¢¢ -------------¢ B - T A P E¢ -------------¢¢ Version 1.0¢¢ for BW-DOS and SpartaDOS 3.2¢¢ By Jiri Bernasek (BEWESOFT)¢¢¢¢¢ INTRODUCTION¢¢ In the Czech republic (the country where I live) most Atari XL/XE users have no disk drive. At the begin, the disk drives wasn't available here, and when they later appeared on the market, they was pretty expensive. Because of this, the tape recorder XC12 is the only data-storage device not only for game-freaks, but also for many "serious" users.¢ Unfortunately, the original tape-system (the "C:" device) is not good for daily use. It is slow, and also not safe. Because of this, several tape recorder upgrades were built in the eastern part of Europe during the previous years. All these systems are working with a little hardware modification inside the tape recorder. The most popular one is called "Turbo", and it was built in the Atari user club of Prague. The hardware isn't bad, but the first software was really awful, and - unfortunately - became very popular. It was just a little game-loader, with the file-format copied from poor Sinclair ZX Spectrum. Many programs were then modified (cracked) for this "system" - it was even necessary to add a quite long new tape handler to every "serious" program, because no CIO-handler was available. In fact, the original "Turbo" gave only high speed, without of compatibility.¢ Later, the software was improved. After a few experiments with linking the new tape-system under CIO, finally TT-DOS appeared. It is a DOS 2.5 clone with a high-speed tape handler "B:" included. In my opinion, this is the first version of "Turbo", that goes behind the original "C:" handler, and gives something more. Not only high speed, but also a DOS-alike operation. And comfort - for example when the reading fails, no problem: Simply rewind the tape, and read the bad block again (no need to repeat reading of the whole file).¢ A few months ago, they asked me to link this tape-system to my BW-DOS. So, now I'm releasing "B-TAPE". It is an even more improved version of this popular tape-system, compatible with BW-DOS and also SpartaDOS 3.2. It was made especially for czech users, but I decided to release also an English version. I don't think that a system like this can become popular in countries, where almost everyone have a disk drive, but may be that someone will be interested...¢ Well, you may wonder why I'm writting all this. It is for you, "western" users, to understand why the "B-TAPE" was made, where it came from, and what is it good for. Now, a real "introduction" to the program follows...¢¢ B-TAPE is an advanced high-speed tape system for use with BW-DOS or SpartaDOS 3.2d, 3.2e, or 3.2f. The data-transmission is 5-10 times faster than the standard "C:" handler (depending on selected mode), and is safe (sometimes even more than "C:"). The file-format is compatible with TT-DOS (an older czech DOS for both disk and tape).¢ B-TAPE works only with a tape-recorder modified for "Turbo". It's a pretty simple modification, and it doesn't affect the original function. Look at chapter "Hardware" for more info.¢ The B-TAPE package contains also a kind of Micro-DOS compatible loader for starting games etc. It can load almost every file-based games, demos etc. - also these ones with intros, depacking routines, and other things between loading.¢ With B-TAPE, it's also possible to use BW-DOS with no disk drive. But it's clear that such a configuration is quite hard to use. For using BW-DOS with no disk drive, Ramdisk is strongly recommended.¢¢¢ HARDWARE¢¢ B-TAPE needs a simple hardware-modification inside the tape recorder. This modification is called "Turbo", and is available from: JRC, Chaloupeckeho 1913, 169 00 Praha 6, Czech republic, tel./fax +42 2 354979, fax +42 2 521258. They also sell modified new recorders.¢ For the Atari users who live too far, the documentation of the upgrade is included. I simply examined my (modified) recorder, and wrote the following info. Proceed at your own risk!¢ The basic idea is to add a second operation-mode to the recorder. It is only for reading, the recording section is almost unchanged. The new mode is selected by the COMMAND line "Low" at the same time with MOTOR line "High" (tape recorder on). (This occurs only while reading from tape, so the COMMAND line "Low" may not cause any troubles with other SIO devices - the DATA OUT line is off.) The signal from tape then goes (after amplification of course) directly do the DATA IN line (not via the decoding circuit).¢ The tape recorder Atari XC12 with upgrade is shown on picture "XCTURBO.PIC" - use any painter software for hi-res graphics (Basic mode 8+16) to view. The modification is following:¢ Remove C4, C6, C13, D3, D4, and R23. Add a 68kohm resistor between U1c inputs as shown on picture. Replace R24, R38, and R6 to match the values shown on picture. Add a transistor (for example BC546, almost any universal NPN type is OK) with a 47kohm resistor and two diodes - as shown. You can use the diodes that you just removed from the positions D3 and D4.¢ Open the I/O connector at the end of cable. Remove the wire from pin 11 (orange or red), and place it to pin 7. Add a 10nF capacitor between these pins (7 and 11).¢ After the modification, the recorder must work in the same way as before. And of course, B-TAPE should work also. If it doesn't work, and you didn't find any mistake, try to check the values of components inside the recorder (and replace to match the values shown on picture). If you experience noises on the data-line, try to place a small capacitor (22pF or so...) at the position C6 (the original capacitor is removed to increase frequency-range, and so allow high-speed transmission).¢ This simple upgrade decreases the volume of audio signal that goes from tape to TV-speaker. If you don't like this, leave the line from pin 11 of I/O connector to C12 unchanged (add no capacitor into connector, and don't link it to the added transistor), and connect the emitter of new (added) transistor directly to pin 7 of I/O connector using a special wire. Unfortunately, this wire must be placed at the outside of the original I/O cable.¢¢¢ INSTALLATION¢¢ The high-speed tape system is supported by a new resident command "BTAPE". This software doesn't affect the original "C:" handler.¢¢BTAPE [mode][speed][/memory]¢ (Resident command)¢ mode ..... SS, SD, LS, LD¢ speed .... 0-20¢ memory ... B[bank][,address]¢ O[address] or OX¢¢ This command installs a new tape handler "B:" that allows the high speed operation. All parameters excepting "memory" may be changed by starting this command again; in this case it isn't necessary to repeat the unchanged parameters. The function of the parameters is following:¢¢ "mode" may be "SS", "SD", "LS", or "LD". The first letter controls the length of gaps between blocks - "S" is for short gaps, and "L" means long gaps. The second letter controls the function of double blocks - "S" means single blocks, "D" is for double blocks. Default is "SS".¢ The parameter "speed" allows you to select one of the 21 possible transmission speeds. Default is 12. Both the parameters "mode" and "speed" are important only while recording data to tape. While reading from tape, the B-TAPE software recognizes the used mode and speed automatically. More info about these parameters will come later.¢¢ The last parameter "memory" allows you to select, where will be the main part of BTAPE program in memory. This resident is quite long (3kB), so installing it into low memory may cause troubles with too high MEMLO value. Because of this, the resident code of BTAPE may be also installed under OS-ROM, or into a Ramdisk bank. This reduces the size of resident code in low memory to minimum (110 bytes).¢ Default setting (with no "memory" parameter) is to install the whole program into low memory. This increases the MEMLO value a lot, so many programs may not work in this mode. The DOS commands and Atari Basic are OK.¢ The parameter "/O" causes the resident code of BTAPE to be installed under OS-ROM. In this mode, the compatibility is like with SpartaDOS. MEMLO is OK, but programs like Turbo Basic or XLRDISK may not work. Advanced users may add a hexadecimal address after "/O" (BTAPE will be then installed at the specified address (the length of the code is $BFC - for version 1.0), and so it may work with programs that are using just a part of memory under OS-ROM). Under SpartaDOS 3.2, you must use parameter "/OX" while installing BTAPE under OS-ROM. The "AINIT" function then doesn't work, and the errors in CP are shown only as numbers (both the functions are removed to provide space for BTAPE). The parameter "/OX" may be used only under Sparta.¢ With the parameter "/B", the BTAPE resident code will be placed into a Ramdisk bank. (Advanced users may add a bank number (value for $D301) and address when necessary.) This is the most universal mode (but you must have min. 128kB RAM). The "RAMDISK" command must be then installed with a configuration file, to reserve a bank for BTAPE (see later). The default bank used by BTAPE is $E3. You can also use the "E" parameter, but in this case the capacity of Ramdisk will be reduced much more (64kB instead of 16).¢¢¢ RAMDISK configuration¢¢ To reserve a bank of Ramdisk memory for another use (in this case BTAPE), you must use a configuration file every time when you call the "RAMDISK" command. In the B-TAPE package, there are four configuration files included. These files are reserving the bank $E3 (that is used by BTAPE), and they are designed for the following memory-expansions: "B_130XE.RD" is for Atari 130XE (64kB), "B_COMPY.RD" is for a "Compy Shop" type expansion (256kB), "B_RAMBO.RD" is for a "Rambo" type (256kB), and "B_NEWELL.RD" should work with a "Newell" 1MB expansion.¢¢ Advanced users may create another Ramdisk-configuration files using for example the command "HEXEDIT". The file contains a list of banks available for RAMDISK use, each byte for one bank (values for $D301).¢¢¢
