★ APPLICATIONS ★ PROGRAMMATION ★ Memory master ★ |
| Amstrad Monitor | Applications Programmation |
Explore the Amstrad's hidden 96k memory with KEVIN EDWARDS Next comes the E command which allows memory to be edited. This can be done in two ways. The first allows you to edit byte by byte. The other option allows you to enter a string into memory. This is useful because it allows you to put messages into memory. After E has been pressed the editing type is selected by pressing either 1 or 2. Selecting 1 allows you to edit memory byte by byte. Once selected, you will be asked to enter the start location you wish to edit. Again, like all commands, the location can be entered in decimal or hexadecimal. Once this has been entered the memory location will be displayed on the screen along with its current contents. This is done first in hex and then in decimal. You will now be prompted by a question mark to enter the location's new contents - a decimal or hex number between 0 and 255 (hex &0-&FF) should be entered. After a byte has been entered the next location will be displayed in the manner previously described. Now this location can be edited. Pressing Enter without any number returns you to the monitor's command mode. This should be used to exit the editing mode. If you select editing Option 2 you are allowed to enter a string into memory. This simply puts the Ascii of each character of the string into memory in consecutive locations. As before you will be asked to enter the start location - that is, where the string will be placed in memory. Once this has been done you will be asked to ent (he string. Type it in and press Enter. The string will now be put in memory. If the string goes past the end of memory a message will indicate this and the function will be aborted. Be very careful with the editing command as it is a very powerful and "dangerous" feature of the monitor if abused. The J command allows you to call a machine code routine. When selected you will be asked to enter the location to be CALLed. After you've done this you'll be asked if you wish to continue. This is a sort of safety catch -calling a mis-typed address can cause havoc! Pressing N aborts the command while Y calls the subroutine. The L command simply returns back to Basic command mode. The final command is P. This allows the Ascii contents of memory to be printed on the screen. When selected you will be asked to enter the memory type - ROM or RAM, as with the D command. Once this has been done you must enter the start location for the operation. After it has been entered the start location is displayed in hex along with the Ascii contents of 32 locations starting from the base location given on the left. As with the D command, the function can be exited by pressing any key. The command will also be terminated if the end of memory is reached. All numbers displayed will be in hexadecimal unless otherwise stated. Any numbers entered can be in decimal or hex. As you can see, the monitor offers some extremely useful commands. You may also wish to include some commands of your own. You'll find these can be added to the program without too much difficulty. Now we've described what the program offers, let's see how it works in practice. Have a look at the following ROM locations using the D command:
Now you have a monitor you can explore the 96k of memory in the Amstrad. If you find some interesting locations write them down along with a description of what they are used for and send them to us. Happy hunting!
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