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First post, by Marco

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Dear forum colleagues,

my chicony requires according to the manual following config for 128kb Cache:

128KB

(4) 32K x 8

NONE

(1) 8K x 8 (TAG)

I know have an offer for 4x32k plus 128Kbit TAG-Modul 28polig.

The offered Tag is larger than in the manual listed.

Question:
Is this a problem? Is more possible but without added value of course or do I need to have the exact size ?

Thank you all

1) VLSI SCAMP 311 | 386SX25@30 | 16MB | CL-GD5428 | CT2830| SCC-1 | MT32 | Fast-SCSI AHA 1542CF + BlueSCSI v2/15k U320
2) SIS486 | 486DX/2 66(@80) | 32MB | TGUI9440 | LAPC-I

Reply 1 of 7, by rmay635703

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It used to be that tag ram size determined your cachable area regardless of how much cache was installed.

Your board has an exact ratio but the only way to know for sure would
1. Determine that the larger tag has exactly the same pinout
2. Test, it’s possible that your board will just ignore the excess

Reply 2 of 7, by TheMobRules

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At least one of my 486 boards does not work with a 32K x 8 tag when configured for 128KB, so you need to test.

Reply 3 of 7, by amadeus777999

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Test it - 8k tag, the exact minimum for 128K cache, is enough but the board could play "stupid".

Reply 4 of 7, by Marco

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Ah damn and thank you all. To expensive to buy these chips if not sure enough (~30€)

Thanks - I see it’s not black and white

1) VLSI SCAMP 311 | 386SX25@30 | 16MB | CL-GD5428 | CT2830| SCC-1 | MT32 | Fast-SCSI AHA 1542CF + BlueSCSI v2/15k U320
2) SIS486 | 486DX/2 66(@80) | 32MB | TGUI9440 | LAPC-I

Reply 5 of 7, by Marco

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Hi all,

So I installed now 512 and 1024. Both sizes are being displayed correctly in the post boot screen but the system then hangs. It will in both cases only boot if external cache is disabled again.
Question now is of course whether this is due to wrong Tag ram size or due to bad Chinese iss sram modules.

Any idea how to proceed? My correct tag ram is just in shipping from overseas.

Many thanks

1) VLSI SCAMP 311 | 386SX25@30 | 16MB | CL-GD5428 | CT2830| SCC-1 | MT32 | Fast-SCSI AHA 1542CF + BlueSCSI v2/15k U320
2) SIS486 | 486DX/2 66(@80) | 32MB | TGUI9440 | LAPC-I

Reply 6 of 7, by rmay635703

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Marco wrote on 2020-08-02, 14:29:
Hi all, […]
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Hi all,

So I installed now 512 and 1024. Both sizes are being displayed correctly in the post boot screen but the system then hangs. It will in both cases only boot if external cache is disabled again.
Question now is of course whether this is due to wrong Tag ram size or due to bad Chinese iss sram modules.

Any idea how to proceed? My correct tag ram is just in shipping from overseas.

Many thanks

Without having a known working motherboard that uses the same cache and swapping chips one at a time there is no way of knowing.

My guess is the board is freaking out about the mismatched tag but you won’t likely get much from a post tester if this circumstance

Reply 7 of 7, by amadeus777999

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Marco wrote on 2020-08-02, 14:29:
Hi all, […]
Show full quote

Hi all,

So I installed now 512 and 1024. Both sizes are being displayed correctly in the post boot screen but the system then hangs. It will in both cases only boot if external cache is disabled again.
Question now is of course whether this is due to wrong Tag ram size or due to bad Chinese iss sram modules.

Any idea how to proceed? My correct tag ram is just in shipping from overseas.

Many thanks

As already said - one chip at a time with a working set can give you proof for the whole bank.
The tag can also cause a halt if the mainboard('s bios?) requires a certain minimum size(often 32k) despite it not being needed. I remember spending aeons with chinese srams on my LS486E... in and out all day - but not in a good way.