Disc Editor documentation, 2 versions. DISC EDITOR DOCUMENTATION (REV. 1.0) The Disc Editor Software is intended to allow the user to edit a standard T.I. 99/4a disc on sector by sector basis. In addition to the T.I. disc controller, it will also work with the MYARC controller and the MYARC Ramdisc. No attempt is made in this documentation to explain the layout of the sectors on a disc, or to explain the data contained therein, as this information has been (or will be) published elsewhere. However, an example of how to find a file on the disc is given at the end. ****** WARNING ****** In order to prevent accidental writing to a disc, much of the software is concerned with checking that the system is functional, and is of the correct environment. It attempts to ensure that such things as hardware single steppers or software interpreters (such as EXPLORER) are not present, as reading and writing to a disc are time critical functions and must not be interfered with. If any of these fuctions are detected, they will be either locked out so that the software can function correctly, or if they cannot be locked out, the CPU will be locked up after the initial header appears on the screen. Attempts to over-ride these features by modifying the ROM in the module WILL result in unpredictable and usually catastrophic results. Note that the ROM in the module cannot be emulated by such things as Miller's Gram Cracker. SET-UP REQUIRED 1. TI 99/4A Console 2. Disc controller 3. 32k memory expansion 4. Disc Editor module. Insert module, switch on disc controller, memory expansion and console. Press any key as usual, then select the Disc Editor from the Menu. If the software considers the environment correct, then after the header appears on the screen, the Copyright line will appear at the bottom and a request for the Drive number to be input will appear below the header. Enter the drive number (or use enter if it is displayed already), and a request for the Sector number will appear. The input required here is a HEXADECIMAL number (this is because the Sector numbers held on the disc are in HEX) but note that no checking is done to see if the number is a valid sector number for the disc - an out of range number will result in an error code (usually 07) from the DSR in the disk controller. (See also note on errors later). When entering the sector number, full edit facilities are allowed (ie INSERT, DELETE etc), and leading zeros are not required, but to read sector zero, a zero (0) must be entered. The 'BACK' key is enabled at this point, and pressing it will result in a request for the drive number again. KEY FUNCTIONS WHILST IN EDIT MODE FUNCTION 1 Display sector in Hexadecimal FUNCTION 2 Display sector in ASCII FUNCTION 3 Save sector to RAM FUNCTION 4 Display previous sector FUNCTION 5 Select new sector/disc FUNCTION 6 Display next sector FUNCTION 7 Write saved sector FUNCTION 8 Re-write present sector FUNCTION 9 Not used FUNCTION = Quit Having entered the Sector number, press enter and the sector will be displayed in ASCII, with 14 characters per line and the cursor at the top left-hand corner of the sector data. The data can then be edited in ASCII, none ASCII characters may be accepted by the editor (such as Function 0 (>BC)), but only if they are not the recognised Edit function keys. If it is required to Edit the sector in HEX, then press Function 1, and the display will appear in HEX, permitting each nibble to be edited. To revert to ASCII mode, press Funtion 2 - the mode is remembered when changing sectors or drives. As the screen is presented as 14 bytes per line, it is difficult to find out where a particular byte is on the screen, and so a continuously updated cursor address is given on the bottom line of the screen to assist with this. Any data in the sector may be edited, and will NOT be written back to the disc UNLESS specifically requested by pressing Function 8. When Function 8 is pressed, the 'accept' tone is given, and the bottom line will contain the message 'REWRITE THE SECTOR (Y/N)?'. Any input at this point other than 'Y' or 'y' will abort the re-write command, thereby giving protection against accidental writing to the disc. The next sector can be displayed by pressing Function 6, and the previous sector by pressing Funtion 4. Access to a different Drive or Sector can be obtained by pressing Function 5 - the present Drive number is remembered and so 'Enter' is normally only required for this, the sector number is always cleared as it has been found that leaving the previous data there results in confusion. At any time whilst editing a sector, the sector data (as displayed on the screen) can be saved to RAM, and at a later date, the saved data can be written to the disc (to any sector). This feature permits such things as moving single sectors from one disc to another, moving mixed up directories and rescuing discs with a bad sector 0 by copying sector 0 from another disc. The sector data is saved to RAM by pressing Function 3, the indication that the command has been accepted is given by the 'accept' tone. The saved data can be written to the disc at any sector location by displaying (or attempting to display) the appropriate sector and then pressing Function 7. When the key is pressed, the message 'WRITE SAVED SECTOR (Y/N)? will appear on the bottom line, and again, anything but an affirmative answer will result in the command being aborted. ERROR REPORTING. Error reporting is as given in the Editor Assembler Manual for Assembly Language programs, with the exception that an error ending in 'E' or 'F' indicates that the called device service routine was not found (this is usually because the Disc controller is not present or is switched off). NOTE * NOTE * NOTE If an error is reported when trying to access a sector on the disc, then the data displayed on the screen will not be that which appears on the sector requested (though it may be part of it). Usually the data on the screen when a key is pressed for restart will be what was previously in VRAM from the last sector access, although if a sector is partially read, then the data which was read successfully will appear along with some previous data. EXAMPLE OF LOCATING A FILE ON THE DISC. Read sector 2 in ASCII mode, the file name of which this is the directory will appear in the first 10 bytes. If this is not the file you want to find, then press 'Next Sector' until the correct file name is found. On the third line down in the sector data take the first four bytes. Three of these bytes give the sector number at which the file starts. The bytes are arranged as B C X A where the sector number is A B C. For instance if the first four bytes are A421 then the sector number is 1A4. Press Function five, then 'Enter' then the sector number as required and the sector displayed is the first sector of the appropriate file. ********** Whilst every care has been taken in the writing of the software, the author does not guarantee that there is not some bug lurking in it which will destroy data on a disc (though it has been thoroughly tested by various people). Accordingly, when using the Disc Editor, it is up to the user to ensure that no attempt is made to edit a disc which contains non-reproducable data which may be destroyed. If any 'bugs' are found, or you have any suggestions or comments, then please communicate them to: Colin Hinson 119 High Street Blunham Beds. <19> DISC EDITOR DOCUMENTATION (REV. 1.0) The Disc Editor Software is intended to allow the user to edit a standard T.I. 99/4a disc on sector by sector basis. In addition to the T.I. disc controller, it will also work with the MYARC controller and the MYARC Ramdisc. No attempt is made in this documentation to explain the layout of the sectors on a disc, or to explain the data contained therein, as this information has been (or will be) published elsewhere. ****** WARNING ****** In order to prevent accidental (unintended) writing to a disc, much of the software is concerned with checking that the system is functional, and is of the correct environment. It attempts to ensure that such things as hardware single steppers or software interpreters (such as EXPLORER) are not present, as reading and writing to a disc are time critical functions and must not be interfered with. If any of these fuctions are detected, they will be either locked out so that the software can function correctly, or if they cannot be locked out, the CPU will be locked up after the initial header appears on the screen. Attempts to over-ride these features by modifying the ROM in the module WILL result in unpredictable and usually catastrophic results. KEY FUNCTIONS WHILST IN EDIT MODE FUNCTION 1 Display sector in Hexadecimal FUNCTION 2 Display sector in ASCII FUNCTION 3 Save sector to RAM FUNCTION 4 Display previous sector FUNCTION 5 Select new sector/disc FUNCTION 6 Display next sector FUNCTION 7 Write saved sector FUNCTION 8 Re-write present sector FUNCTION 9 Not used FUNCTION = Quit SET-UP REQUIRED 1. TI 99/4A Console 2. Disc controller 3. 32k memory expansion 4. Disc Editor module. Insert module, switch on disc controller, memory expansion and console. Press any key as usual, then select the Disc Editor from the Menu. If the software considers the environment correct, then after the header appears on the screen, the Copyright line will appear at the bottom and a request for the Drive number to be input will appear below the header. Enter the drive number (or use enter if it is displayed already), and a request for the Sector number will appear. The input required here is a HEXADECIMAL number (this is because the Sector numbers held on the disc are in HEX) but note that no checking is done to see if the number is a valid sector number for the disc - an out of range number will result in an error code (usually 07) from the DSR in the disk controller. (See also note on errors later). When entering the sector number, full edit facilities are allowed (ie INSERT, DELETE etc), and leading zeros are not required, but to read sector zero, a zero (0) must be entered. The 'BACK' key is enabled at this point, and pressing it will result in a request for the drive number again. Having entered the Sector number, press enter and the sector will be displayed in ASCII, with 14 characters per line and the cursor at the top right-hand corner of the sector data. The data can then be edited in ASCII, none ASCII characters may be accepted by the editor (such as Function 0 (>BC)), but only if they are not the recognised Edit function keys. If it is required to Edit the sector in HEX, then press Function 1, and the display will appear in HEX, permitting each nibble to be edited. To revert to ASCII mode, press Funtion 2 - the mode is remembered when changing sectors or drives. As the screen is presented as 14 bytes per line, it is difficult to find out where a particular byte is on the screen, and so a continuously updated cursor address is given on the bottom line of the screen to assist with this. Any data in the sector may be edited, and will NOT be written back to the disc UNLESS specifically requested by pressing Function 8. When Function 8 is pressed, the 'accept' tone is given, and the bottom line will contain the message 'REWRITE THE SECTOR (Y/N)?'. Any input at this point other than 'Y' or 'y' will abort the re-write command, thereby giving protection against accidental writing to the disc. The next sector can be displayed by pressing Function 6, and the previous sector by pressing Funtion 4. Access to a different Drive or Sector can be obtained by pressing Function 5 - the present Drive number is remembered and so 'Enter' is normally only required for this, the sector number is always cleared as it has been found that leaving the previous data there results in confusion. At any time whilst editing a sector, the sector data can be saved to RAM, and at a later date, the saved data can be written to the disc (to any sector). This feature permits such things as moving single sectors from one disc to another, moving mixed up directories and rescuing discs with a bad sector 0 by copying sector 0 from another disc. The sector data is saved to RAM by pressing Function 3, the indication that the command has been accepted is given by the 'accept' tone. The saved data can be written to the disc at any sector location by displaying (or attempting to display) the appropriate sector and then pressing Function 7. When the key is pressed, the message 'WRITE SAVED SECTOR (Y/N)? will appear on the bottom line, and again, anything but an affirmative answer will result in the command being aborted. <18><\0><\0><\0><\0><\0><\0><\0><\0><\0><\0><\0><\0><\0><\0><\0><\0> DISC EDITOR DOCUMENTATION (REV. 1.0) The Disc Editor Software is intended to allow the user to edit a standard T.I. 99/4a disc on sector by sector basis. In addition to the T.I. disc controller, it will also work with the MYARC controller and the MYARC Ramdisc. No attempt is made in this documentation to explain the layout of the sectors on a disc, or to explain the data contained therein, as this information has been (or will be) published elsewhere. However, an example of how to find a file on the disc is given at the end. ****** WARNING ****** In order to prevent accidental writing to a disc, much of the software is concerned with checking that the system is functional, and is of the correct environment. It attempts to ensure that such things as hardware single steppers or software interpreters (such as EXPLORER) are not present, as reading and writing to a disc are time critical functions and must not be interfered with. If any of these fuctions are detected, they will be either locked out so that the software can function correctly, or if they cannot be locked out, the CPU will be locked up after the initial header appears on the screen. Attempts to over-ride these features by modifying the ROM in the module WILL result in unpredictable and usually catastrophic results. Note that the ROM in the module cannot be emulated by such things as Miller's Gram Cracker. SET-UP REQUIRED 1. TI 99/4A Console 2. Disc controller 3. 32k memory expansion 4. Disc Editor module. Insert module, switch on disc controller, memory expansion and console. Press any key as usual, then select the Disc Editor from the Menu. If the software considers the environment correct, then after the header appears on the screen, the Copyright line will appear at the bottom and a request for the Drive number to be input will appear below the header. Enter the drive number (or use enter if it is displayed already), and a request for the Sector number will appear. The input required here is a HEXADECIMAL number (this is because the Sector numbers held on the disc are in HEX) but note that no checking is done to see if the number is a valid sector number for the disc - an out of range number will result in an error code (usually 07) from the DSR in the disk controller. (See also note on errors later). When entering the sector number, full edit facilities are allowed (ie INSERT, DELETE etc), and leading zeros are not required, but to read sector zero, a zero (0) must be entered. The 'BACK' key is enabled at this point, and pressing it will result in a request for the drive number again. KEY FUNCTIONS WHILST IN EDIT MODE FUNCTION 1 Display sector in Hexadecimal FUNCTION 2 Display sector in ASCII FUNCTION 3 Save sector to RAM FUNCTION 4 Display previous sector FUNCTION 5 Select new sector/disc FUNCTION 6 Display next sector FUNCTION 7 Write saved sector FUNCTION 8 Re-write present sector FUNCTION 9 Not used FUNCTION = Quit Having entered the Sector number, press enter and the sector will be displayed in ASCII, with 14 characters per line and the cursor at the top left-hand corner of the sector data. The data can then be edited in ASCII, none ASCII characters may be accepted by the editor (such as Function 0 (>BC)), but only if they are not the recognised Edit function keys. If it is required to Edit the sector in HEX, then press Function 1, and the display will appear in HEX, permitting each nibble to be edited. To revert to ASCII mode, press Funtion 2 - the mode is remembered when changing sectors or drives. As the screen is presented as 14 bytes per line, it is difficult to find out where a particular byte is on the screen, and so a continuously updated cursor address is given on the bottom line of the screen to assist with this. Any data in the sector may be edited, and will NOT be written back to the disc UNLESS specifically requested by pressing Function 8. When Function 8 is pressed, the 'accept' tone is given, and the bottom line will contain the message 'REWRITE THE SECTOR (Y/N)?'. Any input at this point other than 'Y' or 'y' will abort the re-write command, thereby giving protection against accidental writing to the disc. The next sector can be displayed by pressing Function 6, and the previous sector by pressing Funtion 4. Access to a different Drive or Sector can be obtained by pressing Function 5 - the present Drive number is remembered and so 'Enter' is normally only required for this, the sector number is always cleared as it has been found that leaving the previous data there results in confusion. At any time whilst editing a sector, the sector data (as displayed on the screen) can be saved to RAM, and at a later date, the saved data can be written to the disc (to any sector). This feature permits such things as moving single sectors from one disc to another, moving mixed up directories and rescuing discs with a bad sector 0 by copying sector 0 from another disc. The sector data is saved to RAM by pressing Function 3, the indication that the command has been accepted is given by the 'accept' tone. The saved data can be written to the disc at any sector location by displaying (or attempting to display) the appropriate sector and then pressing Function 7. When the key is pressed, the message 'WRITE SAVED SECTOR (Y/N)? will appear on the bottom line, and again, anything but an affirmative answer will result in the command being aborted. ERROR REPORTING. Error reporting is as given in the Editor Assembler Manual for Assembly Language programs, with the exception that an error ending in 'E' or 'F' indicates that the called device service routine was not found (this is usually because the Disc controller is not present or is switched off). NOTE * NOTE * NOTE If an error is reported when trying to access a sector on the disc, then the data displayed on the screen will not be that which appears on the sector requested (though it may be part of it). Usually the data on the screen when a key is pressed for restart will be what was previously in VRAM from the last sector access, although if a sector is partially read, then the data which was read successfully will appear along with some previous data. EXAMPLE OF LOCATING A FILE ON THE DISC. Read sector 2 in ASCII mode, the file name of which this is the directory will appear in the first 10 bytes. If this is not the file you want to find, then press 'Next Sector' until the correct file name is found. On the third line down in the sector data take the first four bytes. Three of these bytes give the sector number at which the file starts. The bytes are arranged as B C X A where the sector number is A B C. For instance if the first four bytes are A421 then the sector number is 1A4. Press Function five, then 'Enter' then the sector number as required and the sector displayed is the first sector of the appropriate file. ********** Whilst every care has been taken in the writing of the software, the author does not guarantee that there is not some bug lurking in it which will destroy data on a disc (though it has been thoroughly tested by various people). Accordingly, when using the Disc Editor, it is up to the user to ensure that no attempt is made to edit a disc which contains non-reproducable data which may be destroyed. If any 'bugs' are found, or you have any suggestions or comments, then please communicate them to: Colin Hinson 119 High Street Blunham Beds.