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[required!] URL on win3x.org/uh19: http://www.win3x.org/uh19/motherboard/show/4452
Manufacturer name: Shuttle Inc (Holco)
Motherboard name: Shuttle/Holco HOT-555A
Motherboard schema:
Supported CPUs: Pentium (Socket 5, 7, MMX, from 75MHz to 200MHz), Advanced Micro Devices K5 (PR75 to PR200), Cyrix (and IBM, STMicroelectronics variants) Cx6x86/Cx6x86L (PR120 to PR166), Cyrix Cx6x8MX (including variants, from PR166 to PR266), Advanced Micro Devices K6 (from 166 to 266MHz, according to manual, although I do not think that K6 266MHz chips exist)
Photo(s) of the motherboard:
Manual(s): https://download.shuttle.eu/Archive_200 ... s/en/555a/
Motherboard BIOS(es): Award PCI/ISA PnP (fails to recognize HDDs larger than 32GB?), can be found here: https://download.shuttle.eu/Archive_2004/BIOS/555a/
Notes:
- I personally tested mine with a Intel Pentium 233 MMX (Intel S-SPEC: SL27S) unfortunately the board turned out to be unstable and would act erratically with a P233MMX CPU, I have not tested other MMX chips or other (K5/K6, Cyrix and so on) CPUs, currently running rock solid with a Pentium 133. Looking over on Internet, it seems that i am not the only one who has ran into this issue.
- This motherboard could in theory work with Microid Research's MR-BIOS for i430VX boards but unfortunately nobody seems to have found this version of MR-BIOS.
- This motherboard's VRMs (as it is a split-voltage rail board) come without heatsinks (instead the motherboard's ground plane acts as a heatsink), perhaps it could be possible to desolder the existing VRMs, mount a small VRM heatsink under them, and resolder them or ideally replace with drop-in equivalents.
- The manual mentions a SCSI BIOS built into the motherboard's BIOS, I cannot find any traces of its existence.
- I found an archive containing a whole lot of Shuttle Motherboards, the 555A seems to be among the list: https://download.shuttle.eu/Archive_2004/