1
0
mirror of https://github.com/pkimpel/retro-b5500.git synced 2026-02-13 19:54:50 +00:00
Files
pkimpel.retro-b5500/webUI/B5500MagTapeDrive.js
paul.kimpel@digm.com 085bfd48da Release emulator version 0.19:
1. Implement write to tape and persistence of tape image data.
2014-01-10 22:17:12 +00:00

1420 lines
60 KiB
JavaScript

/***********************************************************************
* retro-b5500/emulator B5500MagTapeDrive.js
************************************************************************
* Copyright (c) 2013, Nigel Williams and Paul Kimpel.
* Licensed under the MIT License, see
* http://www.opensource.org/licenses/mit-license.php
************************************************************************
* B5500 Magnetic Tape Drive Peripheral Unit module.
*
* Defines a magnetic tape drive peripheral unit type, emulating the
* Burroughs B425 tape transport at 800 bits/inch.
*
* Internally, tape images are maintained in ".bcd" format. Each character
* frame on the tape is represented by one 8-bit byte in memory. The low-
* order six bits of each frame are the character bits (in BCL if even
* parity or BIC if odd parity). The seventh bit is even or odd parity,
* and the high-order bit in the byte is one if this frame starts a block.
* EOF is represented as a one-frame block with a code of 0x8F in both
* odd- and even-parity recording.
*
************************************************************************
* 2013-10-26 P.Kimpel
* Original version, from B5500CardReader.js.
* 2013-01-01 P.Kimpel
* Add write capabilty, read capability for ASCII tape images, and
* selectable tape lengths.
***********************************************************************/
"use strict";
/**************************************/
function B5500MagTapeDrive(mnemonic, unitIndex, designate, statusChange, signal) {
/* Constructor for the MagTapeDrive object */
var that = this;
var x = ((mnemonic.charCodeAt(2) - "A".charCodeAt(0) + 1)*30);
this.mnemonic = mnemonic; // Unit mnemonic
this.unitIndex = unitIndex; // Ready-mask bit number
this.designate = designate; // IOD unit designate number
this.statusChange = statusChange; // external function to call for ready-status change
this.signal = signal; // external function to call for special signals (not used here)
this.timer = null; // setCallback() token
this.initiateStamp = 0; // timestamp of last initiation (set by IOUnit)
this.clear();
this.window = window.open("", mnemonic);
if (this.window) {
this.shutDown(); // destroy the previously-existing window
this.window = null;
}
this.doc = null;
this.window = window.open("../webUI/B5500MagTapeDrive.html", mnemonic,
"scrollbars=no,resizable,width=560,height=120,left="+x+",top="+x);
this.window.addEventListener("load", function windowLoad() {
that.tapeDriveOnLoad();
}, false);
this.progressBar = null;
this.reelIcon = null;
}
// this.tapeState enumerations
B5500MagTapeDrive.prototype.tapeUnloaded = 0;
B5500MagTapeDrive.prototype.tapeLocal = 1;
B5500MagTapeDrive.prototype.tapeRemote = 2;
B5500MagTapeDrive.prototype.density = 800;
// 800 bits/inch
B5500MagTapeDrive.prototype.charsPerSec = 72000;
// B425, 90 inches/sec @ 800 bits/inch
B5500MagTapeDrive.prototype.gapLength = 0.75;
// inter-block blank tape gap [inches]
B5500MagTapeDrive.prototype.startStopTime = 0.0045 + 0.0042;
// tape start+stop time [sec]
B5500MagTapeDrive.prototype.rewindSpeed = 320;
// rewind speed [inches/sec]
B5500MagTapeDrive.prototype.maxTapeLength = 2410*12;
// max tape length on reel [inches]
B5500MagTapeDrive.prototype.postEOTLength = 20*12;
// length of tape after EOT reflector [inches]
B5500MagTapeDrive.prototype.maxBlankFrames = 9*12*B5500MagTapeDrive.prototype.density;
// max blank tape length, 9 feet [frames]
B5500MagTapeDrive.prototype.bcdTapeMark = 0x8F;
// .bcd image EOF code
B5500MagTapeDrive.prototype.reelCircumference = 10*3.14159;
// max circumference of tape [inches]
B5500MagTapeDrive.prototype.maxSpinAngle = 37;
// max angle to rotate reel image [degrees]
B5500MagTapeDrive.prototype.bcdXlateInOdd = [ // Translate odd parity BIC to ASCII
0xFF,0x31,0x32,0xFF,0x34,0xFF,0xFF,0x37,0x38,0xFF,0xFF,0x40,0xFF,0x3A,0x3E,0xFF, // 00-0F
0x2B,0xFF,0xFF,0x43,0xFF,0x45,0x46,0xFF,0xFF,0x49,0x2E,0xFF,0x26,0xFF,0xFF,0x7E, // 10-1F
0x7C,0xFF,0xFF,0x4C,0xFF,0x4E,0x4F,0xFF,0xFF,0x52,0x24,0xFF,0x2D,0xFF,0xFF,0x7B, // 20-2F
0xFF,0x2F,0x53,0xFF,0x55,0xFF,0xFF,0x58,0x59,0xFF,0xFF,0x25,0xFF,0x3D,0x5D,0xFF, // 30-3F
0x30,0xFF,0xFF,0x33,0xFF,0x35,0x36,0xFF,0xFF,0x39,0x23,0xFF,0x3F,0xFF,0xFF,0x7D, // 40-4F
0xFF,0x41,0x42,0xFF,0x44,0xFF,0xFF,0x47,0x48,0xFF,0xFF,0x5B,0xFF,0x28,0x3C,0xFF, // 50-5F
0xFF,0x4A,0x4B,0xFF,0x4D,0xFF,0xFF,0x50,0x51,0xFF,0xFF,0x2A,0xFF,0x29,0x3B,0xFF, // 60-6F
0x20,0xFF,0xFF,0x54,0xFF,0x56,0x57,0xFF,0xFF,0x5A,0x2C,0xFF,0x21,0xFF,0xFF,0x22]; // 70-7F
B5500MagTapeDrive.prototype.bcdXlateOutOdd = [ // Translate ASCII to odd Parity BIC
0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C, // 00-0F
0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C,0x4C, // 10-1F
0x70,0x7C,0x7F,0x4A,0x2A,0x3B,0x1C,0x4C,0x5D,0x6D,0x6B,0x10,0x7A,0x2C,0x1A,0x31, // 20-2F
0x40,0x01,0x02,0x43,0x04,0x45,0x46,0x07,0x08,0x49,0x0D,0x6E,0x5E,0x3D,0x0E,0x4C, // 30-3F
0x0B,0x51,0x52,0x13,0x54,0x15,0x16,0x57,0x58,0x19,0x61,0x62,0x23,0x64,0x25,0x26, // 40-4F
0x67,0x68,0x29,0x32,0x73,0x34,0x75,0x76,0x37,0x38,0x79,0x5B,0x4C,0x3E,0x4C,0x4C, // 50-5F
0x4C,0x51,0x52,0x13,0x54,0x15,0x16,0x57,0x58,0x19,0x61,0x62,0x23,0x64,0x25,0x26, // 60-6F
0x67,0x68,0x29,0x32,0x73,0x34,0x75,0x76,0x37,0x38,0x79,0x2F,0x20,0x4F,0x1F,0x4C]; // 70-7F
B5500MagTapeDrive.prototype.bcdXlateInEven = [ // Translate even parity BCL to ASCII
0x3F,0xFF,0xFF,0x33,0xFF,0x35,0x36,0xFF,0xFF,0x39,0x30,0xFF,0x40,0xFF,0xFF,0x7D, // 00-0F
0xFF,0x2F,0x53,0xFF,0x55,0xFF,0xFF,0x58,0x59,0xFF,0xFF,0x2C,0xFF,0x3D,0x5D,0xFF, // 10-1F
0xFF,0x4A,0x4B,0xFF,0x4D,0xFF,0xFF,0x50,0x51,0xFF,0xFF,0x24,0xFF,0x29,0x3B,0xFF, // 20-2F
0x26,0xFF,0xFF,0x43,0xFF,0x45,0x46,0xFF,0xFF,0x49,0x2B,0xFF,0x5B,0xFF,0xFF,0x7E, // 30-3F
0xFF,0x31,0x32,0xFF,0x34,0xFF,0xFF,0x37,0x38,0xFF,0xFF,0x23,0xFF,0x3A,0x3E,0xFF, // 40-4F
0x20,0xFF,0xFF,0x54,0xFF,0x56,0x57,0xFF,0xFF,0x5A,0x21,0xFF,0x25,0xFF,0xFF,0x22, // 50-5F
0x2D,0xFF,0xFF,0x4C,0xFF,0x4E,0x4F,0xFF,0xFF,0x52,0x7C,0xFF,0x2A,0xFF,0xFF,0x7B, // 60-6F
0xFF,0x41,0x42,0xFF,0x44,0xFF,0xFF,0x47,0x48,0xFF,0xFF,0x2E,0xFF,0x28,0x3C,0xFF]; // 70-7F
B5500MagTapeDrive.prototype.bcdXlateOutEven = [ // Translate ASCII to even parity BCL
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // 00-0F
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // 10-1F
0x50,0x5A,0x5F,0x4B,0x2B,0x5C,0x30,0x00,0x7D,0x2D,0x6C,0x3A,0x1B,0x60,0x7B,0x11, // 20-2F
0x0A,0x41,0x42,0x03,0x44,0x05,0x06,0x47,0x48,0x09,0x4D,0x2E,0x7E,0x1D,0x4E,0x00, // 30-3F
0x0C,0x71,0x72,0x33,0x74,0x35,0x36,0x77,0x78,0x39,0x21,0x22,0x63,0x24,0x65,0x66, // 40-4F
0x27,0x28,0x69,0x12,0x53,0x14,0x55,0x56,0x17,0x18,0x59,0x3C,0x00,0x1E,0x00,0x00, // 50-5F
0x00,0x71,0x72,0x33,0x74,0x35,0x36,0x77,0x78,0x39,0x21,0x22,0x63,0x24,0x65,0x66, // 60-6F
0x27,0x28,0x69,0x12,0x53,0x14,0x55,0x56,0x17,0x18,0x59,0x6F,0x6A,0x0F,0x3F,0x00]; // 70-7F
/**************************************/
B5500MagTapeDrive.prototype.$$ = function $$(e) {
return this.doc.getElementById(e);
};
/**************************************/
B5500MagTapeDrive.prototype.clear = function clear() {
/* Initializes (and if necessary, creates) the reader unit state */
this.ready = false; // ready status
this.busy = false; // busy status
this.errorMask = 0; // error mask for finish()
this.finish = null; // external function to call for I/O completion
this.image = null; // tape drive "reel of tape"
this.imgEOTInches = 0; // tape image length to EOT marker [inches]
this.imgIndex = 0; // 0-relative offset to next tape block to be read
this.imgLength = 0; // current input buffer length (characters)
this.imgMaxInches = 0; // tape image max length [inches]
this.imgTopIndex = 0; // highest-used offset within image data
this.imgWritten = false; // tape image has been modified (implies writable)
this.tapeState = this.tapeUnloaded; // tape drive state
this.angle = 0; // current rotation angle of reel image [degrees]
this.tapeInches = 0; // number of inches currently up-tape
this.writeRing = false; // true if write ring is present and tape is writable
this.atBOT = true; // true if tape at BOT
this.atEOT = false; // true if tape at EOT
this.buffer = null; // IOUnit buffer
this.bufLength = 0; // IOUnit buffer length
this.bufIndex = 0; // IOUnit buffer current offset
};
/**************************************/
B5500MagTapeDrive.prototype.hasClass = function hasClass(e, name) {
/* returns true if element "e" has class "name" in its class list */
var classes = e.className;
if (!e) {
return false;
} else if (classes == name) {
return true;
} else {
return (classes.search("\\b" + name + "\\b") >= 0);
}
};
/**************************************/
B5500MagTapeDrive.prototype.addClass = function addClass(e, name) {
/* Adds a class "name" to the element "e"s class list */
if (!this.hasClass(e, name)) {
e.className += (" " + name);
}
};
/**************************************/
B5500MagTapeDrive.prototype.removeClass = function removeClass(e, name) {
/* Removes the class "name" from the element "e"s class list */
e.className = e.className.replace(new RegExp("\\b" + name + "\\b\\s*", "g"), "");
};
/**************************************/
B5500MagTapeDrive.prototype.spinReel = function spinReel(inches) {
/* Rotates the reel image icon an appropriate amount based on the number of
inches of tape movement. The rotation is limited to 33 degrees in either
direction so that movement remains apparent to the viewer */
var circumference = this.reelCircumference*(1 - this.tapeInches/this.maxTapeLength/2);
var angle = inches/circumference*360;
if (angle >= this.maxSpinAngle) {
angle = this.maxSpinAngle;
} else if (angle < -this.maxSpinAngle) {
angle = -this.maxSpinAngle;
}
this.angle = (this.angle + angle)%360;
this.reelIcon.style.transform = "rotate(" + this.angle.toFixed(0) + "deg)";
};
/**************************************/
B5500MagTapeDrive.prototype.setAtBOT = function setAtBOT(atBOT) {
/* Controls the ready-state of the tape drive */
if (atBOT ^ this.atBOT) {
this.atBOT = atBOT;
if (atBOT) {
this.imgIndex = 0;
this.tapeInches = 0;
this.addClass(this.$$("MTAtBOTLight"), "whiteLit");
this.progressBar.value = this.imgMaxInches;
this.reelIcon.style.transform = "rotate(0deg)";
} else {
this.removeClass(this.$$("MTAtBOTLight"), "whiteLit");
}
}
};
/**************************************/
B5500MagTapeDrive.prototype.setAtEOT = function setAtEOT(atEOT) {
/* Controls the ready-state of the tape drive */
if (atEOT ^ this.atEOT) {
this.atEOT = atEOT;
if (atEOT) {
this.addClass(this.$$("MTAtEOTLight"), "whiteLit");
this.progressBar.value = 0;
} else {
this.removeClass(this.$$("MTAtEOTLight"), "whiteLit");
}
}
};
/**************************************/
B5500MagTapeDrive.prototype.setTapeUnloaded = function setTapeUnloaded() {
/* Controls the loaded/unloaded-state of the tape drive */
if (this.tapeState == this.tapeLocal && this.atBOT) {
this.tapeState = this.tapeUnloaded;
this.image = null; // release the tape image to GC
this.imgIndex = this.imgLength = 0;
this.writeRing = false;
this.ready = false;
this.statusChange(0);
this.$$("MTUnloadBtn").disabled = true;
this.$$("MTLoadBtn").disabled = false;
this.$$("MTLocalBtn").disabled = true;
this.$$("MTRemoteBtn").disabled = true;
this.$$("MTRewindBtn").disabled = true;
this.$$("MTWriteRingBtn").disabled = true;
this.$$("MTFileName").value = "";
this.removeClass(this.$$("MTRemoteBtn"), "yellowLit");
this.addClass(this.$$("MTLocalBtn"), "yellowLit");
this.removeClass(this.$$("MTWriteRingBtn"), "redLit");
this.addClass(this.$$("MTUnloadedLight"), "whiteLit");
this.setAtBOT(false);
this.setAtEOT(false);
this.progressBar.value = 0;
this.reelIcon.style.visibility = "hidden";
if (this.timer) {
clearCallback(this.timer);
this.timer = null;
}
}
};
/**************************************/
B5500MagTapeDrive.prototype.setTapeRemote = function setTapeRemote(ready) {
/* Controls the ready-state of the tape drive */
if (this.tapeState != this.tapeUnloaded) {
this.$$("MTLoadBtn").disabled = true;
this.$$("MTUnloadBtn").disabled = ready;
this.$$("MTLocalBtn").disabled = !ready;
this.$$("MTRemoteBtn").disabled = ready;
this.$$("MTWriteRingBtn").disabled = false;
this.$$("MTRewindBtn").disabled = ready;
this.ready = ready;
if (ready) {
this.tapeState = this.tapeRemote;
this.statusChange(1);
this.removeClass(this.$$("MTLocalBtn"), "yellowLit");
this.addClass(this.$$("MTRemoteBtn"), "yellowLit");
} else {
this.tapeState = this.tapeLocal;
this.statusChange(0);
this.removeClass(this.$$("MTRemoteBtn"), "yellowLit");
this.addClass(this.$$("MTLocalBtn"), "yellowLit");
}
}
};
/**************************************/
B5500MagTapeDrive.prototype.setWriteRing = function setWriteRing(writeRing) {
/* Controls the write-ring (write-enabled state of the tape drive. In Local state,
writable status can be set or reset; in Remote state, it can only be reset */
switch (this.tapeState) {
case this.tapeLocal:
case this.tapeRemote:
if (this.writeRing && !writeRing) {
this.writeRing = false;
this.removeClass(this.$$("MTWriteRingBtn"), "redLit");
}
break;
}
};
/**************************************/
B5500MagTapeDrive.prototype.loadTape = function loadTape() {
/* Loads a tape into memory based on selections in the MTLoad window */
var $$$ = null; // getElementById shortcut for loader window
var doc = null; // loader window.document
var eotInches = 0; // tape inches until EOT marker
var file = null; // FileReader instance
var fileSelect = null; // file picker element
var formatSelect = null; // tape format list element
var maxInches = 0; // maximum tape inches in tape image
var mt = this; // this B5500MagTapeDrive instance
var tapeFormat = ""; // tape format code (bcd, aod, aev, etc.)
var tapeInches = 0; // selected tape length in inches
var tapeLengthSelect = null; // tape length list element
var win = this.window.open("B5500MagTapeLoadPanel.html", this.mnemonic + "Load",
"scrollbars=no,resizable,width=508,height=112");
var writeRing = false; // true if write-enabled
var writeRingCheck = null; // tape write ring checkbox element
function fileSelector_onChange(ev) {
/* Handle the <input type=file> onchange event when a file is selected */
var fileExt;
var fileName;
var x;
file = ev.target.files[0];
fileName = file.name;
x = fileName.lastIndexOf(".");
fileExt = (x > 0 ? fileName.substring(x) : "");
writeRingCheck.checked = false;
tapeLengthSelect.disabled = true;
switch (fileExt) {
case ".bcd":
tapeFormat = "bcd";
break;
case ".tap":
tapeFormat = "tap";
break;
default:
tapeFormat = "aod";
break;
} // switch fileExt
for (x=formatSelect.length-1; x>=0; x--) {
if (formatSelect.options[x].value == tapeFormat) {
formatSelect.selectedIndex = x;
break;
}
} // for x
}
function finishLoad() {
/* Finishes the tape loading process and closes the loader window */
mt.imgIndex = 0;
mt.imgLength = mt.image.length;
mt.tapeInches = 0;
mt.imgEOTInches = eotInches;
mt.imgMaxInches = tapeInches;
mt.progressBar.max = mt.imgMaxInches;
mt.progressBar.value = mt.imgMaxInches;
mt.removeClass(mt.$$("MTUnloadedLight"), "whiteLit");
mt.setAtEOT(false);
mt.setAtBOT(true);
mt.tapeState = mt.tapeLocal; // setTapeRemote() requires it not be unloaded
mt.setTapeRemote(false);
mt.reelIcon.style.visibility = "visible";
mt.imgWritten = false;
mt.writeRing = writeRing;
if (writeRing) {
mt.addClass(mt.$$("MTWriteRingBtn"), "redLit");
} else {
mt.removeClass(mt.$$("MTWriteRingBtn"), "redLit");
}
win.close();
}
function bcdLoader_onLoad(ev) {
/* Loads a ".bcd" tape image into the drive */
var blockLength;
var image = new Uint8Array(ev.target.result);
var imageSize;
var x;
mt.imgTopIndex = image.length;
if (writeRing) {
eotInches = tapeInches;
tapeInches += mt.postEOTLength;
imageSize = tapeInches*mt.density;
if (image.length > imageSize) {
eotInches = image.length/mt.density;
imageSize = image.length + mt.postEOTLength*mt.density;
tapeInches = imageSize/mt.density;
}
mt.image = new Uint8Array(new ArrayBuffer(imageSize));
for (x=image.length-1; x>=0; x--) {
mt.image[x] = image[x];
}
} else {
mt.image = image;
imageSize = image.length;
tapeInches = 0;
x = 0;
while (x < imageSize) {
x++;
blockLength = 1;
while (x < imageSize && image[x] < 0x80) {
x++;
blockLength++;
} // while for blockLength
tapeInches += blockLength/mt.density + mt.gapLength;
} // while for imageSize
eotInches = tapeInches + mt.postEOTLength;
}
finishLoad();
}
function blankLoader() {
/* Loads a blank tape image into the drive */
writeRing = true;
eotInches = tapeInches;
tapeInches += mt.postEOTLength;
mt.image = new Uint8Array(new ArrayBuffer(tapeInches*mt.density));
mt.image[0] = 0x81; // put a little noise on the tape to avoid blank-tape timeouts
mt.image[1] = 0x03;
mt.image[2] = 0x8F;
mt.imgTopIndex = 3;
finishLoad();
}
function tapLoader_onLoad(ev) {
/* Loads a ".tap" tape image into the drive */
/* To be Provided */
}
function textLoader_onLoad(ev) {
/* Loads a text image as either odd or even parity bcd data */
var block; // ANSI text of current block
var blockLength; // length of current ASCII block
var eolRex = /([^\n\r\f]*)((:?\r[\n\f]?)|\n|\f)?/g;
var image = ev.target.result; // ANSI tape image
var imageLength = image.length; // length of ANSI tape image
var imageSize; // size of final tape image [bytes]
var inches = 0; // tape inches occupied by image data
var index = 0; // image index of next ANSI block
var match; // result of eolRex.exec()
var offset = 0; // index into mt.image
var table = (tapeFormat == "aev" ? mt.bcdXlateOutEven : mt.bcdXlateOutOdd);
var x; // for loop index
if (!writeRing) {
imageSize = imageLength;
} else {
eotInches = tapeInches;
tapeInches += mt.postEOTLength;
imageSize = tapeInches*mt.density;
if (imageLength > imageSize) {
eotInches = imageLength/mt.density;
imageSize = imageLength + mt.postEOTLength*mt.density;
tapeInches = imageSize/mt.density;
}
}
mt.image = new Uint8Array(new ArrayBuffer(imageSize));
do {
eolRex.lastIndex = index;
match = eolRex.exec(image);
if (!match) {
break;
} else {
index += match[0].length;
block = match[1];
blockLength = block.length;
inches += blockLength/mt.density + mt.gapLength;
if (block == "}") {
mt.image[offset++] = mt.bcdTapeMark;
} else if (blockLength > 0) {
mt.image[offset++] = table[block.charCodeAt(0) & 0x7F] | 0x80;
for (x=1; x<blockLength; x++) {
mt.image[offset++] = table[block.charCodeAt(x) & 0x7F];
}
}
}
} while (index < imageLength);
mt.imgTopIndex = offset;
if (!writeRing) {
tapeInches = inches;
eotInches = tapeInches + mt.postEOTLength;
}
finishLoad();
}
function tapeLoadOK(ev) {
/* Handler for the OK button. Does the actual tape load */
var tape;
tapeFormat = formatSelect.value;
if (!(file || tapeFormat == "blank")) {
win.alert("File must be selected unless loading a blank tape");
} else {
tapeInches = (parseInt(tapeLengthSelect.value) || 2400)*12;
writeRing = writeRingCheck.checked;
mt.$$("MTFileName").value = (file ? file.name : "");
switch (tapeFormat) {
case "aod":
case "aev":
tape = new FileReader();
tape.onload = textLoader_onLoad;
tape.readAsText(file);
break;
case "bcd":
tape = new FileReader();
tape.onload = bcdLoader_onLoad;
tape.readAsArrayBuffer(file);
break;
case "tap":
tape = new FileReader();
tape.onload = tapLoader_onLoad;
tape.readAsArrayBuffer(file);
break;
default:
mt.$$("MTFileName").value = (file ? file.name : "(blank tape)");
blankLoader();
break;
} // switch
}
}
function tapeLoadOnLoad (ev) {
/* Driver for the tape loader window */
doc = win.document;
$$$ = function $$$(id) {
return doc.getElementById(id);
};
fileSelect = $$$("MTLoadFileSelector");
formatSelect = $$$("MTLoadFormatSelect");
writeRingCheck = $$$("MTLoadWriteRingCheck");
tapeLengthSelect = $$$("MTLoadTapeLengthSelect")
doc.title = "B5500 " + mt.mnemonic + " Tape Loader";
fileSelect.addEventListener("change", fileSelector_onChange, false);
formatSelect.addEventListener("change", function loadFormatSelect(ev) {
tapeFormat = ev.target.value;
if (tapeFormat == "blank") {
file = null;
fileSelect.value = null;
writeRingCheck.checked = true;
tapeLengthSelect.disabled = false;
tapeLengthSelect.selectedIndex = tapeLengthSelect.length-1;
}
}, false);
writeRingCheck.addEventListener("click", function loadWriteRingCheck(ev) {
tapeLengthSelect.disabled = !ev.target.checked;
}, false);
$$$("MTLoadOKBtn").addEventListener("click", tapeLoadOK, false);
$$$("MTLoadCancelBtn").addEventListener("click", function loadCancelBtn(ev) {
file = null;
mt.$$("MTFileName").value = "";
win.close();
}, false);
}
mt.$$("MTLoadBtn").disabled = true;
win.moveTo((screen.availWidth-win.outerWidth)/2, (screen.availHeight-win.outerHeight)/2);
win.focus();
win.addEventListener("load", tapeLoadOnLoad, false);
win.addEventListener("unload", function tapeLoadUnload(ev) {
if (win.closed) {
mt.$$("MTLoadBtn").disabled = (mt.tapeState != mt.tapeUnloaded);
}
}, false);
};
/**************************************/
B5500MagTapeDrive.prototype.unloadTape = function unloadTape() {
/* Reformats the tape image data as ASCII text and displays it in a new
window so the user can save or copy/paste it elsewhere */
var doc = null; // loader window.document
var mt = this; // tape drive object
var win = this.window.open("", this.mnemonic + "Unload",
"scrollbars=no,resizable,width=800,height=600");
function unloadDriver() {
/* Converts the tape image to ASCII once the window has displayed the
waiting message */
var buf = new Uint8Array(new ArrayBuffer(8192));
var bufIndex; // offset into ASCII block data
var bufLength = buf.length-2; // max usable block size
var c; // current image byte;
var image = mt.image; // tape image data
var imgLength = mt.imgTopIndex; // tape image active length
var table; // even/odd parity translate table
var text = doc.getElementById("TapeText");
var x = 0; // image data index
while (text.firstChild) {
text.removeChild(text.firstChild);
}
c = image[x];
do {
c &= 0x7F;
table = (mt.bcdXlateInEven[c] < 0xFF ? mt.bcdXlateInEven : mt.bcdXlateInOdd);
bufIndex = 0;
do {
if (bufIndex >= bufLength) {
text.appendChild(doc.createTextNode(String.fromCharCode.apply(null, buf.subarray(0, bufIndex))));
bufIndex = 0;
}
if (c > 0) {
buf[bufIndex++] = table[c];
}
x++;
if (x < imgLength) {
c = image[x];
} else {
break;
}
} while (c < 0x80);
buf[bufIndex++] = 0x0A;
text.appendChild(doc.createTextNode(String.fromCharCode.apply(null, buf.subarray(0, bufIndex))));
} while (x < imgLength);
mt.setTapeUnloaded();
}
win.moveTo((screen.availWidth-win.outerWidth)/2, (screen.availHeight-win.outerHeight)/2);
win.focus();
doc = win.document;
doc.open();
doc.write("<html><head></head><body><pre id=TapeText>Converting... please wait...</pre></body></html>");
doc.close();
doc.title = "B5500 " + this.mnemonic + " Unload Tape";
setCallback(unloadDriver, this, 20); // give the message time to display
};
/**************************************/
B5500MagTapeDrive.prototype.tapeRewind = function tapeRewind(makeReady) {
/* Rewinds the tape. Makes the drive not-ready and delays for an appropriate amount
of time depending on how far up-tape we are. If makeReady is true [valid only when
called from this.rewind()], then readies the unit again when the rewind is complete */
var inches;
var lastStamp = new Date().getTime();
var updateInterval = 30; // ms
function rewindFinish() {
this.timer = null;
this.busy = false;
this.removeClass(this.$$("MTRewindingLight"), "whiteLit");
if (makeReady && this.tapeState == this.tapeRemote) {
this.ready = true;
this.statusChange(1);
}
}
function rewindDelay() {
var stamp = new Date().getTime();
var interval = stamp - lastStamp;
if (interval <= 0) {
interval = updateInterval/2;
}
if (this.tapeInches > 0) {
inches = interval/1000*this.rewindSpeed;
this.tapeInches -= inches;
this.spinReel(-inches);
this.progressBar.value = this.imgMaxInches - this.tapeInches;
lastStamp = stamp;
this.timer = setCallback(rewindDelay, this, updateInterval);
} else {
this.spinReel(6);
this.setAtBOT(true);
this.timer = setCallback(rewindFinish, this, 2000);
}
}
if (this.timer) {
clearCallback(this.timer);
this.timer = null;
}
if (this.tapeState != this.tapeUnloaded && !this.atBOT) {
this.busy = true;
this.ready = false;
this.statusChange(0);
this.setAtEOT(false);
this.addClass(this.$$("MTRewindingLight"), "whiteLit");
this.timer = setCallback(rewindDelay, this, 1000);
}
};
/**************************************/
B5500MagTapeDrive.prototype.MTUnloadBtn_onclick = function MTUnloadBtn_onclick(ev) {
/* Handle the click event for the UNLOAD button */
if (this.imgWritten && this.window.confirm("Do you want to save the tape image data?")) {
this.unloadTape(); // will do setTapeUnloaded() afterwards
} else {
this.setTapeUnloaded();
}
};
/**************************************/
B5500MagTapeDrive.prototype.MTLoadBtn_onclick = function MTLoadBtn_onclick(ev) {
/* Handle the click event for the LOAD button */
this.loadTape();
};
/**************************************/
B5500MagTapeDrive.prototype.MTRemoteBtn_onclick = function MTRemoteBtn_onclick(ev) {
/* Handle the click event for the REMOTE button */
this.setTapeRemote(true);
};
/**************************************/
B5500MagTapeDrive.prototype.MTLocalBtn_onclick = function MTLocalBtn_onclick(ev) {
/* Handle the click event for the LOCAL button */
this.setTapeRemote(false);
};
/**************************************/
B5500MagTapeDrive.prototype.MTWriteRingBtn_onclick = function MTWriteRingBtn_onclick(ev) {
/* Handle the click event for the WRITE RING button */
this.setWriteRing(!this.writeRing);
};
/**************************************/
B5500MagTapeDrive.prototype.MTRewindBtn_onclick = function MTRewindBtn(ev) {
/* Handle the click event for the REWIND button */
this.tapeRewind(false);
};
/**************************************/
B5500MagTapeDrive.prototype.buildErrorMask = function buildErrorMask(chars) {
/* Constructs the final error mask from this.errorMask, the number of residual
characters in the last word, and the current drive state */
var mask = this.errorMask & 0x01FC7FFF; // clear out the char count bits
mask |= (chars & 0x07) << 15;
if (this.atBOT) {
mask |= 0x80000; // tape at BOT
} else if (this.atEOT) {
mask |= 0x40020; // tape at EOT
}
this.errorMask = mask;
return mask;
};
/**************************************/
B5500MagTapeDrive.prototype.bcdSpaceForward = function bcdSpaceForward(checkEOF) {
/* Spaces over the next block (or the remainder of the current block) from the
.bcd tape (this.image) in a forward direction. No data transfer to the IOUnit buffer
takes place, and no parity detection is made. A block is terminated when the next
frame has its high-order bit set, or the end of the tape image data is reached.
checkEOF true=> check for an EOF frame (i.e., we're not spacing the rest of a block)
Exits with the image index pointing to the first frame of the next block (or beyond
the end of the image blob if at EOT) */
var blankCount = 0; // blank tape frame counter
var c; // current character (tape image frame)
var image = this.image; // tape image
var imgLength = this.imgLength; // tape image length
var imgIndex = this.imgIndex; // current tape image offset
if (imgIndex >= imgLength) {
this.errorMask |= 0x10; // report parity error if beyond end of tape
} else {
if (this.atBOT) {
this.setAtBOT(false);
}
c = image[imgIndex];
if (checkEOF && c == this.bcdTapeMark && (imgIndex+1 >= imgLength || image[imgIndex+1] >= 0x80)) {
this.errorMask |= 0x20; // EOF
imgIndex++;
} else {
do {
if (c == 0x00) {
if (++blankCount > this.maxBlankFrames) {
this.errorMask |= 0x100000; // blank tape timeout
break; // kill the read loop
}
} else {
blankCount = 0;
}
if (++imgIndex < imgLength) {
c = image[imgIndex]; // get next char frame
} else {
break; // at end of tape, kill the read loop
}
} while (c < 0x80);
}
}
this.imgIndex = imgIndex;
};
/**************************************/
B5500MagTapeDrive.prototype.bcdSpaceBackward = function bcdSpaceBackward(checkEOF) {
/* Spaces over the next block (or the remainder of the current block) from the
.bcd tape (this.image) in a backward direction. No data transfer to the IOUnit buffer
takes place, and no parity detection is made. A block is terminated when the next
frame has its high-order bit set, or the beginning of the tape image data is reached.
checkEOF true=> check for an EOF frame (i.e., we're not spacing the rest of a block)
Exits with the image index pointing to the first frame of THIS block (or at 0 if
at BOT). This arrangement allows changes between forward/reverse motion to work */
var blankCount = 0; // blank tape frame counter
var c; // current character (tape image frame)
var image = this.image; // tape image
var imgLength = this.imgLength; // tape image length
var imgIndex = this.imgIndex; // current tape image offset
if (imgIndex <= 0) {
this.setAtBOT(true);
this.errorMask |= 0x100000; // set blank-tape bit
} else {
if (this.atEOT) {
this.setAtEOT(false);
}
c = image[--imgIndex];
if (checkEOF && c == this.bcdTapeMark) {
this.errorMask |= 0x20; // EOF
} else {
do {
if (c == 0x00) {
if (++blankCount > this.maxBlankFrames) {
this.errorMask |= 0x100000; // blank tape timeout
break; // kill the read loop
}
} else {
blankCount = 0;
}
if (--imgIndex >= 0) {
c = image[imgIndex]; // get next char frame
} else {
break; // at start of tape, kill the read loop
}
} while (c < 0x80);
}
}
this.imgIndex = imgIndex;
};
/**************************************/
B5500MagTapeDrive.prototype.bcdReadForward = function bcdReadForward(oddParity) {
/* Reads the next block from the .bcd tape (this.image) in a forward direction,
translating the character frames to ANSI character codes based on the translation
table "xlate". The translated data is stored in this.buffer. A block is terminated
when the next frame has its high-order bit set, or the end of the tape image data
is reached. The resulting buffer is always at least one character in length, unless
the block is a tapeMark or the end of the data has been reached.
oddParity 0=Alpha (even parity), 1=Binary (odd parity) read
Exits with the image index pointing to the first frame of the next block (or beyond
the end of the image blob if at EOT). Returns the number of characters read into the
IOUnit buffer */
var blankCount = 0; // blank tape frame counter
var buffer = this.buffer; // IOUnit buffer
var bufLength = this.bufLength // IOUnit buffer length
var bufIndex = 0; // current IOUnit buffer offset
var c; // current character (tape image frame)
var cx; // current character translated to ASCII
var image = this.image; // tape image
var imgLength = this.imgLength; // tape image length
var imgIndex = this.imgIndex; // current tape image offset
var xlate = (oddParity ? this.bcdXlateInOdd : this.bcdXlateInEven);
if (imgIndex >= imgLength) {
this.errorMask |= 0x10; // report parity error if beyond end of tape
} else {
if (this.atBOT) {
this.setAtBOT(false);
}
c = image[imgIndex];
if (c == this.bcdTapeMark && (imgIndex+1 >= imgLength || image[imgIndex+1] >= 0x80)) {
this.errorMask |= 0x20; // EOF
imgIndex++;
} else {
c &= 0x7F; // zap the start-of-block bit
do {
if (c == 0x00) {
if (++blankCount > this.maxBlankFrames) {
this.errorMask |= 0x100000; // blank tape timeout
break; // kill the read loop
} else if (++imgIndex < imgLength) {
c = image[imgIndex]; // get next char frame
} else {
break; // at end of tape, kill the read loop
}
} else {
blankCount = 0;
cx = xlate[c];
if (cx < 0xFF) {
if (bufIndex < bufLength) {
buffer[bufIndex++] = cx; // store the ANSI character
if (++imgIndex < imgLength) {
c = image[imgIndex]; // get next char frame
} else {
break; // at end of tape, kill the read loop
}
} else {
this.imgIndex = imgIndex; // IOUnit buffer overflow
this.bcdSpaceForward(false);
imgIndex = this.imgIndex;
break; // kill the read loop
}
} else {
this.errorMask |= 0x10; // parity error
this.imgIndex = imgIndex;
this.bcdSpaceForward(false);
imgIndex = this.imgIndex;
break; // kill the read loop
}
}
} while (c < 0x80);
}
}
this.imgIndex = imgIndex;
this.bufIndex = bufIndex;
return bufIndex;
};
/**************************************/
B5500MagTapeDrive.prototype.bcdReadBackward = function bcdReadBackward(oddParity) {
/* Reads the next block from the .bcd tape (this.image) in a backward direction,
translating the character frames to ANSI character codes based on the translation
table "xlate". The translated data is stored in this.buffer. A block is terminated
when the next frame has its high-order bit set, or the beginning of the tape image
data is reached. The resulting buffer is always at least one character in length,
unless the block is a tapeMark or the end of the data has been reached.
oddParity 0=Alpha (even parity), 1=Binary (odd parity) read
Note that the characters are stored in this.buffer in ascending order as they are
being read backwards; thus the buffer is in reverse order with respect to how the
data will be stored in memory. The IOUnit will unravel this at finish.
Exits with the image index pointing to the first frame of THIS block (or at 0 if
at BOT). This arrangement allows changes between forward/reverse motion to work */
var blankCount = 0; // blank tape frame counter
var buffer = this.buffer; // IOUnit buffer
var bufLength = this.bufLength // IOUnit buffer length
var bufIndex = 0; // current IOUnit buffer offset
var c; // current character (tape image frame)
var cx; // current character translated to ASCII
var image = this.image; // tape image
var imgLength = this.imgLength; // tape image length
var imgIndex = this.imgIndex; // current tape image offset
var xlate = (oddParity ? this.bcdXlateInOdd : this.bcdXlateInEven);
if (imgIndex <= 0) {
this.setAtBOT(true);
this.errorMask |= 0x100000; // set blank-tape bit
} else {
if (this.atEOT) {
this.setAtEOT(false);
}
c = image[--imgIndex];
if (c == this.bcdTapeMark) {
this.errorMask |= 0x20; // EOF
} else {
do {
if (c == 0x00) {
if (++blankCount > this.maxBlankFrames) {
this.errorMask |= 0x100000; // blank tape timeout
break; // kill the read loop
} else if (imgIndex > 0) {
c = image[--imgIndex]; // get next char frame
} else {
break; // at end of tape, kill the read loop
}
} else {
blankCount = 0;
cx = xlate[c & 0x7F];
if (cx < 0xFF) {
if (bufIndex < bufLength) {
buffer[bufIndex++] = cx; // store the ANSI character
if (c >= 0x80) {
break; // at start of block, kill the read loop
} else if (imgIndex > 0) {
c = image[--imgIndex]; // get next char frame
} else {
break; // at start of tape, kill the read loop
}
} else {
this.imgIndex = imgIndex; // IOUnit buffer overflow
this.bcdSpaceBackward(false);
imgIndex = this.imgIndex;
break; // kill the read loop
}
} else {
this.errorMask |= 0x10; // parity error
this.imgIndex = imgIndex;
this.bcdSpaceBackward(false);
imgIndex = this.imgIndex;
break; // kill the read loop
}
}
} while (true);
}
}
this.imgIndex = imgIndex;
this.bufIndex = bufIndex;
return bufIndex;
};
/**************************************/
B5500MagTapeDrive.prototype.bcdWrite = function bcdWrite(oddParity) {
/* Writes the next block to the .bcd tape (this.image) in memory, translating
the character frames from ANSI character codes based on the translation
table "xlate". The translated data is stored at the current offset in
this.buffer. The start of a block is indicated by setting its high-order bit set.
oddParity 0=Alpha (even parity), 1=Binary (odd parity) write
Exits with the image index pointing beyond the last frame of the block (or beyond
the end of the image blob if at the end). Returns the number of characters written
to the IOUnit buffer */
var buffer = this.buffer; // IOUnit buffer
var bufLength = this.bufLength // IOUnit buffer length
var bufIndex = 0; // current IOUnit buffer offset
var image = this.image; // tape image
var imgLength = this.imgLength; // tape image length
var imgIndex = this.imgIndex; // current tape image offset
var xlate = (oddParity ? this.bcdXlateOutOdd : this.bcdXlateOutEven);
if (imgIndex >= imgLength) {
this.errorMask |= 0x04; // report not ready if beyond end of tape
} else {
if (this.atBOT) {
this.setAtBOT(false);
}
image[imgIndex++] = xlate[buffer[bufIndex++] & 0x7F] | 0x80;
while (bufIndex < bufLength) {
if (imgIndex >= imgLength) {
this.errorMask |= 0x04; // report not ready beyond end of tape
break;
} else {
image[imgIndex++] = xlate[buffer[bufIndex++] & 0x7F];
}
} // while
}
this.imgIndex = imgIndex;
this.bufIndex = bufIndex;
if (imgIndex > this.imgTopIndex) {
this.imgTopIndex = imgIndex;
}
return bufIndex;
};
/**************************************/
B5500MagTapeDrive.prototype.tapeDriveBeforeUnload = function tapeDriveBeforeUnload(ev) {
var msg = "Closing this window will make the device unusable.\n" +
"Suggest you stay on the page and minimize this window instead";
ev.preventDefault();
ev.returnValue = msg;
return msg;
};
/**************************************/
B5500MagTapeDrive.prototype.tapeDriveOnLoad = function tapeDriveOnLoad() {
/* Initializes the reader window and user interface */
var that = this;
this.doc = this.window.document;
this.doc.title = "retro-B5500 " + this.mnemonic;
this.progressBar = this.$$("MTProgressBar");
this.reelIcon = this.$$("MTReel");
this.window.addEventListener("beforeunload", this.tapeDriveBeforeUnload, false);
this.tapeState = this.tapeLocal; // setTapeUnloaded() requires it to be in local
this.atBOT = true; // and also at BOT
this.setTapeUnloaded();
this.$$("MTUnloadBtn").addEventListener("click", function unloadBtn(ev) {
that.MTUnloadBtn_onclick(ev);
}, false);
this.$$("MTLoadBtn").addEventListener("click", function loadBtn(ev) {
that.MTLoadBtn_onclick(ev);
}, false);
this.$$("MTRemoteBtn").addEventListener("click", function remoteBtn(ev) {
that.MTRemoteBtn_onclick(ev);
}, false);
this.$$("MTLocalBtn").addEventListener("click", function localBtn(ev) {
that.MTLocalBtn_onclick(ev);
}, false);
this.$$("MTWriteRingBtn").addEventListener("click", function writeRingBtn(ev) {
that.MTWriteRingBtn_onclick(ev);
}, false);
this.$$("MTRewindBtn").addEventListener("click", function rewindBtn(ev) {
that.MTRewindBtn_onclick(ev);
}, false);
this.progressBar.addEventListener("click", function progressClick(ev) {
that.MTProgressBar_onclick(ev);
}, false);
};
/**************************************/
B5500MagTapeDrive.prototype.read = function read(finish, buffer, length, mode, control) {
/* Initiates a read operation on the unit. If the drive is busy or not ready,
returns those conditions. Otherwise, attempts to read the next block from the tape.
mode 0=Alpha (even parity), 1=Binary (odd parity) read
control 0=forward, 1=backward read
*/
var count; // number of characters read into IOUnit buffer
var imgCount = this.imgIndex; // number of characters passed on tape
var inches = 0; // block length including gap [inches]
var residue; // residual characters in last word read
this.errorMask = 0;
if (this.busy) {
finish(0x01, 0); // report unit busy
} else if (!this.ready) {
finish(0x04, 0); // report unit not ready
} else {
this.busy = true;
this.buffer = buffer;
this.bufLength = length;
this.bufIndex = 0;
if (control) {
count = this.bcdReadBackward(mode);
residue = 7 - count % 8;
imgCount -= this.imgIndex;
inches = -imgCount/this.density - this.gapLength;
this.tapeInches += inches;
if (this.atEOT && this.tapeInches < this.imgEOTInches) {
this.setAtEOT(false);
}
} else {
count = this.bcdReadForward(mode);
residue = count % 8;
imgCount = this.imgIndex - imgCount;
inches = imgCount/this.density + this.gapLength;
this.tapeInches += inches;
if (!this.atEOT && this.tapeInches > this.imgEOTInches) {
this.setAtEOT(true);
}
}
this.buildErrorMask(residue);
this.timer = setCallback(function readDelay() {
this.busy = false;
finish(this.errorMask, count);
}, this, (imgCount/this.charsPerSec + this.startStopTime)*1000 +
this.initiateStamp - new Date().getTime());
this.spinReel(inches);
if (this.tapeInches < this.imgMaxInches) {
this.progressBar.value = this.imgMaxInches - this.tapeInches;
} else {
this.progressBar.value = 0;
}
this.buffer = null;
}
//console.log(this.mnemonic + " read: c=" + control + ", length=" + length + ", mode=" + mode +
// ", count=" + count + ", inches=" + this.tapeInches +
// ", index=" + this.imgIndex + ", mask=" + this.errorMask.toString(8));
//console.log(String.fromCharCode.apply(null, buffer.subarray(0, 80)).substring(0, count));
};
/**************************************/
B5500MagTapeDrive.prototype.space = function space(finish, length, control) {
/* Initiates a space operation on the unit. If the drive is busy or not ready,
returns those conditions. Otherwise, attempts to space over the next block
from the tape. Parity errors are ignored.
control 0=forward, 1=backward space
*/
var imgCount = this.imgIndex; // number of characters passed on tape
var inches = 0; // block length including gap [inches]
this.errorMask = 0;
if (this.busy) {
finish(0x01, 0); // report unit busy
} else if (!this.ready) {
finish(0x04, 0); // report unit not ready
} else {
this.busy = true;
if (control) {
this.bcdSpaceBackward(true);
imgCount -= this.imgIndex;
inches = -imgCount/this.density - this.gapLength;
this.tapeInches += inches;
if (this.atEOT && this.tapeInches < this.imgEOTInches) {
this.setAtEOT(false);
}
} else {
this.bcdSpaceForward(true);
imgCount = this.imgIndex - imgCount;
inches = imgCount/this.density + this.gapLength;
this.tapeInches += inches;
if (!this.atEOT && this.tapeInches > this.imgEOTInches) {
this.setAtEOT(true);
}
}
this.buildErrorMask(0);
this.timer = setCallback(function readDelay() {
this.busy = false;
finish(this.errorMask, 0);
}, this, (imgCount/this.charsPerSec + this.startStopTime)*1000 +
this.initiateStamp - new Date().getTime());
this.spinReel(inches);
if (this.tapeInches < this.imgMaxInches) {
this.progressBar.value = this.imgMaxInches - this.tapeInches;
} else {
this.progressBar.value = 0;
}
}
//console.log(this.mnemonic + " space: c=" + control + ", length=" + length +
// ", count=" + imgCount + ", inches=" + this.tapeInches +
// ", index=" + this.imgIndex + ", mask=" + this.errorMask.toString(8));
};
/**************************************/
B5500MagTapeDrive.prototype.write = function write(finish, buffer, length, mode, control) {
/* Initiates a write operation on the unit. If the drive is busy, not ready or has
no write ring, returns those conditions. Otherwise, attempts to write the next block
to the tape. mode 0=Alpha (even parity), 1=Binary (odd parity) write */
var count; // number of characters read into IOUnit buffer
var imgCount = this.imgIndex; // number of characters passed on tape
var inches = 0; // block length including gap [inches]
var residue; // residual characters in last word read
this.errorMask = 0;
if (this.busy) {
finish(0x01, 0); // report unit busy
} else if (!this.ready) {
finish(0x04, 0); // report unit not ready
} else if (!this.writeRing) {
finish(0x50, 0); // RD bits 26 & 28 => no write ring, don't return Mod III bits
} else {
this.busy = true;
this.buffer = buffer;
this.bufLength = length;
this.bufIndex = 0;
count = this.bcdWrite(mode);
residue = count % 8;
imgCount = this.imgIndex - imgCount;
inches = imgCount/this.density + this.gapLength;
this.tapeInches += inches;
if (!this.atEOT && this.tapeInches > this.imgEOTInches) {
this.setAtEOT(true);
}
this.imgWritten = true;
this.buildErrorMask(residue);
this.timer = setCallback(function writeDelay() {
this.busy = false;
finish(this.errorMask, count);
}, this, (imgCount/this.charsPerSec + this.startStopTime)*1000 +
this.initiateStamp - new Date().getTime());
this.spinReel(inches);
if (this.tapeInches < this.imgMaxInches) {
this.progressBar.value = this.imgMaxInches - this.tapeInches;
} else {
this.progressBar.value = 0;
}
this.buffer = null;
}
//console.log(this.mnemonic + " write: c=" + control + ", length=" + length + ", mode=" + mode +
// ", count=" + count + ", inches=" + this.tapeInches +
// ", index=" + this.imgIndex + ", mask=" + this.errorMask.toString(8));
//console.log(String.fromCharCode.apply(null, buffer.subarray(0, 80)).substring(0, count));
};
/**************************************/
B5500MagTapeDrive.prototype.erase = function erase(finish, length) {
/* Initiates an erase operation on the unit. If the drive is busy, not ready,
or has no write ring, then returns those conditions. Otherwise, does nothing
to the tape image, as lengths of blank tape less than 9 feet in length are
not "seen" by the I/O Unit. Delays an appropriate amount of time for the
length of the erasure */
var inches; // erase length [inches]
this.errorMask = 0;
if (this.busy) {
finish(0x01, 0); // report unit busy
} else if (!this.ready) {
finish(0x04, 0); // report unit not ready
} else if (!this.writeRing) {
finish(0x50, 0); // RD bits 26 & 28 => no write ring, don't return Mod III bits
} else {
this.busy = true;
inches = length/this.density;
this.tapeInches += inches;
if (!this.atEOT && this.tapeInches > this.imgEOTInches) {
this.setAtEOT(true);
}
this.imgWritten = true;
this.buildErrorMask(0);
this.timer = setCallback(function eraseDelay() {
this.busy = false;
finish(this.errorMask, 0);
}, this, (length/this.charsPerSec + this.startStopTime)*1000 +
this.initiateStamp - new Date().getTime());
this.spinReel(inches);
if (this.tapeInches < this.imgMaxInches) {
this.progressBar.value = this.imgMaxInches - this.tapeInches;
} else {
this.progressBar.value = 0;
}
}
//console.log(this.mnemonic + " erase: c=" + control + ", length=" + length +
// ", inches=" + this.tapeInches +
// ", index=" + this.imgIndex + ", mask=" + this.errorMask.toString(8));
};
/**************************************/
B5500MagTapeDrive.prototype.rewind = function rewind(finish) {
/* Initiates a rewind operation on the unit. If the drive is busy or not ready,
returns those conditions. Otherwise, makes the drive not-ready, delays for an
appropriate amount of time depending on how far up-tape we are, then readies the
unit again */
this.errorMask = 0;
if (this.busy) {
finish(0x01, 0); // report unit busy
} else if (!this.ready) {
finish(0x04, 0); // report unit not ready
} else {
this.tapeRewind(true);
this.buildErrorMask(0);
finish(this.errorMask, 0);
}
//console.log(this.mnemonic + " rewind: mask=" + this.errorMask.toString(8));
};
/**************************************/
B5500MagTapeDrive.prototype.readCheck = function readCheck(finish, length, control) {
/* Initiates a read check operation on the unit */
finish(0x04, 0); // report unit not ready
};
/**************************************/
B5500MagTapeDrive.prototype.readInterrogate = function readInterrogate(finish, control) {
/* Initiates a read interrogate operation on the unit */
finish(0x04, 0); // report unit not ready
};
/**************************************/
B5500MagTapeDrive.prototype.writeInterrogate = function writeInterrogate(finish, control) {
/* Initiates a write interrogate operation on the unit. This is actually a write
of zero length, typically used to determine ready and BOT/EOT status for the drive */
this.errorMask = 0;
if (this.busy) {
finish(0x01, 0); // report unit busy
} else if (!this.ready) {
finish(0x04, 0); // report unit not ready
} else {
if (this.writeRing) {
this.buildErrorMask(0);
} else {
this.errorMask |= 0x50; // RD bits 26 & 28 => no write ring, don't return Mod III bits
}
finish(this.errorMask, 0);
}
//console.log(this.mnemonic + " writeInterrogate: c=" + control + ", mask=" + this.errorMask.toString(8));
};
/**************************************/
B5500MagTapeDrive.prototype.shutDown = function shutDown() {
/* Shuts down the device */
if (this.timer) {
clearCallback(this.timer);
}
this.window.removeEventListener("beforeunload", this.tapeDriveBeforeUnload, false);
this.window.close();
};