From: aa257
Subject: SUPER CARTRIDGE V4.1
Organization: Case Western Reserve Univ. Cleveland, OH (USA)
Orig-Date: Wed, 19 Nov 86 22:19:09 -0400
Date: Mon, 31 Jul 89 03:21:36 GMT


 
|--------------------------------------|
|                                      |
|This article will show you how to add |
|8k of RAM to the E/A module! Questions|
|may be directed to Ron at (419)       |
|874-1414. Later a circuit to install  |
|battery backup will be printed.This is|
|especially useful for E/A programming.|
|NO RESPONSIBILITY CAN BE TAKEN FOR ANY|
|LOSS OR DAMAGE YOU INFLICT. ATTEMPT   |
|THIS AT YOUR OWN RISK.                |
|                                      |
|Parts: Hitachi COS HM6264P-15 ($34.95)|
|      or LP-15 version ($39.95),if you|
|      want battery backup later on.   |
|                                      |
|These chips are available from JDR    |
|Micro-devices 1224 S. Bascom Ave.     |
|San Jose CA 95128 (800)538-5000       |
|                                      |
|You also need a TI game module which  |
|is foiled on both sides. Munchman was |
|used for this one. (purchased cheap)  |
|                                      |
|You will need an Edit/Assem module to |
|transplant the E/A GROM chip.         |
|A 'spare' is a good idea, in case you |
|destroy the chip! Buy a 1k resistor   |
|(R.S.# 271-023) and some wire wrap    |
|(#278-501). Vacuum solder remover -   |
|rosin core solder and a GROUNDED      |
|soldering iron (pencil type) are also |
|needed. If you don't have experience  |
|handling CMOS devices and removing    |
|solder ASK FOR HELP.                  |
|                                      |
|First unscrew the game module shell & |
|pull the case apart from the slotted  |
|side. Remove the PC board while       |
|holding the sliding door down. Note   |
|the spring is 'under' the PC board.   |
|                                      |
|Next: Unsolder and remove the GROM and|
|ROM chips. They are located as shown. |
|The ROM chip is the larger of the two.|
|--------------------------------------|
|              **************          |
|     -------  *            *          |
|    |1    28|--+-+ <--(+5v)*          |
| +++|2    27|** /     ---  *          |
| +  |3    26|  /     | G | *          |
| +  |4  H 25| Cap    | R | *          |
| +  |5  M 24|  |     | O | *          |
| +  |6  6 23| ..  .  | M | *          |
| +  |7  2 22|=!  /    ---  *      .   |
| +  |8  6 21|!! R(1K)      *      |   |
| +  |9  4 20|==/           *      R   |
| +  |10 P 19| !            *      |   |
| +  |11   18|-             *      .   |
| +  |12   17|              *          |
| +  |13   16|              *    RESET |
| +  |14   15| **************  RESISTOR|
| +   -------- *                       |
| +++++++++++++++++++                  |
|              *    +                  |
-------     ****    +            -------
FIG 3 | | | | | | | |            |
      | | | | | | | |            |
|     | | | | | | | |            |     |
|      --------------------------      |
|       1 2 3 4 5 6 7                  |
|                                      |
|--------------------------------------|
|   +5v                                |
|    |                                 |
|    |                                 |
|    O                                 |
|    OCapacitor                        |
|    O                 +5v             |
|    O                  |              |
|    |                  |              |
|     \                 O              |
|     |  AFTER          OCapacitor     |
|    oo  -----          O              |
|                       O    BEFORE    |
|                       |    ------    |
| to pin                oo GND         |
|   18                                 |
|                                      |
|Solder one end of a short piece of    |
|wire to the pad on the LEFT (where the|
|capacitor used to be) and the other   |
|end to hole 18 of the removed ROM. See|
|figure 1 below for ROM pin numbering: |
|                                      |
|                                      |
|FIG 1                                 |
|                                      |
|      ------------                    |
| NC  |1         28|VCC                |
| A12 |2  8K RAM 27|WE                 |
| A7  |3         26|CS2                |
| A6  |4         25|A8                 |
| A5  |5         24|A5                 |
| A4  |6         23|A11                |
| A3  |7         22|OE                 |
| A2  |8         21|A10                |
| A1  |9         20|CS1                |
| A0  |10        19|1/08               |
| 1/01|11        18|1/07               |
| 1/02|12        17|1/06               |
| 1/03|13        16|1/05               |
| GND |14        15|1/04               |
|      ------------                    |
|                                      |
|This will be the seventh hole from the|
|BACK of the board on the side CLOSEST |
|to the capacitor.                     |
|When a command module is inserted, it |
|normally resets the computer. If you  |
|want to disable this auto-reset in    |
|your E/A module remove the resistor at|
|the opposite end of the board. See Fig|
|3 above.                              |
|Figure 1 gives a pin diagram of the   |
|HM6264 RAM.                           |
|                                      |
|In handling the CMOS RAM chip take    |
|EXTRA precautions to eliminate static |
|electricity. Don't work on a carpet.  |
|Touch a ground before handling the    |
|device. Handle it by the plastic body.|
|Touch the pins as little as possible  |
|and work on a grounded surface, if at |
|all possible. When soldering, hold the|
|pencil iron on the pins for the LEAST |
|amount of time required to make the   |
|connection -- not more than 1 to 2    |
|seconds. If you clean the pins first, |
|it helps. Remove the RAM from its     |
|anti-static tube. Place the device on |
|its side on a table(hard flat surface)|
|and move the body of the device to    |
|very gently bend the pins to closer to|
|a right angle with respect to the     |
|body. Do both rows of pins. Check to  |
|make sure that the pins line up with  |
|the holes on the PC board. Orient the |
|chip as in figure 1 and bend RAM pins |
|1,2,20,27 & 28 straight out. This     |
|allows the chip to fit the old holes. |
|Insert the RAM into the PC board so   |
|that the notched end is flush with the|
|back of the board. RAM pin 3 goes into|
|ROM hole 1 - RAM pin 26 into ROM hole |
|24 ect. ect.                          |
|                                      |
|With the RAM in place solder in one   |
|pin on each side to hold it. Connect a|
|wire from RAM pin 27 (now bent        |
|straight out) to the Write Enable pin |
|on the edge connector. It is the third|
|from the left looking at the top of   |
|the board (see Fig 3) and it is NOT   |
|connected by foil to the PC board.    |
|Connect a wire from RAM pin 2 (also   |
|relatively easy to solder one end of  |
|the wire to RAM pin 20 but RAM pin 22 |
|is in a hole and a little more        |
|difficult to get at. Solder the wire  |
|as close to the board as possible     |
|using as little solder as feasible.   |
|Solder one lead of the 1k resistor to |
|the soldering pad just above and to   |
|the right of the ground end of the    |
|capacitor. (Refer to Fig 3) The       |
|resistor lead can be pushed through   |
|the hole. Solder the other end of the |
|resistor lead to RAM pin 20 (bent out)|
|Solder a short wire from the soldering|
|pad to the right of the +5v end of the|
|capacitor to RAM pin 28 (bent out).   |
|                                      |
|Now all that remains is to install the|
|E/A GROM. Open the E/A module and     |
|remove the PC board. Install the E/A  |
|GROM in the holes left by the old GROM|
| Notched end goes towards the back of |
|the board as well.                    |
|                                      |
|Finally solder all the IC pins in     |
|their respective pads for both the RAM|
|and GROM. Place the spring in the     |
|BOTTOM of the E/A module case. Locate |
|the sliding door properly. Put the new|
|PC board in place and snap the case   |
|closed. Replace screw and you're done.|
|                                      |
|The first thing to do is make sure    |
|your E/A GROM still works OK. Then you|
|can test out your RAM with the        |
|following program:                    |
|                                      |
|  100 INPUT 'NUMBER 0-255? ':X        |
|  110 CALL LOAD(24576)                |
|  120 CALL PEEK(24576)                |
|  130 PRINT 'MEMORY HAS ';X           |
|  140 PRINT                           |
|  150 GOTO 100                        |
|Alternatively,you can change the First|
|Free Address in High Memory (FFAH) to |
|>6000 with a CALL LOAD(8223           |
|then load 1 program w/ CALL LOAD      |
|('DSK1.NAME') as usual. If you plan to|
|load other programs,you can change the|
|FFAH to >A000 by CALL LOAD(8228       |
|I have been using the new 8k of RAM to|
|hold the DEBUG program when working on|
|assembly language programs.           |

--
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Newsgroups: comp.sys.ti,comp.sys.misc