mt-32-display.cpp
author František Kučera <franta-hg@frantovo.cz>
Tue, 19 May 2020 17:04:22 +0200
branchv_0
changeset 2 a84830179027
parent 1 6733bd832b61
child 3 51a8362261a9
permissions -rw-r--r--
filter ASCII characters
     1 /**
     2  * SysEx message encoder for Roland MT-32
     3  * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
     4  *
     5  * This program is free software: you can redistribute it and/or modify
     6  * it under the terms of the GNU General Public License as published by
     7  * the Free Software Foundation, version 3 of the License.
     8  *
     9  * This program is distributed in the hope that it will be useful,
    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  * GNU General Public License for more details.
    13  *
    14  * You should have received a copy of the GNU General Public License
    15  * along with this program. If not, see <http://www.gnu.org/licenses/>.
    16  */
    17 #include <iostream>
    18 #include <iomanip>
    19 
    20 /**
    21  * Translates text from standard input to a hex-formatted System Exclusive (SysEx) message for Roland MT-32,
    22  * which instructs the unit to show given text on the display.
    23  * 
    24  * Roland MT-32 is capable to display 20 characters.
    25  * Longer messages are silently truncated by the MT-32 unit (this software does not check the length).
    26  * 
    27  * The SysEx message contains a checksum.
    28  * If the checksum is wrong, the MT-32 unit shows the "Exc. Checksum error" message for few seconds
    29  * and then returns back to the default screen.
    30  * 
    31  * Only printable ASCII characters are supported. Other characters (bytes) are replaced by "."
    32  * 
    33  * Some characters are displayed differently:
    34  *   ASCII   MT-32
    35  *       ~   →
    36  *       \   ¥
    37  * 
    38  * Usage examples:
    39  *     amidi --port="hw:2,0,0" --send-hex="$(echo -n '   Run GNU/Linux    ' | ./mt-32-display )"
    40  *     while read message; do amidi --port="hw:2,0,0" --send-hex="$(echo -n "$message" | ./mt-32-display )"; done
    41  * 
    42  * @param argc
    43  * @param argv
    44  * @return 
    45  */
    46 int main(int argc, char**argv) {
    47 	std::cout << "f0 41 10 16 12 20 00 00 ";
    48 	std::cout << std::hex << std::setfill('0');
    49 
    50 	int sum = 0;
    51 
    52 	// 20 00 00 = display message
    53 	sum += 0x20;
    54 	sum += 0x00;
    55 	sum += 0x00;
    56 
    57 	for (char ch; std::cin.read(&ch, 1).good();) {
    58 		if (ch < 32 || ch > 126) ch = '.';
    59 		std::cout << std::setw(2) << ((int) ch) << " ";
    60 		sum += ch;
    61 	}
    62 
    63 	sum %= 128;
    64 	sum = 128 - sum;
    65 	std::cout << std::setw(2) << sum;
    66 	std::cout << " f7";
    67 
    68 	std::cout << std::endl;
    69 	return 0;
    70 }