Differences

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--- blog:386_shootout_umc [2021/02/09 15:49] – [Original Auction Images] john
+++ blog:386_shootout_umc [2021/02/12 10:53] – [UMC UM82C481] john
@@ Line 4: / Line 4: @@
 A 386DX/486 motherboard acquired from an auction, with information, repairs, testing and benchmarks.
+**[Update 12/02/2021]** - The seller lost the motherboard, so this particular transaction wasn't completed.
 ===== Initial Thoughts =====
@@ Line 18: / Line 20: @@
    * The battery has leaked, but appears to be //relatively// contained
+   * **Battery leak:** on AT keyboard socket; needs to be desoldered and replaced
+   * **Battery leak:** on BIOS rom socket; needs to be desoldered and replaced, and EPROM cleaned (and backed up, preferably)
+   * **Battery leak:** around keyboard controller ; needs to be desoldered and cleaned
+   * **Battery leak:** possible evidence on first ISA slot
+   * Fitted with 4x //Winbond// W2457AK-20 SRAM chips 32kbx8 and 1x //Motorola// 8kbx8-15 tag SRAM, should be a total of 128KB of cache
+   * Soldered-on AMD 80386DX-40 processor
+   * Empty FPU socket
 ===== Motherboard Data & Variants =====
@@ Line 23: / Line 32: @@
 ^ Item           ^  ^
-| Form Factor    |  |
+| Form Factor    | Baby AT  |
-| Chipset        |  |
+| Chipset        | UMV UM82C481 / UMC82C482 |
 | Dimensions     |  |
-| Maximum RAM    |  |
+| Maximum RAM    | 8x 30pin SIMM; unknown capacity, but presumably 8x4MB to make 32MB |
-| Cache          |  |
+| Cache          | Yes; unknown capacity |
-| FPU            |  |
+| FPU            | Yes, PGA socket; 387 |
-| CPU Type       |  |
+| CPU Type       | 386 DX, PGA socket |
-| CPU Speeds     |  |
+| CPU Speeds     | 25,33,40MHz |
-| Expansion      |  |
+| Expansion      | 6x16bit, 1x8bit |
+The UMC82C481 memory controller as fitted to this board supports the provision of UMB memory via **The Last Byte** memory manager. As noted in the file //chipset.doc//:
-Motherboard jumper settings can be found in the following locations:
+> The following  chip  provides 256k of memory in eight 16k blocks
+> between C0000-DFFFF and two 64k blocks between E0000-FFFFF.
+>
+> - UM82C481 - From the UM82C480 50Mhz 80486 Chip Set
-   *
+  * {{ :blog:tlb_v220.zip |}}
+  * {{ :blog:tlb_v252.zip |}}
+These UMB regions can then be used to load drivers and TSR's high, using the //highdvr// and //hightsr// utility included with The Last Byte memory manager similar to the MS-DOS commands //devicehigh// and //loadhigh//.
 ===== Configuration =====