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Refactored Task code into separate files for readability; added breakpoint support and basic Memory window to debugger. Initial implementation (mostly stubs) of Disk hardware and Tasks.

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This commit is contained in:
Josh Dersch
2015-09-14 11:27:16 -07:00
parent 24d7a5a8fe
commit 08d6063def
11 changed files with 1469 additions and 941 deletions
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79
Contralto/IO/DiskController.cs
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@@ -41,7 +41,12 @@ namespace Contralto.IO
{
_kCom = value;
//
// Read control bits (pg. 47 of hw manual)
_xferOff = (_kCom & 0x10) == 0x10;
_wdInhib = (_kCom & 0x08) == 0x08;
_bClkSource = (_kCom & 0x04) == 0x04;
_wffo = (_kCom & 0x02) == 0x02;
_sendAdr = (_kCom & 0x01) == 0x01;
}
}
@@ -56,6 +61,36 @@ namespace Contralto.IO
get { return _recMap[_recNo]; }
}
public int Cylinder
{
get { return _cylinder; }
}
public int SeekCylinder
{
get { return _destCylinder; }
}
public int Head
{
get { return _head; }
}
public int Sector
{
get { return _sector; }
}
public int Drive
{
get { return 0; }
}
public double ClocksUntilNextSector
{
get { return _sectorClocks - _elapsedSectorTime; }
}
public void Reset()
{
ClearStatus();
@@ -100,7 +135,7 @@ namespace Contralto.IO
{
_cylinder++;
}
else
else if (_cylinder > _destCylinder)
{
_cylinder--;
}
@@ -113,6 +148,33 @@ namespace Contralto.IO
}
}
}
//
// Select data word based on elapsed time in this sector, if data transfer is not inhibited.
// On a new word, wake up the disk word task if not inhibited
// TODO: the exact mechanics of this are still kind of mysterious.
// Things to examine the schematics / uCode for:
// - Use of WFFO bit -- is this related to the "sync word" that the docs mention?
// - how does WFFO work -- I assume the "1 bit" mentioned in the docs indicates the MFM bit
// and indicates the start of the next data word (or is at least used to wait for the next
// data word)
// - How does the delaying work
// The microcode word-copying code works basically as:
// On wakeup:
// - read word, store into memory.
// - block task (remove wakeup)
// - task switch (let something else run)
// - repeat until all words read
// that is, the microcode expects to be woken up on a per-word basis, and it only reads in one word
// per wakeup.
//
// pseudocode so far:
// if (elapsed word time > word time)
// {
// elapsed word time = 0 (modulo remainder)
// _kData = next word
// if (!_wdInhib) DiskSectorTask.Wakeup();
// }
}
public void ClearStatus()
@@ -148,16 +210,16 @@ namespace Contralto.IO
// sanity check: see if SENDADR bit is set, if not we'll signal an error (since I'm trusting that
// the official Xerox uCode is doing the right thing, this will help ferret out emulation issues.
// eventually this can be removed.)
if ((_kCom & 0x1) != 1)
if (!_sendAdr)
{
throw new InvalidOperationException("STROBE while SENDADR bit of KCOMM not 1. Unexpected.");
throw new InvalidOperationException("STROBE while SENDADR bit of KCOM not 1. Unexpected.");
}
_destCylinder = (_kData & 0x0ff8) >> 3;
// set "seek fail" bit based on selected cylinder (if out of bounds) and do not
// commence a seek if so.
if (_destCylinder < 203)
if (_destCylinder > 202)
{
_kStat |= 0x0080;
}
@@ -202,6 +264,13 @@ namespace Contralto.IO
0, 2, 3, 1
};
// KCOM bits
private bool _xferOff;
private bool _wdInhib;
private bool _bClkSource;
private bool _wffo;
private bool _sendAdr;
// Current disk position
private int _cylinder;
private int _destCylinder;