Usually, the datasheet of the EEPROM will tell you what is the programming voltage. You just have to look up the chip's part number.

There is also this file on the ftp mirror, maybe it helps:

computerguy08 wrote on 2020-07-21, 13:29:

Usually, the datasheet of the EEPROM will tell you what is the programming voltage. You just have to look up the chip's part number.

I peeled away the sticker and the markings are gone, probably eaten away by the sticker's glue. I will try to see if UNIFLASH actually reports a part number for the EEPROM..

Info in that thread is incomplete.
Apparently 0101 is the only version that runs with the A4 revision of the chipset. Sucks that the only image found on the internet won't work (at least on my board).

1si4i0101.zip PVI-486SP3 A4 version chipset BIOS 0101. 
2
3si4i0202.zip PVI-486SP3 B2 & B3 chipset BIOS 0202. Note: Not for A4 version chipset. Please read README.TXT file first. 
4
5si4i0203.zip PVI-486SP3 BIOS rev. 0203. Note: 02xx BIOS can only support 497/496 B version chipset. 
6	(1) Add Intel DX4 L1 Write-back CPU Support. 
7	(2) Add IDE Prefetch Item in Chipset feature menu. 
8	(3) Fix Monochrome No display when used with PCI VGA. 
9	(4) Update NCR BIOS to 3.07.00. 
10	(5) Fix Mitsumi CD-ROM NT-Install Failed. 
11	(6) Fix Qlogic SCSI and Promise IDE Controller Init Failed. 
12	
13si4i0205.zip PVI-486SP3 BIOS rev. 0205. 
14	(1) Support Cyrix DX4 CPU. 
15	(2) Support AMD DX4-120Mhz CPU. 
16	(3) Support disable on board secondary IDE controller. 
17	
18si4i0301.zip PVI-486SP3 (SiS 496/497 B version chipset) M/B, Plug and Play BIOS rev. 0301. 
19	(1) This BIOS do not support A4 version chipset. 
20	(2) Support Cyrix M1SC/5x86 CPU. 
21	(3) Support Cyrix DX4 CPU. 
22	(4) Support AMD DX4-120Mhz CPU. 
23	(5) PVI-486SP3 M/B only support SST PH29EE010 & Winbond W29EE01 +5V Flash EPROM for PnP BIOS. 
24	
25si4i0304.zip PVI-486SP3 (SiS 496/497 B ver. chipset) M/B, Plug and Play BIOS rev. 0304. 12/05/95 
26	(1) This BIOS do not support A4 version chipset. 
27	(2) Support AMD X5 (5x86) CPU. (3) Support ESS0968 PnP card. 
28	(4) Support Cyrix M1sc (5x86) 133Mhz CPU. (5) Support NCR 860. 
29	(6) Fix Win 95 BatteryMeter present on taskbar. 
30	(7) Fix 64MB DRAM hang up problem. 
31	(8) Fix MS mouse driver 9.01 hang up problem when NO mouse attached. 
32	(9) Fix the floppy R/W problem when install the OPTi chipset PnP sound card. 
33	(10)Fix Diamond multimedia kit 8000 (OPTi) sound card hang up problem while installation. 
34	
35si4i0305.zip PVI-486SP3 (SiS 496/497 B ver. chipset) M/B, Plug and Play BIOS rev. 0305. 04/06/96 
36	(1) This BIOS do not support A4 version chipset. 
37	(2) Fix Crystal sound card hang with UMC IO. 
38	(3) Fix hang on PnP init when warmboot. 
39	(4) Fix ICU configuration error if ECP DMA disabled.
40
41si4i0306.zip PVI-486SP3 (SiS 496/497 B ver. chipset) M/B, Plug and Play BIOS rev. 0306. 07/06/96 
42	(1).Update to Award BIOS version 4.51PG. 
43	(2).Modify Int10 for Mono display.

MAME also lists this version:

1	// 5: BIOS-String: 11/23/94-SiS-496-497-PVI-4SP3-00 / #401A0-0101
2	ROM_SYSTEM_BIOS(5, "v10101", "ASUS PVI-486SP3 V1.01 #1")
3	ROMX_LOAD( "0101.bin", 0x00000, 0x20000, CRC(7862ca56) SHA1(e609585893b23db10c4ae7d2abd17cc9dda964b6), ROM_BIOS(5))

which is nowhere to be found.

More recent BIOS versions work with the A4 chipset, but are likely unstable and onboard IDE won't work.

http://gboeger.de/Computer/Asus_PVI486SP3/pvisp3-004.html lists the chipset revisions based on chip markings. Use that alongside the info above to determine which BIOSes are supported.

shock__ wrote on 2020-10-31, 22:10:

MAME also lists this version: […]
Show full quote

MAME also lists this version:

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1	// 5: BIOS-String: 11/23/94-SiS-496-497-PVI-4SP3-00 / #401A0-0101
2	ROM_SYSTEM_BIOS(5, "v10101", "ASUS PVI-486SP3 V1.01 #1")
3	ROMX_LOAD( "0101.bin", 0x00000, 0x20000, CRC(7862ca56) SHA1(e609585893b23db10c4ae7d2abd17cc9dda964b6), ROM_BIOS(5))

which is nowhere to be found.

It's probably on VOGONS somewhere, there was someone on VOGONS (not me) who had been taking PC BIOSes on VOGONS and adding them to the PC drivers in MAME - even if they weren't properly emulated.

shock__ wrote on 2020-10-31, 22:10:

MAME also lists this version: […]
Show full quote

MAME also lists this version:

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1	// 5: BIOS-String: 11/23/94-SiS-496-497-PVI-4SP3-00 / #401A0-0101
2	ROM_SYSTEM_BIOS(5, "v10101", "ASUS PVI-486SP3 V1.01 #1")
3	ROMX_LOAD( "0101.bin", 0x00000, 0x20000, CRC(7862ca56) SHA1(e609585893b23db10c4ae7d2abd17cc9dda964b6), ROM_BIOS(5))

which is nowhere to be found.

Here it is:

Added this BIOS to UH19 as well: http://www.win3x.org/uh19/motherboard/show/816

Thanks a lot! Hopefully this will safe my semi-useless 486SP3 1.2

You can use newer bios with a A4 chipset, then the integrated IDE ports won't work. You have to use an additional VLB IDE card in this case.

BastlerMike: Yup, but I wanted to use the integrated IDE port. Also the system ran incredibly unstable when using VLB graphic cards with a more modern BIOS + ISA IDE.
0101.bin works on my A4 (only briefly tested IDE + DX2 + VLB so far), SI4I0101.AWD did not.
Thanks computerguy08