Tomcat IV  (S1564)  Manual Rev 1.0 Addendum

This addendum for manual rev 1.0 will show the recommended memory bank configuration when using three or more banks of SIMMs.

The S1564S/D motherboard has eight SIMM sockets arranged in four banks. Each bank has two sockets and provides a 64/72-bit wide data path. SIMMs in the same bank must be the same type (EDO, parity,non-parity), size and speed. SIMMS must be installed in both sockets of a bank, and at least one bank must be filled for the motherboard to work. When populating SIMMs on multiple banks, TYAN recommends using SIMMs from the same manufacturer with the same DRAM chips, size and PCB layout. The minimum memory size is 8MB, and the maximum size is 512MB. The BIOS automatically detects memory type and size, so no jumper settings are required.

Special consideration must be taken when mixing the system board with SIMMs in three or more banks. Since banks two and three are closer to the HX chipset signal driver, those banks will have stronger signals to the SIMMs than banks zero and one. Thus ,when using an even number of banks, keep the four SIMMs of the same type in banks two and three and place the odd SIMMs in bank zero or one. For example when using four single sided SIMMs  and two double sided SIMMs, TYAN recommends placing the single sided SIMMs in banks two and three. Then place the two double sided SIMMs in either banks zero or one. This will distribute the Memory #CAS signals more evenly across the memory bus.

The following examples will show the recommended memory bank population when using three or more banks.

DS=double sided SIMMs
SS=single sided SIMMs

Bank0

Bank1

Bank2

Bank3

Total

None

DS 32Meg

SS 16Meg

SS 16Meg

128Meg

SS 16Meg

DS 32Meg

SS 16Meg

DS 32Meg

192Meg

None DS

32Meg

DS 32Meg

DS 32Meg

192Meg

Once again, please try to use SIMMs from the same manufacturer with the same memory chips and PCB layout.

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