|★ APPLICATIONS ★ DISQUE ★ Disc Miser ★|
|Disc Miser|The Amstrad User)||Applications Disque|
A Disc to Tape Archive Program
Have you ever wished you could safely and cheaply store away the contents of those little used discs in order to make room for new programs? Would you like to have a cheap form of backup for all your disc based programs? If the answer to either of these two questions is 'YES', then read on because here is the answer to your prayers. It's called "The Disc Miser" and it will archive an exact copy of your discs onto cassette tape.
Before I describe the workings of the program in any detail, here area few of the programs main points:
The program is NOT designed as a way to get around disc protection and of course the archived tape files will not run unless transferred back to another disc using the retrieve' option of the program.
Although the program is written in BASIC, some machine code is necessary to access the AMSDOS BIOS commands which allow us to format disc track as well as to read and write disc sectors.
The required machine code is stored in data lines 340-400 and 1405-1440 and POKEd into memory when the program is initially run. All data lines are checksummed and if, by the remotest chance, you happen to type any data incorrectly, a message will be displayed upon running the program which will tell you the line at fault.
This user-friendly approach is evident throughout the entire program since virtually every step of the operation is documented on the screen with prompts and progress messages. .
The main menu (lines 710-835) provides four options:
If the format of any track is not recognised as one of the three standard AMSTRADformats, the program is terminated and a message to that effect is displayed (lines 1450-1485).
The next step is to read the data, from each track (lines 140-220): and save it totape (lines 205-250). These tape files are headerless in order to save tape space and each is .labelled with its respective track number (line 210). The tape speed is 2500baud set by line 105.
After all tracks have been saved to tape, the program reverts to the main menu. Option 2 will allow you to retrieve your disc data later date. (After one of the kids has spilt orange cordial all over your data base disc.) Here the program reads back the disc format from tape (lines 1050-1105) and then, after prompting you for destination disc, proceeds to format each track (line 1145),read.the track data from tape (lines 1150-1160) and write the data to disc (lines 1175-1230).
As a safety feature, to protect against possible tape read errors , the previously stored track number for each block of data is matched against the track number currently being written (line 1165). If they don't match,the message "Read Error! Rewind Tape & Press any Key" is displayed and loading is stopped pending a key press (lines 1315-1325). If you rewind too far, the message "Found Track XX", is displayed (line 1320) and the program continues until the correct track is found. This means that a track is not saved to disc until the correct data is detected. After all the tracks have been transferred, the program again returns to the main menu where either option 3 (a disc catalogue) or Option 4 (terminate program) can be chosen.
The Disc Miser should be a very useful addition to your range of utilities. So. if you don't receive the monthly tape with your magazine, limber up those typing fingers and go to it.