What is CL- and CL+? \ VOGONS

What is CL- and CL+?

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First post, by eesz34

Posted on 2022-12-13, 19:14

eesz34 Offline

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I recently got a 486 board with a UMC 82C481 chipset and L2 cache and wanted to try MR BIOS on it. In looking at the MR BIOS bundle, I first tried the one listed as:

UMC_UM82C481BF UMC UM82C481BF 1.44

and it works, but it appears to leave external cache disabled with no way to change it in the setup. Looking at other files for this chipset there's:

V002B406 OPTi WriteThru 82C481 - 486 WriteThru 1.65
V002B408 OPTi WriteThru 82C481 - 486 WriteThru (CL-) 1.65
V002B409 OPTi WriteThru 82C481 - 486 WriteThru (CL+) 1.65

I'm thinking perhaps the three above enable cache because of their description. V002B406 is half the size of the others, and the original AMIBIOS, so I'm going to ignore that one. But what is CL- and CL+? Is it CAS Latency?

Reply 1 of 4, by maxtherabbit

Posted on 2022-12-13, 21:36

maxtherabbit Offline

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It has something to do with the turbo LED

Reply 2 of 4, by eesz34

Posted on 2022-12-13, 22:16

eesz34 Offline

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maxtherabbit wrote on 2022-12-13, 21:36:

It has something to do with the turbo LED

Really? I've searched high and low and can't find anything on this.

Does anyone know what this is?

Reply 3 of 4, by maxtherabbit

Posted on 2022-12-13, 23:51

maxtherabbit Offline

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1-----------------------------------------------------------------
2 8042 Turbo/Turbo-LED control:  (T-) (T+) (TL-) (TL+) (CL-) (CL+)
3-----------------------------------------------------------------
4
5Hot-Key TURBO and/or LED control via keystrokes  <CTRL> <ALT> <-/+>  will
6simultaneously activate all commonly used 8042 pins: 23,24, 27,28,29,30.
7
8The system board layout must connect one of these pins to an existing
9Turbo/LED circuit.  Consideration should be given to the remaining pins
10which are also driven.  MR BIOS (r) 8042 or AMI KF keyboard controller
11may be used for this purpose.  Award, Phoenix, and Quadtel 8042's cannot
12be used with any MR BIOS (r) version designated as having this special
138042 functionality.
14
15                  Active
16Legend  Function  State   Description
17------  --------  -----   -------------------------------------------- 
18(T-)    Turbo      Low    8042 turbo/LED circuit ONLY (no chipset register
19(T+)    Turbo      High   turbo).  Also, Setup Utility SPEED screen appears.
20
21(TL-)   Turbo-LED  Low    Both chipset turbo and 8042 pins are activated.
22(TL+)   Turbo-LED  High
23
24(CL-)   Cache-LED  Low    Used mainly with 486, Cache state indicates "turbo".
25(CL+)   Cache-LED  High

Reply 4 of 4, by eesz34

Posted on 2022-12-14, 03:55

eesz34 Offline

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maxtherabbit wrote on 2022-12-13, 23:51:

[…]
Show full quote

1-----------------------------------------------------------------
2 8042 Turbo/Turbo-LED control:  (T-) (T+) (TL-) (TL+) (CL-) (CL+)
3-----------------------------------------------------------------
4
5Hot-Key TURBO and/or LED control via keystrokes  <CTRL> <ALT> <-/+>  will
6simultaneously activate all commonly used 8042 pins: 23,24, 27,28,29,30.
7
8The system board layout must connect one of these pins to an existing
9Turbo/LED circuit.  Consideration should be given to the remaining pins
10which are also driven.  MR BIOS (r) 8042 or AMI KF keyboard controller
11may be used for this purpose.  Award, Phoenix, and Quadtel 8042's cannot
12be used with any MR BIOS (r) version designated as having this special
138042 functionality.
14
15                  Active
16Legend  Function  State   Description
17------  --------  -----   -------------------------------------------- 
18(T-)    Turbo      Low    8042 turbo/LED circuit ONLY (no chipset register
19(T+)    Turbo      High   turbo).  Also, Setup Utility SPEED screen appears.
20
21(TL-)   Turbo-LED  Low    Both chipset turbo and 8042 pins are activated.
22(TL+)   Turbo-LED  High
23
24(CL-)   Cache-LED  Low    Used mainly with 486, Cache state indicates "turbo".
25(CL+)   Cache-LED  High

Nice, thank you.

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