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Cleaned up management of unused PSW bits

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This commit is contained in:
Jeff Parsons 2016-12-04 16:23:37 -08:00 • committed by Jeff Parsons
commit 1e1db7b78e
24 changed files with 574 additions and 530 deletions
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22
modules/pdp11/lib/defines.js
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@ -124,8 +124,20 @@ var PDP11 = {
/*
* CPU model numbers (supported)
*
* The 11/20 includes the 11/10, which is not identified separately because there was
* nothing functionally different about it.
*
* The 11/40 added the MODE bits to the PSW (but only KERNEL=00 and USER=11) and 18-bit
* addressing via an MMU; there was still only one register set.
*
* The 11/45 added REGSET bit to the PSW (along with the second register set), and added
* SUPERVISOR=01 to the set of modes.
*
* The 11/70 added 22-bit addressing and corresponding extensions to the MMU.
*/
MODEL_1120: 1120,
MODEL_1140: 1140,
MODEL_1145: 1145,
MODEL_1170: 1170,
@ -169,9 +181,13 @@ var PDP11 = {
PRI: 0x00E0, // bits 5-7 (000340) Priority
UNUSED: 0x0700, // bits 8-10 (003400) UNUSED
/*
* PSW bits above this point are unused on 11/20-class machines
* The REGSET bit (and the alternate register set stored in regsAlt) came into existence
* with the 11/45; (ie, they were not present on the 11/10, 11/20, or 11/40).
*/
REGSET: 0x0800, // bit 11 (004000) Register Set
/*
* The MODE bits came into existence with the 11/40 (eg, not present on the 11/10 or 11/20).
*/
PMODE: 0x3000, // bits 12-13 (030000) Prev Mode (see PDP11.MODE)
CMODE: 0xC000, // bits 14-15 (140000) Curr Mode (see PDP11.MODE)
SHIFT: {
@ -266,6 +282,7 @@ var PDP11 = {
IRQ_DELAY: 0x0001, // incremented until it becomes IRQ (set by SPL and traps)
IRQ: 0x0002, // time to call checkInterrupts()
IRQ_MASK: 0x0003,
DEBUGGER: 0x0004, // set if the Debugger wants to perform checks
WAIT: 0x0008, // WAIT operation in progress
PRESERVE: 0x000F, // OPFLAG bits to preserve prior to the next instruction
TRAP_TF: 0x0010, // aka PDP11.PSW.TF (WARNING: do not change this bit, or you will likely break opRTI())
@ -873,8 +890,7 @@ PDP11.ACCESS.UPDATE_WORD = PDP11.ACCESS.WORD | PDP11.ACCESS.UPDATE; // forme
PDP11.ACCESS.UPDATE_BYTE = PDP11.ACCESS.BYTE | PDP11.ACCESS.UPDATE; // formerly MODIFY_BYTE (1 | 2 | 4)
/*
* PSW arithmetic flags are NOT stored directly into the PSW register; they are maintained across separate
* flag registers.
* PSW arithmetic flags are NOT stored directly into the PSW register; they are maintained across separate flag registers.
*/
PDP11.PSW.FLAGS = (PDP11.PSW.NF | PDP11.PSW.ZF | PDP11.PSW.VF | PDP11.PSW.CF);