Classic Computer Magazine Archive ANTIC VOL. 7, NO. 4 / AUGUST 1988

XE-GM1 UPGRADE

The RAMdrive + XE-GM1 from Innovative Concepts is a RAM upgrade kit for the Atari XE Game System which converts this "game machine" into a powerful 128K computer that's 100% compatible with the Atari 130XE. Having 128K memory gives you access to such goodies as the RAM-resident spelling checker of Paper Clip 2.0, BASIC XE, RAMdisk support and any other software that can use the 130XE's extended RAM.

The XE-GMT kit comes with a pair of 41464 RAM chips for a full 64K, a custom IC chip, two sockets for the RAM chips, wire and a few resistors. Five pages of instructions are included as well as a useful hand-drawn schematic.

Installation requires 26 steps. They're well-documented, and I had no trouble making the upgrade – the entire installation and checkout process took about three hours.

But before you run out to buy this nifty upgrade, I must warn you that this project requires some real hardware hacking experience. Although this upgrade has only three chips, it is still a delicate process. And of course, like any hardware modification, it will void whatever Atari warranty you may have left.

The most critical step in the XE-GM1 upgrade is the removal of the original RAM chips. These must be desoldered and removed without any heat damage to the chips or circuit board. I've burned chips to death while removing them, so I was very patient during this process and I never let the chips become uncomfortably warm to the touch. After the chips were out, I carefully cleaned out and inspected the pads.

After soldering in the new RAM sockets, I did not plunge into the next process, piggybacking RAM chips. I put the original RAMs back in the computer and hooked it up, making sure not to short out anything or zap myself. I ran the self test and the original RAMs checked out. Then I shut off the XE Game System and repeated the test process on the new RAMs from the kit. They too checked out. I highly recommend these steps, in order to prevent performing an upgrade with bad RAMs.

Next the RAMs must be stacked, with pin 16 of the top chips bent out, and soldered together. Here a light, quick touch of the solder iron is recommended. Patience and plenty of cooling time between each pin are important.

Next came the custom IC, a 16-pin chip. All its legs were bent out except 8 and 16 (ground and +5 volts, respectively). This chip is soldered piggyback to U13 on the XE Game Sysytem. It looks like a squashed bug there – not pretty, but functional.

Some resistors had to be wired to some pins on the Atari's PIA chip. Another resistor had to be wired between pin 16 of the RAM chips and one pin of the custom IC. After that, it was simply a matter of stringing wire from the custom IC to the proper pins on the PIA, ANTIC, RAM and FREDDIE chips. Two pins of the FREDDIE also had to be desoldered and pulled up. I took my time, double-checking all connections and counting pin numbers three or four times before making a connection. You want this installation to work the first time.

Each time I piggybacked chips, I did something not mentioned in the instructions. I separated the upper and lower chips very slightly – 1/32 to 1/16 of an inch. This helps the chips run cooler and last longer.

Also, it took me only a couple of connections with the wire included with the kit to realize it wasn't suited for the job. The insulation had a very low melting point and tended to shrink back or melt off the wire completely during the soldering process. To prevent the risk of shorting, I switched to my own Kynar wire from Radio Shack which has a teflon insulation that withstands soldering heat.

Before putting the comnputer back together, I hooked up the motherboard and ran some preliminary checks. The upgrade ran just fine, so I buttoned up the system and ran memory tests for over 24 hours without a glich.

The package included Atari DOS 2.5 on disk, complete with utilities and RAMdisk software. On the flip side is a complete RAM test by Glenn Smith of Radon Softwaare, which detects all available RAM banks (including the 256K in my upgraded 800XL) and tests them.

If you want the classy package of the XE Game System and all the RAM power of a 130XE, then I highly recommend the XE-GM1 from Innovative Concepts. If you aren't a hardware hacking veteran, I suggest that you seek the assistance of a guru in your users group or have an Atari service center install it for you. The installation fee will be significantly less than the repair charges for burnt etch and fiberglass. – MATT RATCLIFF

$34.95. Innovative Concepts
31172 Shawn Drive
Warren, MI 48093.
(313) 293-0730