32K RAM internal memory expansion for the M100/102/200 fits in your option rom space, under the cover, 100% portable! EME Systems, 2018 Parker St., Berkeley, CA 94704 EME Systems will soon release "extRAM", a 32Kbyte memory expansion for the Tandy models 100, 102 and 200. ExtRAM fits into the option ROM socket inside the expansion compartment on the back of the computer. But extRAM is read/write memory, so you can both store and retrieve data there. Its contents are immune to "cold starts" in the main RAM memory. How can you use it? EME Systems provides utility programs for different types of applications. Granted, the extRAM does not appear added to the system as 64K of generic memory, but look what it _can_ do for you. * Bank switched memory: Software "SLX", written by Portable 100 author Paul Globman, gives your M100 or M102 two totally independent RAM banks, in effect doubling its memory capacity. It works much like the 3 banks on the model 200, in which it serves as a _fourth_ bank. Each bank has its own .BA, .CO and .DO files and system areas. Programs which could not otherwise coexist can run without a hitch if they are stored in the separate banks. Switching banks takes less than 2 seconds! In practice, you load up your regular RAM with one set of files, either all at once or in the course of your work. Then you (S)ave the lot of them to extRAM by running SLX. Then you work a second set of files into RAM. When you want to switch banks, you choose the SLX (X) change option. The bank two menu appears. (X)change again, and you're back into bank one. SLX can also be called from a running BASIC program, and it can chain automatically from a program in bank one to one in bank two. * Program archive, or RAM-disk: Paul has also written extBAS, which brings some of the functionality of his cross-bank, XOS-C operating environment for the M200, to the M100/102. Under extBAS, you load up extRAM (using SLX) with the .BA and .CO programs you regularly use. You then bring them as needed into RAM to run them. You do this either from a separate menu program ( included), or from within your own programs, which can call on extBAS to chain automatically from one program to the next. Since the programs are not stored in RAM when you aren't running them, you free up a lot of room for documents or work in progress. If you have 28K worth of 4K programs, you need only reserve 4K in RAM to run them all! * Text archive: For users who need more elbow room to store burgeoning text or data (.DO) files, EME Systems provides "EXTDO". EXTDO is a set of extensions to BASIC, implemented as CALLs to the option ROM. Your .BA (or .CO) programs call upon EXTDO. The calls allow you to store and retrieve bytes, records, lines of data, or strings, and to manipulate pointers into extRAM, and to carry out file operations. EXTDO code resides in the option ROM, so you are unlikely to run into conflicts with other sofware. All but 512 bytes of the 32K in extRAM is available for your text and data file storage. * ROM emulator: Because extRAM resides in the option ROM space, it can hold programs that are designed specifically to run from there. It is just as if you had burned them into an eprom, but without the expense and trouble of an eprom burner. This is especially important in the developmental stages of a program. Owners of the RBASIC compiler or other products from King Computer Services can use the RRI utility that comes with those packages to load programs under development directly to the option ROM space, saving actual ROM burning until the very last when the code is thoroughly debugged. For purchasers of extRAM, Wilson van Alst has written ROMCOM utilities that quickly load or save an image (binary or HEX) of the entire 32K option ROM space to the COM: port, to a disk file on a desktop computer, say. You can quickly save or load option ROM programs. EME also provides INTELX.BA utilities that save or load Intel Hex format images to or from extRAM. The utility programs described above come to you in the form of BASIC listings on paper, in order to bring you extRAM at a low price. The listings are relatively short, so even with typing, you can be up and running in well under an hour with the application of your choice. Installation: ExtRAM plugs easily into the option ROM socket, after which there is one more step. You have to connect extram's jumper wires to the computer's WRITE signal and to the backup battery (Vb). Extram comes with adapters to facilitate this in the different computer models. On the 102 and 200, you tap into two pins on a RAM chip or module that sits in the expansion compartment alongside the option ROM socket. On the M100, you tap into the same two signals, but in this case on the expansion bus. Anyone with a bit of manual dexterity will be able to do it in five minutes time. No soldering or special tools are required. ExtRAM does not contain its own backup battery. Instead, it draws less than 1 microamp of standby current from the computer's internal ni-cad. This is only about 10% increase over the computer's normal standby current. EXTRAM will be available for general sale on November 1st, 1989. EME System's price for extRAM, including the instructions, adapters, and software utilities described above, will be $85 each. However, the introductory price from now through January 31st, 1990 will be $75 each. The price includes 1st class mail shipping anywhere in the US or Canada. California residents should add 6% sales tax (7% in Alameda County).