as MIRLE AUTOMATION CORPORATION. Indeed there is still a company named Mirle. If they built it or not, they do not offer any support at all. Wim's BIOS-Page lists this board as a Soyo product. I can't believe it. A dealer stated that this board was made by a company named "Flinders". Didn't find that either.
  During my research for this page, I discovered, that this board exists in several variants. Until now, I found three. All can be found on my Close Relative page.

• Very fast with an AMD5x86
• Working with 512kB 2nd-LC
• Cacheable area of 64 MB (with 512kB 2nd-LC)
  The upper 8 MB seem to be uncached.
  Maybe the caching starts again over 64 MB.
• Supports Linux and NT
• Supports up to 7.5 GB HDD. I've tested this using an 20 GB-HDD.
  The maximum values were 15Hd, 16383 Cyls and 63 Sect.
  16 Hds (giving 8.4 GB) did NOT work.
• All jumper settings are printed on board, except CPU-settings, just search.

• Why did I buy this board?
  I was running an AMD 5x86 on a Freetech board, and never thought about a replacement until it broke,
  Now I had to choose:
  1. Buy a new Pentium Board including CPU and memory for lots of money.
  2. Same for a P-II, only much more money needed.
  3. Buy a second hand PC or a board.
  4. Try to find a new 486-Board
  After fiddling around I found a dealer which had still a 486-Board to sell. Buy or leave, so I bought it. It served me well, except for the problems mentioned above. Later I got hold of another used AMD 5x86. So I returned to that dealer. Since that day I own two of those beasts. Oh, I forgot, I managed to repair my Freetech Board too. This now runs the iDX4/100 which did not work in the Syl-Boards.
• You'll have to understand that this board was produced at the very end of the 486-era. This board is very cheap made, compared to others and the lack of support should not really be a surprise.
• I checked for a BIOS-Update which may solve one or two of the problems. I couldn't locate the manufacturer, so I started looking for other BIOS-versions which may fit. For 486-Boards this is rather tricky. The boards have to be based on he same chipset and all features, even the missing ones, have to be nearly the same. Until now I've found four. Two for the M919, one for the M915 and one for the M921 . The best one is the most recent for the M919. It is also Y2K-compliant. Even Win98 works without any problems, apart for those built into Win98. The working versions are available from the Download page. Please read the infos carefully. I removed the label on the BIOS-chip only to find that the markings where painted black. With a little alcohol I cleard the surface and to my own surprise I found a SST-flash-chip!
• I upgraded to 512kB 2nd-LC using four UMC UN611014BU-15 Async Cache Chips (128kBx8). Apart from giving a slight performance increase, now up to 64 MB of RAM are cached in W/B-mode. Usually you would expect 64MB cacheable area, but maybe the chipset prevents this. Here are the test results for different RAM/Cache setups:

  Cacheable Area	256kB Cache	512 kB Cache
  2nd-LC write through	64 MB	at least 64 MB
  2nd-LC write back	32 MB	64 MB

  I can't tell, if the cacheable area is limited to 64 MB or if the memory over 64 MB is cached again. To test this I would have to install more than 64MB on my board.
  I would like to have more than four Cache sockets to install up to 1MB (maybe 2MB) of cache RAM, but due to low cost design, there are only four.
  The chipset does support this, because the PCChips M919 version 1.x, based on the same chipset (!), does offer this option.

• Bios-Setup Tips:
  This BIOS offers to detect and configure the onboard devices automatically at startup. My advise is this: Do NOT do that. Configure your devices manually. This will work reliable.
• Overclocking:
  The difference in setup between 40MHz and 33MHz is one jumper. Simply connect your Turbo-Switch to this jumper and leave the Turbo-Switch-Jumper open. You can now easily switch between both frequencies.
  The drawback is, when you boot at 40MHz, the memory bus seems to slow down to approximately 25MHz. So you end up with nothing. You'll have to start up at 33MHz and hot-boost your board, when the power is on.
  The same phenomenon is experienced with the M919, see link to the unofficial homepage below.
  Note that 40MHz is out of spec for PCI-Cards. Practice shows that VGA-Cards are usually working.
  SCSI-Cards are likely to cause trouble.
  Depending on the memory installed you may have to fiddle with the timings in the bios to get the 40MHz working. 50MHz is far too fast.
  I even tried all undocumented speed-settings. Only one (all three jumpers off) worked and set the speed to 20MHz. I suspect that the other settings did nothing or produced speeds > 40MHz.

1. Once upon a time I was dealing with my cousins PC. She has a PCChips M919 486 VIP board.
   During the search for the manufacturer I came across the Unofficial Homepage for this board.
   I liked the idea.
   Check out this page too. It offers lot of tips which are also working for the Syl8884.
2. After a while I got this board. No manufacturer, no support, nothing.
   So I decided to do such a homepage too.
3. I am convinced that 486-based PC's still have enough power to work well for lots of purposes, especially when the operating system is not Windows. Linux runs very well on those machines.

Back

20528