Hi,
I have a new issue with a 486/VLB motherboard.
I have continous/repeat long beep and the post card display C1 BE.
It seams to be a RAM issue but i tried with many different stick of RAM that work and I have no change. I have alos changing the bios and I have the same issue. The PCB seams to be ok
There is controller for this or it is the tranceiver ? or an idea ?
Thanks for your help.
Does the board look like this : https://www.elhvb.com/webhq/models/486vlb3/sis471b.jpg
Can you take a picture of the board ??
Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun
Horun wrote on 2022-03-11, 00:09:Does the board look like this : https://www.elhvb.com/webhq/models/486vlb3/sis471b.jpg
Can you take a picture of the board ??
In attachement a picture of the motherboard.
whats with the odd number of cache chips? try disabling cache if there is a jumper for it
rasz_pl wrote on 2022-03-15, 06:15:whats with the odd number of cache chips?
They're not odd, they're regular Winbond 15ns SRAM chips: https://html.alldatasheet.com/html-pdf/47637/ … 24257AK-15.html
Ydee wrote on 2022-03-15, 09:55:rasz_pl wrote on 2022-03-15, 06:15:whats with the odd number of cache chips?
They're not odd, they're regular Winbond 15ns SRAM chips: https://html.alldatasheet.com/html-pdf/47637/ … 24257AK-15.html
count them 😀
Sorry, I didn't notice - I thought you were writing about chip marking.
You're right, a TAG chip and one cache chip are missing.
Another thing is that if 30pin modules are used, all 4 must be fitted.
Remove cache chips and reconfigure cache jampers for zero cache.
There jummed pins on main chip (right-down corner on photo and may be on left side) unjamm they. Carefully look on others such pins and chips. Install 30 pin simms all four, or use 72 pin simms one or two.
Need help? Begin with photo and model of your hardware 😉
oldgames79 wrote on 2022-03-10, 20:17:It seams to be a RAM issue but i tried with many different stick of RAM that work and I have no change.
Which RAM bank did you try? I assume the 72-pin SIMM? Your mobo most likely needs 36-bit sticks (with parity) and not the most common 32-bit ones. Not only that, the mobo (or it might be the chipset/BIOS) is rather picky about the SIMM sticks, it works well with 4MiB ones but none of my 8MiB worked properly (some did as 4MiB in the second slot if the first slot was populated with working 4MiB stick for example, but not on their own).
The 4x 30-pin bank on the other hand requires some jumpers to be set properly for it to be detected and work. Certain, but not all, mixed configurations of 30-pin and 72-pin sticks are also possible.
