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Some PDP-10 disassembler clean-up

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This commit is contained in:
Jeff Parsons 2017-02-25 21:19:41 -08:00 • committed by Jeff Parsons
commit 3e30bde786
3 changed files with 94 additions and 78 deletions
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43
modules/pdp10/lib/defines.js
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@ -101,7 +101,37 @@ var PDP10 = {
DATA_LIMIT: Math.pow(2, 36),
/*
* Opcode definitions
* PDP-10 opcodes are 36-bit values, most of which use the following layout:
*
* 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
* O O O O O O O M M A A A A I X X X X Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y
*
* or using modern bit-numbering:
*
* 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
* 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* O O O O O O O M M A A A A I X X X X Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y
*
* where OOOOOOOMM represents the operation, and MM (if used) represents the mode:
*
* Mode Suffix Source Destination
* ---- ------ ----- -----------
* 0: BASIC None E AC
* 1: IMMEDIATE I 0,E AC
* 2: MEMORY M AC E
* 3: SELF S E E (and AC if A is non-zero)
*
* Input-output instructions look like:
*
* 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
* 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* 1 1 1 D D D D D D D O O O I X X X X Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y
*
* Bits 0-22 (I,X,Y) contain what we call a "reference address" (R), which is used to
* calculate the "effective address" (E). To determine E from R, we must extract I, X,
* and Y from R, set E to Y, then add [X] to E if X is non-zero. If I is zero, then
* we're done; otherwise, we must set set R to [E] and repeat the process.
*/
OPCODE: {
OPMASK: 0o77700, // operation mask
@ -115,11 +145,12 @@ var PDP10 = {
FNMASK: 0o17, // accumulator/function mask (after shift)
IOSHIFT: Math.pow(2, 26), // input-output device code shift
IOMASK: 0o177, // input-output device code mask (after shift)
SHIFT: Math.pow(2, 27), // operation code shift
Y_MASK: 0o777777,
X_SHIFT: 18,
X_MASK: 0o17,
I_BIT: 0o20000000,
O_SHIFT: Math.pow(2, 27), // operation shift
O_MASK: 0o777, // operation mask (after shift)
I_BIT: 0o20000000, // indirect bit
X_SHIFT: 18, // X shift
X_MASK: 0o17, // X mask (after shift)
Y_MASK: 0o777777, // Y mask
HALT: 0o5304 // operation code for HALT
},