The Gram Kracker is device sold by Miller Graphics that plugs into the cartridge port on your console. The device allows you to dump cartridges to diskette and then load those files into the Gram Kracker. This allows you to run the cartridge without physically using it. Because it is in memory it also allows you to change/modify if you want to.
The Gram Kracker could also have its memory expanded to 80K and this allows the user to save and load the TI Console GROMS into the GK as well. Not only the regular TI OS but TI BASIC as well. Like the cartridges this means you can change/modify the console GROMs too. One example would be to dump the Cassette recorder routines and add something else.
Are there any tutorials or how-tos on getting started with a Gram Kracker?
The manual can be found on the FTP server of WHTech.
We have a detailed description how to use the Gram Kracker here on ninerpedia.
Can I modify the contents in my Gram Kracker?
Yes, if you have the memory expansion. When you go into the Gram Kracker menu you will see an option 5 for editing memory. You should probably go to the WHTECH site and get the manual for the Gram Kracker on how to use the memory editor.
Can I still use cartridges with the Gram Kracker?
Yes. If you plug a cartridge into the port on the very top/back of the Gram Kracker it will be used rather than the GK memory space. If you insert a cartridge while the console is on just make sure to hit the Reset Switch.
Can I transfer Gram Kracker files into my HSGPL?
Yes. There is a transfer utility provided on the SNUG website call GKRACK and it will create an HSGPL format file from a Gram Kracker file.
When I go to load a module into the Gram Kracker I get an error "Write Protect Active", what should I do?
This error comes up when it cannot write to the either Bank 1 or Bank 2. Typically this is either because Switch 4 is not in the appropriate position (Bank 1 or Bank 2), or because a cartridge is plugged into the Gram Kracker. When a cartridge is plugged in then that cartridge is the memory space and not the Gram Kracker.
More than likely the memory space for the cartridges is corrupt. Put the fifth switch into the "Loader On" position and then reset the system. Choose "1 FOR GRAM KRACKER" at the menu. Once in there choose option 3 to "Init Module Space" and follow the instructions. This clears out the module space.
How can I tell if my Gram Kracker has the memory expansion?
The easiest method is to go into the Gram Kracker menu and if you see an option 4 and 5 then you have the memory expansion. Also you could open up the Gram Kracker and see that all the sockets have chips in them.
How come some of my Gramkracker files cannot be converted for use on the HSGPL?
One problem that was identified are with files with the Myarc Backup Bit set. The solution is to run the Myarc Backup Reset program on the GramKracker files and then do the conversion.
How do I run Plato based software with a GramKracker?
Once you have converted the Plato cartridge to disk files (with the GramKracker) you need to use a Sector Editor to search and change some code. In the Sector Editor search for occurences of "020C0F00" and replace it with "020C1000". You should find a single occurence in two difference files. That's it!
How many cartridges will the Gram Kracker hold?
The Gram Kracker will hold one cartridge in memory. I tried loading multiple cartridges but they just over-wrote each other.
I loaded Extended Basic into the Gram Kracker but when I use it my TI locks up, what should I do?
There is a problem with running Extended Basic and if you have Switch 4 in either the "Bank 1" or "Bank 2" position. Memory has to be write protected so make sure this switch is in the "W/P" position.
Note: I confirmed this error with my Gram Kracker. I also have a Rave99 Keyboard adapter and my console groms loaded into the GK. My keyboard would not work properly after this error. If you run into this error you should reset and reload your Gram Kracker because I think the memory space gets corrupted.
I loaded my Gram Kracker but when I come back later it is empty, what is wrong?
The Gram Kracker has a battery that provides low power to keep the data in memory. More than likely your batttery is dead. Take off all the screws on the outside of the case and it will come apart. You should see the battery in there and you can simply replace it.
If I edit the contents of memory in my Gram Kracker can I save it so I don't lose it?
Yes, and you should. If the battery goes dead or anything else corrupts the memory space then you want to have something you can quickly reload.
The same process that you use to save modules or console GROMs can be followed. For cartridges just don't plug in a cartridge and that way it will take it from the Gram Kracker. For console GROMs, keep Switches 2 or 3 in the "Gram 0" and "Gram 1-2" positions and it will take it from there.
What can be done with editing the memory space of modules or GROMs?
Anything. In short you could completely re-write a program or make modifications to existing ones. For example, Extended Basic has an auto-load feature that spends a couple of seconds search DSK1 for a program with the name "LOAD". If this is annoying you could disable that feature.
There is document on WHTECH that is about 36 pages long and has some great examples of things done with a Gram Kracker. You can find a copy at the following location:
Thanks to Ernie Pergrem for pointing this out!
What do the switches on the Gram Kracker do?
Switch 1: GK OFF / Normal / Reset This is a simple one. The switch will only rest in the Normal or the GK OFF position. It will not sit in the Reset postion. If you want to use the GK then leave it in the Normal position. If you want to disable the GK then put it in the GK OFF position. If at any time you want to Reset your TI, just press it down and let go.
Switch 2: Gram 0 / OpSys This switch is tell the TI to either load either the internal TI GROMS (OpSys) or to load the GROMS stored in the GK (Gram 0). NOTE: If your GK does not have the memory installed or you have not loaded Gram 0 with data then your TI won't start properly if it is in the Gram 0 position.
Switch 3: Gram 1-2 / TI Basic This switch is to tell the TI to either load the internal console Basic (TI Basic) or to load the GROMS stored in the GK (Gram 1-2). OTE: If your GK does not have the memory installed or you have not loaded Gram 0 with data then your TI won't start properly if it is in the Gram 0 position.
Switch 4: Bank 1 / "W/P" / Bank 2 This is the WriteProtect switch for the GK. It is used to make either Bank 1 or Bank 2 of the memory writeable. If it is in the W/P position then they are not writeable. You use this switch when you want to load something into the GK.
Switch 5: Loader On / Loader Off When you turn on the TI with the GK installed you will come to the choice menu. With the GK is in "Loader On" position then you will see Gram Kracker as option 1 in the menu. If the GK is in the "Loader Off" position then you will see TI Basic as option 1. If you are working with the GK to change it or save modules then you want it on. If you are just using your TI then you want it off.
Are the file formats for the PGram+ card and the MG GramKracker the same?
Yes, they are the same. One thing to note is that the MG GramKracker files have extra RAM to override the console GROMS which can't be done on the PGRAM+.