APPENDIX G. CHANGING RAM OR PROM CHIPS

The CR10 has two sockets for Random Access Memory (RAM) and one socket for Programmable Read Only Memory (PROM). The standard CR10 has 64K of RAM, (a 32K RAM chip in each socket). Earlier CR10s had 16K of RAM (an 8K RAM chip in each socket).

G.1 DISASSEMBLING THE CR10

The sockets provided for RAM and PROM are located on the CR10 CPU circuit card inside the CR10 can. To expose the RAM and PROM sockets, remove the two phillips head screws from the end opposite the connectors. Remove the end cap. The ends of two circuit cards and the RF shield will be visible (see Figure G-1). Now lay the CR10 on a flat surface, (i.e., a table), and push on the RF shield with your thumbs while grasping the can with your hands. Remove the circuit cards from the can. Orient the cards with the connector on the left and with the card that matches Figure G-2. The Central Processing Unit (CPU) is found at location H-9 and the three slots for RAM and PROM will be directly beneath it.

G.2 INSTALLING NEW RAM CHIPS IN CR10s WITH 16K RAM

The two 8K RAM chips are found at locations C-11 and C-14. With a small flat screw driver gently pry out the two 8K RAM chips at these locations and replace them with the 32K RAM chips provided in the memory upgrade. The new chips should be installed so the notched end is towards the nearest card edge. Before pushing the chips into the socket make certain that all the pins are correctly seated. After installing the 32K chips check for pins that may be bent or not firmly seated in the socket. If you notice a bent pin, remove the chip, carefully straighten it and repeat the installation procedure.

G.2.1 CHANGING JUMPERS

There are six jumpers used to configure hardware for different RAM sizes. Figure 2 shows the jumper settings for different memory configurations. A pin or small screw driver tip will work best for pulling these jumpers and relocating them as shown in Figure 2.

G.2.2 RAM TEST

Attach the CR10KD Keyboard/Display and apply power to the CR10. After the CR10 executes the RAM/PROM self test, the number 96 should be displayed in the window. The number is the sum of Kbytes in RAM (64) plus the number of Kbytes in ROM (32).

G.3 INSTALLING NEW PROM

The PROM chip is found at location C8 on the CR10 CPU board, (see Figure G-2). With a small flat screw driver, gently pry out the PROM chip and replace it with the new one. The new chip should be installed so that the notched end is towards the nearest card edge. Before pushing the chip into the socket make certain that all the pins are seating correctly. After installing the chip check for pins that may be bent or not making contact. If you notice a bent pin, remove the chip, carefully straighten it and repeat the installation procedure.

To make certain that the new chip is installed correctly enter the CR10 *B mode, (Section 1.6), and advance to the second window. This window displays the PROM signature. The five digit number in the window should match the PROM signature given with the new PROM documentation. If the numbers are different disassemble the CR10 and look for pins that are bent or not firmly seated.

G.4 INSTALLING 4K PROGRAM MEMORY PROM

Newer CR10s (shipped after 11-4-93) can be converted from the standard 2K Program Memory to 4K Program Memory by installing the correct PROM and moving a jumper. Figure G-3 shows the location and settings for the jumper. Install the PROM as described in Section G.3.

Older CR10s do not have this jumper and must be sent to Campbell Scientific for a hardware modification to 4K Program Memory.

G-1