Millers Graphics
GRAM Kracker

A small box with big potential
MicroPENDIUM May, 1986

By John Koloen

Millers Graphics GRAM Kracker is an outstanding piece of hardware that offers tremendous power to TI users. This power is available to those with minimally configured systems as well as those operating out of fully expand­ed systems, though those with disk drives and expansion memories have the most potential to work with.

It is difficult to know where to begin a review of a device such as this, which provides as much programming potential as most users wilt ever develop. With it one can actually modify the computer's operating system, make changes to cartridge-based programs such as Extended BASIC, and save them. Just exactly how far one can go depends entirely on one's ability and desire. Since it's not possible to do an exhaustive review of this product in the space provided, I wilt dwell primarily on GRAM Kracker's more obvious benefits, GRAM Kracker hackers may wish to supplement this review in the future with more technically oriented text.

Performance:. GRAM Kracker is contained in a small, black enamled box that's somewhat longer than a Nayatone Widget and about an inch high. The front face includes five con­trol switches. GRAM I~acker plugs directly into the cartridge port. GRAM Kracker has its own cartridge port, so one can plug a cartridge in at any time. Unlike the console cartridge port, the OK cartridge port can be used to dump the contents of a cartridge into the GK memory and then onto a disk, RAM disk or other addressable device.

GK is available in several configura­tions, The "stripped down" unit comes with less GRAM than the fully expanded 80K GRAM Kracker. The additional GRAM costs less than $20 and is worth it. There are a number of things that cannot be done without the extra GRAM. As an example, with the 80K GRAM one can convert a Version 2.2 console into a non-V2.2 console.

This is done by loading the operating system from a non-V2.2 console into the V2.2 console. Other operating system modifications are also not possible without the 80K GRAM. For that matter, without a memory expan­sion one cannot load and save the con­sole memory, though one can save and load cartridges.

The GRAM Kracker provides two action menus, depending one what one wants to da. Its main function menu allows the user to load or save modules, initialize module space (wip­ing out the contents of memory), load and save the console contents and edit the contents of the computer's memory. Without a memory expansion users are limited to loading and saving modules and initializing module space.

Among the most common uses that many users may have for GRAM Kracker is to load the contents of a car­tridge into the GK's memory, Because GK is battery backed (the manual in-eludes thorough instructions on how to change the battery) the contents of GK memory remains intact even when the computer console is turned off. To load a different cartridge one wipes out the console memory and then loads the cartridge. All loading and saving operations are fully prompted and may be done withom referring to the manual.

The memory editor that is accessed through the first menu is quite sophisticated. This operates in a similar fashion to such disk editing programs as Disk Fixer, Disko and Disk + Aid. The difference is that in­stead of editing the contents of a disk thc memory editor allows the user to edit the coments of the computer's memory. Functions include toggling between horizontal windows, moving blocks of memory, filling a bMck of memory with a specified byte, paging up and down, searching in Hex and ASCII, toggling among colors, dump a block of mere ory to an output device, toggling between ASCII and Hex display and more.

A second menu is called up by selec­ting the load/save console option from the first menu. Here the options in­clude load console, save console, GROM/GRAM 0, GROM/GRAM 1 and GROM/GRAM 2. The GROM/GRAM selections refer to the GROM/GRAM that may be saved. As an example, this menu would be used to save the operating system and con­sole BASIC.

The GRAM Kracker is packed with a disk that includes a number of useful utilities, Among them are utilities that allow owners of the MO Explorer pro­gram to modify it so that it can "talk" to two types of GRAM (psuedo GRAM and true GRAM), a utility to load ,either the Editor/Assembler or TI-Writer from the OK very rapidly and another utility that allows E/A or TI-Writer and another cartridge to be saved together allowing the contents of two cartridges to be selected from the screen menu. Also included are a series of CALL routines, including CALL NEW, CALL BYE, CALL CLSALL, CALL CLOCK, CALL eLKOFF and CALL CAT. There are also miffties to allow the user to write BASIC pro­grams that reside in cartridge space in­stead of VDP RAM, and a couple of files containing a new character set.

All of the CALL routines are available anytime the GRAM I/racker is installed in the cartridge port. I find the CALL CAT to be the most useful. This routine allows the user to catalog disks without wiping out the contents of memory. All CALLs operate out of Extended BASIC.

Ease of Use: The GRAM Kracker is easy to install. By following the manual any user should be able to start 'using the GRAM Kracker within an hour of unpacking it. Where you go from there depends emirely on you. Documentation: The manual that comes with the GRAM [tracker is outstanding, showing the care and time that Miller Graphics puts into all its products. Its 5:5 pages are packed with information, taking the purchaser from the initial process of installing the GK to a number of tutorials on how to use it with a variety of cartridges. In­cluded are step-by-step instructions on how to give Terminal Emulator Ii the ability to operate at 1200 baud, how to modify the Tax Investment Record Keeping cartridge to access the parallel printer port, how to modify the operating system so that cartridges will automatically power up rather than having to select them from a menu, how to change the color schemes in Editor/Assembler, TI-Writer, Mini-Memory, Disk Manager II, and Ex­tended BASIC, how to chain the loading of assembly language program image files and more.

The manual also contains several pages of information about GROM and GRAM headers and other data of use to sophisticated hobbyists.

Value: I've had the GRAM Kracker plugged into my console since February and wouldn't think of disconnecting it. The only annoyances I've encountered have to do with the GROM port connection, which is com­mon to anything that i$ plugged into the GROM port. Although the GRAM Kracker fits snugly and rests on rubber feet, contact with the GROM port is occasionally lost, which locks up the computer. Apparently, the OK slides out an imperceptible distance (a micron, maybe). What I do in these cases is to press the OK toward the GROM port. I feel no movement, but the connection is remade and everything works fine. Although I have no evidence to back it up, I feel that the reduction of'wear and tear on the car­tridge port is extending the life of the console. I have had no problem plugg­ing in or removing cartridges from the GK cartridge port. (The cartridges plug into the port vertically.) When a car­tridge is plugged in, it overrides the program that may be stored in the GK. When the cartridge is removed, the program in the GK again becames resi­dent.

The most annoying problem results from the location of the GROM port. Because the GK is about an inch high, my right hand constantly rubs against it while typing on the computer. Shif­ting slightly to the left helps to reduce this but does not eliminate it.

I don't think I can speak too highly of the GRAM [tracker. It is a superb device that can open new vistas to veteran programmers and applications hounds both. (I fall in the latter category.) I have found that the more I use it (and reread the manual) the more I am able to do with it. It is money well spent.