TheMobRules wrote on 2021-08-10, 06:11:
There doesn't seem to be a lot of info about that board online. Annoyingly, the TH99 page lists them as "32-bit local bus cards (2)" without providing any further details.
However, this blog post from 2009 mentions that board and claims to be using a VLB video card and I/O controller... not sure if that's enough evidence for you as the cards are not entirely visible from the pictures, so it's difficult to tell whether they're actually VLB or some other special local bus.
Right. I went through that blog post, but it's not clear if he got the VLB WD card to work. He's using an ISA ET4000AX video card in his setup. Also the I/O controller may have come w/ the motherboard, if using a proprietary bus.
PC Hoarder Patrol wrote on 2021-08-10, 06:30:The Giga-Byte archive from 1977 mentions the GA-486SA as an SiS EISA rather than Opti local bus board... […]
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The Giga-Byte archive from 1977 mentions the GA-486SA as an SiS EISA rather than Opti local bus board...
"SIS.ZIP ECU for GA-486SA/TA EISA configuration utility for 486SA/TA "
This seems to be that EISA config utility (ECU) for the same
motherboard_driver_ecu_other_sis.zip
Not sure EISA + VLB is all that rare - I have an ECS board (SL-486VE) which seems to be based on the same SiS chipset as yours, and still with its original working Dallas as well 😀
ECS SL-486VE.JPG
Sick! I'd love to try out that utility, but don't have any EISA cards atm. Tho I'm sure another Vogoner has.
Epic find! Have you tried the VLB slots yet? Another member mentioned that some ECS boards had VLB-lookalike slots: same physical connector, but not pin-compatible.
Yours also supports 128mb. Must've been a very high-end SIS chipset.
mkarcher wrote on 2021-08-10, 07:23:
I've also seen ALi chipset based 486 boards that support 128MB with 30-pin SIMMs, but I didn't yet enter the game of acquiring the required 16MB 30-pin SIMMs.
If you have a continuity tester, you might want to test address/data pins from the suspected VL slot connectors to the corresponding processor pins. Likely there are no buffer chips between the local bus slot and the processor on this board. If data and address lines match up, the slots are likely VL slots.
For the record, I got 16mb 30-pin SIMMs to work on an OPTI-based 386 board (64mb total). Probably not allowed to post Ebay link, but they're the modules w/ 2 rows of chips: 5 on the top and 4 on the bottom, with parity.
Will consider getting a continuity tester, vs. possibly getting a junk Trident VLB card to test.
dionb wrote on 2021-08-10, 10:36:
Rule of thumb: a board with EISA-like slots with 4 or more of those slots is almost certain to be EISA, as truly local bus (OPTi etc) never supported more than three slots.
Tbh, I'd be more concerned about the apparent VLB slots here than the EISA: VLB+EISA was rare, and one of the vendors doing it was ECS - but ECS had its own proprietary local bus, using the same physical form factor as VLB, just with different pinout (including power/ground pins!). However this is a Gigabyte board and never heard of them using ECS local bus instead of VESA.
I would take anything on that TH99 page with a very big pinch of salt given absence of EISA info and the listing of OPTi chipset where it's clearly SiS...
Great to know! Looks like PC Hoarder Patrol and I have "EISA winners"... not to be confused w/ ELSA Winners 🤣
Exactly. I'm concerned that my board has those ECS or similar "fake VLB" slots that'll take a card, only to fry it on the spot. That was the case w/ the FX-3000's, which another thread mentioned had the ECS slots. Not likely on a Gigabyte board, but my VLB Mach32 is still too much to risk.
Will probably just test w/ a cheap Trident 9200. Had one at some point and it was no better than a good ISA card 🤣
Disruptor wrote on 2021-08-10, 12:10:So the only thing that should prevent you from testing your VLB graphics card is the external clock speed.
Which processor do yo […]
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So the only thing that should prevent you from testing your VLB graphics card is the external clock speed.
Which processor do you use and how fast is it clocked?
However, you need to run an ECU (EISA configuration utility) tool to get rid of EISA error messages, if you have - to configure your board.
I'm a bit jealous now 😉
It's currently running a 486SX-25 but I'd really like to build a DX2-80 out of it. If the board (or rather, its VLB implementation) won't take 40mhz clock, I'll probably just swap it w/ my PCChips M912 since that + Mach32 works at 40mhz.
So maybe, just maybe, another EISA + VLB mobo will pop up on Ebay😝
Does anyone know if early VLB boards can work at 40mhz bus speeds? Whether this one actually has VLB, it doesn't have anything like "VESA wait state" jumpers. Also, there's no clockgen chip; I'd have to buy a crystal to run at 40.