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Revised 6-19-95

This application note discusses a modification of the 40-BIT PORT which now allows it to work with our new adapters for various 3.3V memory devices (DIMM, SIMM, and DRAM cards). The modification was incorporated in our production on May 9, 1995, so that all 40-BIT PORT units with serial numbers ranging from #20158 and up are already 3.3V compatible.

The new adapters for 3.3V memory devices also require the SIMCHECK program ver. 2.30 and above.


The procedure involves changing an existing 1.62K 1% precision resistor to a different value of 698 ohms. If your company does not have soldering/desoldering capability, you should sent your unit for factory upgrade as described below. INNOVENTIONS performs this modification on every unit sent for factory repair as of the date mentioned for the cutoff serial number.


To verify if the modification has been performed on a unit that has an earlier serial number, you will need to enter the DIAGNOSTIC mode of SIMCHECK and measure the voltage levels with a Volt Meter. Connect SIMCHECK and the 40-BIT PORT together, and turn SIMCHECK ON. Verify that ver. 2.30 or above is installed. From Standby Mode, press F2 to reach the initial setup menu, then F2 again to select DIAGNOSTIC. SIMCHECK will now prompt for the code for DIAGNOSTIC MODE. Enter F2, F1, F3 to enter the DIAGNOSTIC menu. With the positive lead of your Volt Meter on pin 10 of the 40-BIT PORT 72-p socket and the negative lead on pin 1, press F1 to select VOL/SPD CYCLE. The voltage levels will cycle from 6.5V, 5.5V, 5.0V, 4.5V, 3.5V, 3.3V, 3.2V, and finally to 3.0V, and should correspond to the level given on your meter within 5% accuracy. Pressing F1 will accelerate the change of one voltage level to the next. If the lower voltage levels (3.0V, 3.2V, 3.3V, and 3.5V) result with actual voltage measurements of 3.7V-4.2V, the modification has not been performed.


PARTS: One 698 ohm 1% resistor and the EPROM ver. 2.30 or higher.

TOOLS: Low wattage soldering and desoldering equipment.

Remove the four anti-skid rubber feet from the bottom of the 40-BIT PORT, and with a phillips screwdriver, remove the six screws on the enclosure. Open the 40-BIT PORT and identify the LM317 regulator (with heat sink -see illustration). Above this item are a set of four 1% resistors (blue), please identify R2 (1.62K coded: brown, blue, red, brown, brown). Carefully desolder the resistor and replace with the 698 ohm resistor (blue, white, gray, black, brown). Once complete, you may install the EPROM in your SIMCHECK in accordance to Section 5 of your Owner's Manual. After the upgrade, you must verify proper operation by performing the DIAGNOSTIC test mentioned above.

If needed, the procedure may be performed at the factory. The cost is $29.00 for the modification and an additional $29.00 should you require the SIMCHECK EPROM program. Please call our tech support department to obtain an RMA number.

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