Purchase and Install a 64K RAM Upgrade for an Indus GT Floppy Drive (30-60 mins)

Task: Purchase and Install a 64K RAM Upgrade for an Indus GT Floppy Drive

Needed: Web Browser, Screwdriver

Time: 30-60 mins

Introduction

The Indus GT is the Cadillac of Atari 8-bit computer floppy drives. I have previously posted about some of its features and some tips for purchasing one. As I mention in that post, one of the really cool things about the GT is that it is driven by a Z80 processor. This makes it possible to use it as a Z-80 computer running the CP/M operating system. Before this can be done, the GT needs to be upgraded to 64K of RAM. Fortunately, Indus anticipated this and designed the GT with expansion pins where an expansion card with the RAM upgrade could be plugged in.

The good news for Indus GT fans is that a 64K RAM expansion card was developed by Jürgen van Radecke (thank you!) and is currently being sold in the U.S. by Gavin Haubelt (thank you!) from the Vintage Computer Center. This is a really easy install and gives Atari 8-bit users one more way to boot CP/M using the Atari as a dumb terminal. I have previously shown how to do this using the FujiNet and the DT-80 cartridge.

SRAM Charger Card
SRAM Charger Card

Instructions

This is an easy and quick installation requiring only a Phillips head screwdriver. I recommend first reading the detailed instructions provided by Jürgen which are quite good.

The first step is to purchase the SRAM Charger card from the Vintage Computer Center. They currently sell for $19.95.

The second step is to remove the case. First remove the two screws in the back of the unit and remove the plastic piece at the end. Next, flip the unit over and remove the screws on the bottom. The metal case then slides off toward the back.

Open Indus GT
Open Indus GT

The third step is to locate the expansion connector pins in the middle part of the right side of the unit (see bottom of photo below).

Indus GT Expansion Pins
Indus GT Expansion Pins

The fourth step is to plug in the SRAM Charger board with the chips on the board facing outward and away from the unit. Jürgen’s instructions warn that installing the card backwards will damage the circuits. The card should be flush with the circuit board of the GT such that no pins are visible below it (see photo below). This took some gentle pressure for mine to fit completely over the pins.

SRAM Installed in Indus GT
SRAM Installed in Indus GT

The fifth step is reassemble the case and test the drive to make sure it is still working.

Comments

This is a quick and easy install requiring no soldering. The next step is to prepare CP/M disks to see if I can start using the GT as a Z-80 computer.