4000 SX (250-4900) Memory Faxback Doc. # 1524 256K SIMMS √25-5135 consists of two 256K X 9 SIMM chips at 80 nanoseconds. √25-5031 consists of four 256K x 9 SIMM chips at 100 nanoseconds. The individual chips can be ordered from Tandy National Parts under cat# 25-4900, part# MX-4089. 1MB SIMMS 25-5137 consists of two 1 MB x 9 SIMM chips at 60 nanoseconds. √25-5134 consists of two 1 MB x 9 SIMM chips at 80 nanoseconds. √25-5033 consists of two 1 MB x 9 SIMM chips at 100 nanoseconds. Memory Boards √25-4930 is a specialized 32-bit access memory expansion board for the 4000SX. This product can be ordered from Tandy National Parts under cat# 25-4930. Third Party - Memory expansion can also be accomplished by using third party, 16-bit memory adapter. These type of adapter boards do not take advantage of the on-board 32-bit memory slots of the 4000SX. √ = Discontinued Radio Shack product ┬───────────────────────────────────────────────────────────────────┐ │ Tandy 4000 SX (25-4900) Expanded from 1MB to: │ ├───────────────────────────────┬────────────────┬──────────────────┤ │ │ Add a Second │ Add to the │ │ Add to Memory Adapter │ Memory Adapter │ Second Adapter │ ├──────┬────────────────────────┼────────────────┼──────────────────┤ │ 2MB │ (4) MX-4089 │ N/A │ N/A │ ├──────┼────────────────────────┼────────────────┼──────────────────┤ │ 5MB │ (2) 25-5137 │ N/A │ N/A │ ├──────┼────────────────────────┼────────────────┼──────────────────┤ │ 8MB │ (4) 25-5137 │ N/A │ N/A │ │ │ (replace 256K chips) │ │ │ ├──────┼────────────────────────┼────────────────┼──────────────────┤ │ 12MB │ (4) 25-5137 │ 25-4930 │ (2) 25-5137 │ │ │ (replace 256K chips) │ │ │ ├──────┼────────────────────────┼────────────────┼──────────────────┤ │ 16MB │ (4) 25-5137 │ 25-4930 │ (4) 25-5137 │ │ │ (replace 256K chips) │ │ │ └──────┴────────────────────────┴────────────────┴──────────────────┘ INSTALLING ADDITIONAL MEMORY You can increase the computer's internal memory from 1M up to 16M with SIMMs. SIMMs snap into the sockets located on the high-speed local memory expansion adapter. If you are increasing the memory size to 12M or 16M, you will need to install a second high-speed local memory expansion adapter. Although the 16-bit expansion adapter slots can be used for additional memory, we recommend that you use the dedicated high-speed memory slots (expansion slots 1 and 2.) The two dedicated high-speed memory slots let you use the five 16-bit expansion adapter slots for a modem, video, and so on, while using dedicated memory at higher performance and lower costs. You can install one or more standard 16-bit expansion adapters (with 150-nanosecond or faster DRAM memory) and they will be recognized by the computer, along with memory expansion adapter one. However, if you install memory expansion adapter two, your computer will no longer recognize 16-bit memory expansion adapters in the 16-bit expansion slots. These tables show the possible memory arrangements. EXTENDED MEMORY REQUIREMENTS ┌───────────────────┬────────────┬───────────┬─────────────────────┐ │ Total │SIMM │Number │Number of Memory │ │ Memory │Type │of SIMMs │Expansion Adapters │ ├───────────────────┼────────────┼───────────┼─────────────────────┤ │ 1M │256K │4 │1 │ │ 2M │256K │8 │1 │ │ 5M │256K, 1M │8(4 of ea.)│1 │ │ 8M │1M │8 │1 │ │ 12M │1M │12 │2 │ │ 16M │1M │16 │2 │ ├───────────────────┴────────────┴───────────┴─────────────────────┤ │ Note: This computer requires 100ns or less SIMMs. │ └──────────────────────────────────────────────────────────────────┘ EXTENDED MEMORY SETTINGS ┌──────────────┬────────────────┬────────┬─────────────────────────┐ │ Total │ Bank │Memory │Jumper Settings │ │ Memory │ Assignments │Adapter │(Main Logic Bd.) │ ├──────────────┼────────────────┼────────┼─────────────────────────┤ │ 1M │ 0 & 1 (256K) │One │E30-E31, E32-E33 │ ├──────────────┼────────────────┼────────┼─────────────────────────┤ │ 2M │ 0,1,2,3 (256K) │One │E30-E31, E32-E33 │ ├──────────────┼────────────────┼────────┼─────────────────────────┤ │ 5M │ 0 & 1 (256K) │One │E30-E31, E32-E33 │ │ │ 2 & 3 (1M) │One │ │ ├──────────────┼────────────────┼────────┼─────────────────────────┤ │ 8M │ 0,1,2,3 (1M) │One │E30-E31, E32-E33 │ ├──────────────┼────────────────┼────────┼─────────────────────────┤ │ 12M │ 0,1,2,3 (1M) │One │E29-E30, E31-E32 │ │ │ 0 & 1 (1M) │Two │ │ ├──────────────┼────────────────┼────────┼─────────────────────────┤ │ 16M │ 0,1,2,3 (1M) │One │E29-E30, E31-E32 │ │ │ 0,1,2,3 (1M) │Two │ │ └──────────────┴────────────────┴────────┴─────────────────────────┘ When you add memory, be sure to: - Set the jumper on the memory expansion adapters to E1-E2 - Set the jumpers on the main logic board according to the previous table. - If you are increasing memory above 8M, set jumpers E29-E30 and E31-E32 - If necessary, carefully remove the SIMMs from their sockets as indicated in the SIMM kit installation manual. - Add the new SIMMs using the configuration listed in the previous table - Refer to your SIMM kit installation manual for more information - Run the Setupsx program on the utilities diskette to complete the installation INSTALLING AN EXPANSION ADAPTER The Tandy 4000 SX has five 16-bit slots (one of them is occupied by the VGA video expansion adapter). Use slots 3-7 for 16-bit or 8-bit expansion adapters. To install an expansion adapter, follow these steps: 1. Loosen and remove the screw at the appropriate expansion slot cover at the back of the computer. 2. Slide the metal bracket up and out of the slot. 3. With the back edge of the expansion adapter facing the back of the computer, carefully align and press the expansion adapter into the expansion slot. (Be sure the expansion adapter is fully seated.) 4. After the expansion adapter snaps into place, secure it with the retaining screw you removed in step 1. 5. Run the Setupsx utility, if necessary, to complete the installation. (/tmc-05/01/95)