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More 8080 improvements, including some initial "Fake CP/M" support

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This commit is contained in:
Jeff Parsons 2016-04-27 08:28:52 -07:00
commit 5b6f6756a2
25 changed files with 1051 additions and 842 deletions
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37
modules/pcjs/lib/bus.js
View file

@ -78,7 +78,7 @@ function Bus(parmsBus, cpu, dbg)
this.cpu = cpu;
this.dbg = dbg;
this.nBusWidth = parmsBus['buswidth'] || 20;
this.nBusWidth = parmsBus['busWidth'] || 20;
/*
* Compute all Bus memory block parameters, based on the width of the bus.
@ -93,8 +93,8 @@ function Bus(parmsBus, cpu, dbg)
*
* iBlock & this.nBlockMask
*
* Similarly, we mask addresses with busMask to enforce "A20 wrap" on 20-bit busses.
* For larger busses, A20 wrap can be simulated by either clearing bit 20 of busMask or by
* Similarly, we mask addresses with busMask to enforce "A20 wrap" on 20-bit buses.
* For larger buses, A20 wrap can be simulated by either clearing bit 20 of busMask or by
* changing all the block entries for the 2nd megabyte to match those in the 1st megabyte.
*
* Bus Property Old hard-coded values (when nBusWidth was always 20)
@ -354,16 +354,16 @@ Bus.prototype.powerUp = function(data, fRepower)
* allocations, etc.
*
* We've relaxed some of the original requirements (ie, that addresses must start at a
* block-granular address, or that sizes must be equal to exactly one or more blocks), because
* machines with large block sizes can make it impossible to load certain ROMs at at their
* required addresses.
* block-granular address, or that sizes must be equal to exactly one or more blocks),
* because machines with large block sizes can make it impossible to load certain ROMs at
* their required addresses. Every allocation still allocates a whole number of blocks.
*
* Even so, Bus memory management does NOT provide a general-purpose heap. Most memory
* allocations occur during machine initialization and never change. The only notable
* exception is the Video frame buffer, which ranges from 4Kb (MDA) to 16Kb (CGA) to
* 32Kb/64Kb/128Kb (EGA), and only the EGA changes its buffer address post-initialization.
* allocations occur during machine initialization and never change. In particular, there
* is NO support for removing partial-block allocations. Typically, the only region that
* changes post-initialization is the Video buffer, and only in the EGA/VGA implementation.
*
* Each Memory block keeps track of a single address (addr) and length (used), indicating
* Each Memory block keeps track of a start address (addr) and length (used), indicating
* the used space within the block; any free space that precedes or follows that used space
* can be allocated later, by simply extending the beginning or ending of the previously used
* space. However, any holes that might have existed between the original allocation and an
@ -380,17 +380,18 @@ Bus.prototype.addMemory = function(addr, size, type, controller)
{
var iBlock = addr >>> this.nBlockShift;
while (size > 0 && iBlock < this.aMemBlocks.length) {
var block = this.aMemBlocks[iBlock];
var addrBlock = iBlock * this.nBlockSize;
var sizeBlock = size > this.nBlockSize? this.nBlockSize : size;
var sizeBlock = this.nBlockSize - (addr - addrBlock);
if (sizeBlock > size) sizeBlock = size;
if (block && block.size) {
if (block.type == type && block.controller == controller) {
/*
* Where there is already a block with a non-zero size, we can allow the allocation only if:
* Where there is already a similar block with a non-zero size, we allow the allocation only if:
*
* 1) addr + size <= block.addr (the request precedes the used portion of the current block)
* or:
* 1) addr + size <= block.addr (the request precedes the used portion of the current block), or
* 2) addr >= block.addr + block.used (the request follows the used portion of the current block)
*/
if (addr + size <= block.addr) {
@ -402,17 +403,19 @@ Bus.prototype.addMemory = function(addr, size, type, controller)
var sizeAvail = block.size - (addr - addrBlock);
if (sizeAvail > size) sizeAvail = size;
block.used = addr - block.addr + sizeAvail;
size -= sizeAvail;
addr = addrBlock + this.nBlockSize;
size -= sizeAvail;
iBlock++;
continue;
}
}
return this.reportError(Bus.ERROR.ADD_MEM_INUSE, addr, size);
}
var blockOld = this.aMemBlocks[iBlock];
var blockNew = new Memory(addr, sizeBlock, this.nBlockSize, type, controller);
blockNew.copyBreakpoints(this.dbg, blockOld);
blockNew.copyBreakpoints(this.dbg, block);
this.aMemBlocks[iBlock++] = blockNew;
addr = addrBlock + this.nBlockSize;
size -= sizeBlock;
}

2
modules/pcjs/lib/computer.js
View file

@ -195,7 +195,7 @@ function Computer(parmsComputer, parmsMachine, fSuspended) {
/*
* Initialize the Bus component
*/
this.bus = new Bus({'id': this.idMachine + '.bus', 'buswidth': this.nBusWidth}, this.cpu, this.dbg);
this.bus = new Bus({'id': this.idMachine + '.bus', 'busWidth': this.nBusWidth}, this.cpu, this.dbg);
/*
* Iterate through all the components and connect them to the Control Panel, if any

6
modules/pcjs/lib/rom.js
View file

@ -305,6 +305,12 @@ ROM.prototype.copyROM = function()
this.setReady();
}
else if (this.abROM && this.bus) {
/*
* If no explicit size was specified, then use whatever the actual size is.
*/
if (!this.sizeROM) {
this.sizeROM = this.abROM.length;
}
if (this.abROM.length != this.sizeROM) {
/*
* Note that setError() sets the component's fError flag, which in turn prevents setReady() from