The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Assembly Language’ Category

« Previous Entries

Some lesser known achievements of Phil (Philip A.) Kaufman

Posted by jpluimers on 2026/02/10

Sometimes Wikipedia entries are way too short, for instance Philip A. Kaufman – Wikipedia, who in 1992 – at the age of around 50 – died way to early, does not do justice to his time at Intel.

His name rang a bell when searching for early Intel 8087 documentation distributed via LISTSERV, so below is a bit more information on Phil.

True, his life after Intel was very important especially on the front of electronic design automation. That in fact sparked the posthumous instantiation of the Phil Kaufman Award which you can read for instance at [Wayback/Archive] The Phil Kaufman Award Dinner Is Later this Month. Who Was Phil Kaufman? – Breakfast Bytes – Cadence Blogs – Cadence Community.

After his floating-point endeavours at Intel and the IEEE, he was also very instrumental at Intel in finding another big market for silicon: network controller chips (and getting the Ethernet standard going: think DIX (Digital/Intel/Xerox) [Wayback/Archive] Ethernet Blue Book (1980) which was named that way earlier than the PostScript Blue Book (1986) and CD Blue Book (1986)).

This period is very well described in the [Wayback/Archive] 1988 Computer History Museum interview of Phil Kaufman by James L. Pelkey (via [Wayback/Archive] Phil Kaufman | History of Computer Communications).

Back to floating point: Phil’s post from 1987 way better describes what early processor technologies at Intel he was involved with than the above links. That period was instrumental in getting IEEE_754-1985 going (it was released way after the 8087!) and still shapes the floating point aspects of almost any CPU from any vendor today so I quote it in full from [Wayback/Archive] Info-IBMPC V6 #59:

Read the rest of this entry »

Posted in 8086, 8087, 8087, 8088, Algorithms, Assembly Language, Development, Floating point handling, History, x86 | Leave a Comment »

Bit by Bit – Exploring Low-Level Programming on the Apple IIe | decuser’s blog

Posted by jpluimers on 2026/02/05

At the time of posting [Wayback/Archive] Bit by Bit – Exploring Low-Level Programming on the Apple IIe | decuser’s blog in 20251010, four episodes were up at [Wayback/Archive] Bit by Bit – Exploring low-level programming with an Apple IIe – YouTube which at the time of archiving at the end of October 2025 already got 10 episodes.

Hopefully by now – some 2 months later – the list has grown even further.

Via [Wayback/Archive] Bit by Bit – Exploring Low-Level Programming on the Apple IIe | Applefritter who explains further than the blog post:

Read the rest of this entry »

Posted in //e, 6502, 6502 Assembly, Apple, Assembly Language, Development, History, Power User, Retrocomputing, Software Development | Leave a Comment »

Online x86 and x64 Intel Instruction Assembler

Posted by jpluimers on 2025/11/25

[Wayback/Archive] Online x86 and x64 Intel Instruction Assembler

The source starts in these two files:

Read the rest of this entry »

Posted in Assembly Language, Conference Topics, Conferences, Development, Event, Software Development, x64, x86 | Leave a Comment »

What Every Programmer Should Know about How CPUs Work • Matt Godbolt • GOTO 2024 – YouTube

Posted by jpluimers on 2025/09/10

[Wayback/Archive] What Every Programmer Should Know about How CPUs Work • Matt Godbolt • GOTO 2024 – YouTube

Main takeaways for me:

  • CPU pipelines have grown a lot longer than I was aware off
  • there are many more internal registers than I was anticipating
  • clever ways to convert if statements to non-jumps

--jeroen

Posted in .NET, Assembly Language, C, C#, C++, Delphi, Development, Python, Scripting, Software Development | Leave a Comment »

A signal of the future WebAssembly/emscripten is giving us: a database served on a static web page

Posted by jpluimers on 2025/04/17

From a quite a while back; apparently it ended up in the drafts in stead of the blog queue:

[Wayback/Archive] Ian Miell on Twitter: “A signal of the future WebAssembly/emscripten is giving us: a database served on a static web page: … The possibilities are dizzying. Also, I’ve thought for a while that if I had to put money on it, SQLite will outlast every other database out there.”

The combination of Emscripten and WebAssembly is cool as it allows you to run C/C++ based code in most Web Browsers at near-native speed (though the standard is open and can just as easily outside that realm).

[Wayback/Archive] Hosting SQLite databases on Github Pages – (or any static file hoster) – phiresky’s blog:

Read the rest of this entry »

Posted in Assembly Language, Database Development, Development, JavaScript/ECMAScript, Scripting, Software Development, SQLite, Web Development, WebAssembly | Leave a Comment »

Run Windows 3.1 in True-Colour Full HD: GitHub – PluMGMK/vbesvga.drv: Modern Generic SVGA driver for Windows 3.1

Posted by jpluimers on 2025/04/09

This is soooo cool: [Wayback/Archive] GitHub – PluMGMK/vbesvga.drv: Modern Generic SVGA driver for Windows 3.1

Modern Generic SVGA driver for Windows 3.1
This is a rewrite of the Windows 3.1 SVGA driver, designed to support ALL available 8-bit, 16-bit, 24-bit or 32-bit graphic modes on any system providing the VESA BIOS Extensions (hence the VBE in the name). It is based on the Video 7 SVGA driver included in the Win16 Driver Development Kit, with most of the hardware-specific code gutted out, and with support added for multi-byte pixels.

Related:

It reminds me of other endevours to keep retro-software easy to use: Read the rest of this entry »

Posted in Assembly Language, Delphi, Delphi 1, Development, Power User, Software Development, Windows, Windows 3.11, x86 | Leave a Comment »

For my link archive: Counting the leading zeroes and ones in a binary number with C#

Posted by jpluimers on 2025/03/13

From a while back, but still interesting:

  1. [Wayback/Archive] Counting the leading zeroes in a binary number with C#
  2. [Wayback/Archive] c# – Getting the number of leading 1 bits – Stack Overflow (thanks [Wayback/Archive] Barry Kelly and [Wayback/Archive] SoapBox)

Especially the first link explains the algorithm very well and is similar to links referred to from the Stack Overflow question as it is based on counting ones (and leading ones are basically leading zeros but bit-inverted).

It also explains a cool thing for leading zeros: modern CPU have instructions which .NET Core.

Read the rest of this entry »

Posted in .NET, AArch64/arm64, Algorithms, ARM, Assembly Language, C, C#, C++, Delphi, Development, Software Development, x64, x86 | Tagged: , , | Leave a Comment »

Raymond Chen on The AArch64 processor (aka arm64) in many parts

Posted by jpluimers on 2025/01/14

For my link archive: below a series of articles my Raymond Chen on “The AArch64 processor (aka arm64)” in the order of appearance from a few years back and still very relevant today.

It is part of a few more series on processors that (were) supported by Windows. A good reference to find which version supported which processor architecture is the tables in List of Microsoft Windows versions – Wikipedia.

Read the rest of this entry »

Posted in AArch64/arm64, ARM, Assembly Language, Development, History, MIPS R4000, PowerPC, Software Development, The Old New Thing, Windows Development, x64, x86 | Leave a Comment »

x86 assembly – Difference between JE/JNE and JZ/JNZ – Stack Overflow

Posted by jpluimers on 2024/12/25

This brought back memories of some 40 years ago during my first steps learning x86 assembly language, realising the first comment: [Wayback/Archive] assembly – Difference between JE/JNE and JZ/JNZ – Stack Overflow

Q

In x86 assembly code, are JE and JNE exactly the same as JZ and JNZ?

C

Long answer: yes.

C

TL:DR: same machine operation, different semantic meaning. Just like jb / jc / jnae all testing CF=1. See felixcloutier.com/x86/jcc

Merry X-mas everyone!

And thanks [Wayback/Archive] Daniel Hanrahan for asking, [Wayback/Archive] Hans Passant and [Wayback/Archive] Peter Cordes for commenting.

Be sure to read the rest of the comments and answers to read on the WHY these instructions are the same. That insight made me realise I was finally understanding the x86 architecture at a deeper level.

Related:

  • [WaybackSave/Archive] Intel® 64 and IA-32 Architectures Software Developer’s Manual Combined Volumes 2A, 2B, 2C, and 2D: Instruction Set Reference, A-Z
  • [Wayback/Archive] Jcc — Jump if Condition Is Met

    Sorted by Opcode column (with a little bit of help from Excel, Notepad++ and [Wayback/Archive] HTML Tables generator – TablesGenerator.com; then bolded or italicised the Description column of equivalent entries:

    Opcode Instruction Op/En 64-Bit Mode Compat/Leg Mode Description
    0F 80 cd JO rel32 D Valid Valid Jump near if overflow (OF=1).
    0F 80 cw JO rel16 D N.S. Valid Jump near if overflow (OF=1). Not supported in 64-bit mode.
    0F 81 cd JNO rel32 D Valid Valid Jump near if not overflow (OF=0).
    0F 81 cw JNO rel16 D N.S. Valid Jump near if not overflow (OF=0). Not supported in 64-bit mode.
    0F 82 cd JB rel32 D Valid Valid Jump near if below (CF=1).
    0F 82 cd JC rel32 D Valid Valid Jump near if carry (CF=1).
    0F 82 cd JNAE rel32 D Valid Valid Jump near if not above or equal (CF=1).
    0F 82 cw JB rel16 D N.S. Valid Jump near if below (CF=1). Not supported in 64-bit mode.
    0F 82 cw JC rel16 D N.S. Valid Jump near if carry (CF=1). Not supported in 64-bit mode.
    0F 82 cw JNAE rel16 D N.S. Valid Jump near if not above or equal (CF=1). Not supported in 64-bit mode.
    0F 83 cd JAE rel32 D Valid Valid Jump near if above or equal (CF=0).
    0F 83 cd JNB rel32 D Valid Valid Jump near if not below (CF=0).
    0F 83 cd JNC rel32 D Valid Valid Jump near if not carry (CF=0).
    0F 83 cw JAE rel16 D N.S. Valid Jump near if above or equal (CF=0). Not supported in 64-bit mode.
    0F 83 cw JNB rel16 D N.S. Valid Jump near if not below (CF=0). Not supported in 64-bit mode.
    0F 83 cw JNC rel16 D N.S. Valid Jump near if not carry (CF=0). Not supported in 64-bit mode.
    0F 84 cd JE rel32 D Valid Valid Jump near if equal (ZF=1).
    0F 84 cd JZ rel32 D Valid Valid Jump near if 0 (ZF=1).
    0F 84 cd JZ rel32 D Valid Valid Jump near if 0 (ZF=1).
    0F 84 cw JE rel16 D N.S. Valid Jump near if equal (ZF=1). Not supported in 64-bit mode.
    0F 84 cw JZ rel16 D N.S. Valid Jump near if 0 (ZF=1). Not supported in 64-bit mode.
    0F 84 cw JZ rel16 D N.S. Valid Jump near if 0 (ZF=1). Not supported in 64-bit mode.
    0F 85 cd JNE rel32 D Valid Valid Jump near if not equal (ZF=0).
    0F 85 cd JNZ rel32 D Valid Valid Jump near if not zero (ZF=0).
    0F 85 cw JNE rel16 D N.S. Valid Jump near if not equal (ZF=0). Not supported in 64-bit mode.
    0F 85 cw JNZ rel16 D N.S. Valid Jump near if not zero (ZF=0). Not supported in 64-bit mode.
    0F 86 cd JBE rel32 D Valid Valid Jump near if below or equal (CF=1 or ZF=1).
    0F 86 cd JNA rel32 D Valid Valid Jump near if not above (CF=1 or ZF=1).
    0F 86 cw JBE rel16 D N.S. Valid Jump near if below or equal (CF=1 or ZF=1). Not supported in 64-bit mode.
    0F 86 cw JNA rel16 D N.S. Valid Jump near if not above (CF=1 or ZF=1). Not supported in 64-bit mode.
    0F 87 cd JA rel32 D Valid Valid Jump near if above (CF=0 and ZF=0).
    0F 87 cd JNBE rel32 D Valid Valid Jump near if not below or equal (CF=0 and ZF=0).
    0F 87 cw JA rel16 D N.S. Valid Jump near if above (CF=0 and ZF=0). Not supported in 64-bit mode.
    0F 87 cw JNBE rel16 D N.S. Valid Jump near if not below or equal (CF=0 and ZF=0). Not supported in 64-bit mode.
    0F 88 cd JS rel32 D Valid Valid Jump near if sign (SF=1).
    0F 88 cw JS rel16 D N.S. Valid Jump near if sign (SF=1). Not supported in 64-bit mode.
    0F 89 cd JNS rel32 D Valid Valid Jump near if not sign (SF=0).
    0F 89 cw JNS rel16 D N.S. Valid Jump near if not sign (SF=0). Not supported in 64-bit mode.
    0F 8A cd JP rel32 D Valid Valid Jump near if parity (PF=1).
    0F 8A cd JPE rel32 D Valid Valid Jump near if parity even (PF=1).
    0F 8A cw JP rel16 D N.S. Valid Jump near if parity (PF=1). Not supported in 64-bit mode.
    0F 8A cw JPE rel16 D N.S. Valid Jump near if parity even (PF=1). Not supported in 64-bit mode.
    0F 8B cd JNP rel32 D Valid Valid Jump near if not parity (PF=0).
    0F 8B cd JPO rel32 D Valid Valid Jump near if parity odd (PF=0).
    0F 8B cw JNP rel16 D N.S. Valid Jump near if not parity (PF=0). Not supported in 64-bit mode.
    0F 8B cw JPO rel16 D N.S. Valid Jump near if parity odd (PF=0). Not supported in 64-bit mode.
    0F 8C cd JL rel32 D Valid Valid Jump near if less (SF≠ OF).
    0F 8C cd JNGE rel32 D Valid Valid Jump near if not greater or equal (SF≠ OF).
    0F 8C cw JL rel16 D N.S. Valid Jump near if less (SF≠ OF). Not supported in 64-bit mode.
    0F 8C cw JNGE rel16 D N.S. Valid Jump near if not greater or equal (SF≠ OF). Not supported in 64-bit mode.
    0F 8D cd JGE rel32 D Valid Valid Jump near if greater or equal (SF=OF).
    0F 8D cd JNL rel32 D Valid Valid Jump near if not less (SF=OF).
    0F 8D cw JGE rel16 D N.S. Valid Jump near if greater or equal (SF=OF). Not supported in 64-bit mode.
    0F 8D cw JNL rel16 D N.S. Valid Jump near if not less (SF=OF). Not supported in 64-bit mode.
    0F 8E cd JLE rel32 D Valid Valid Jump near if less or equal (ZF=1 or SF≠ OF).
    0F 8E cd JNG rel32 D Valid Valid Jump near if not greater (ZF=1 or SF≠ OF).
    0F 8E cw JLE rel16 D N.S. Valid Jump near if less or equal (ZF=1 or SF≠ OF). Not supported in 64-bit mode.
    0F 8E cw JNG rel16 D N.S. Valid Jump near if not greater (ZF=1 or SF≠ OF). Not supported in 64-bit mode.
    0F 8F cd JG rel32 D Valid Valid Jump near if greater (ZF=0 and SF=OF).
    0F 8F cd JNLE rel32 D Valid Valid Jump near if not less or equal (ZF=0 and SF=OF).
    0F 8F cw JG rel16 D N.S. Valid Jump near if greater (ZF=0 and SF=OF). Not supported in 64-bit mode.
    0F 8F cw JNLE rel16 D N.S. Valid Jump near if not less or equal (ZF=0 and SF=OF). Not supported in 64-bit mode.
    70 cb JO rel8 D Valid Valid Jump short if overflow (OF=1).
    71 cb JNO rel8 D Valid Valid Jump short if not overflow (OF=0).
    72 cb JB rel8 D Valid Valid Jump short if below (CF=1).
    72 cb JC rel8 D Valid Valid Jump short if carry (CF=1).
    72 cb JNAE rel8 D Valid Valid Jump short if not above or equal (CF=1).
    73 cb JAE rel8 D Valid Valid Jump short if above or equal (CF=0).
    73 cb JNB rel8 D Valid Valid Jump short if not below (CF=0).
    73 cb JNC rel8 D Valid Valid Jump short if not carry (CF=0).
    74 cb JE rel8 D Valid Valid Jump short if equal (ZF=1).
    74 cb JZ rel8 D Valid Valid Jump short if zero (ZF = 1).
    75 cb JNE rel8 D Valid Valid Jump short if not equal (ZF=0).
    75 cb JNZ rel8 D Valid Valid Jump short if not zero (ZF=0).
    76 cb JBE rel8 D Valid Valid Jump short if below or equal (CF=1 or ZF=1).
    76 cb JNA rel8 D Valid Valid Jump short if not above (CF=1 or ZF=1).
    77 cb JA rel8 D Valid Valid Jump short if above (CF=0 and ZF=0).
    77 cb JNBE rel8 D Valid Valid Jump short if not below or equal (CF=0 and ZF=0).
    78 cb JS rel8 D Valid Valid Jump short if sign (SF=1).
    79 cb JNS rel8 D Valid Valid Jump short if not sign (SF=0).
    7A cb JP rel8 D Valid Valid Jump short if parity (PF=1).
    7A cb JPE rel8 D Valid Valid Jump short if parity even (PF=1).
    7B cb JNP rel8 D Valid Valid Jump short if not parity (PF=0).
    7B cb JPO rel8 D Valid Valid Jump short if parity odd (PF=0).
    7C cb JL rel8 D Valid Valid Jump short if less (SF≠ OF).
    7C cb JNGE rel8 D Valid Valid Jump short if not greater or equal (SF≠ OF).
    7D cb JGE rel8 D Valid Valid Jump short if greater or equal (SF=OF).
    7D cb JNL rel8 D Valid Valid Jump short if not less (SF=OF).
    7E cb JLE rel8 D Valid Valid Jump short if less or equal (ZF=1 or SF≠ OF).
    7E cb JNG rel8 D Valid Valid Jump short if not greater (ZF=1 or SF≠ OF).
    7F cb JG rel8 D Valid Valid Jump short if greater (ZF=0 and SF=OF).
    7F cb JNLE rel8 D Valid Valid Jump short if not less or equal (ZF=0 and SF=OF).
    E3 cb JCXZ rel8 D N.E. Valid Jump short if CX register is 0.
    E3 cb JECXZ rel8 D Valid Valid Jump short if ECX register is 0.
    E3 cb JRCXZ rel8 D Valid N.E. Jump short if RCX register is 0.

    Original table from the above Jcc link:

    Opcode Instruction Op/En 64-Bit Mode Compat/Leg Mode Description
    77 cb JA rel8 D Valid Valid Jump short if above (CF=0 and ZF=0).
    73 cb JAE rel8 D Valid Valid Jump short if above or equal (CF=0).
    72 cb JB rel8 D Valid Valid Jump short if below (CF=1).
    76 cb JBE rel8 D Valid Valid Jump short if below or equal (CF=1 or ZF=1).
    72 cb JC rel8 D Valid Valid Jump short if carry (CF=1).
    E3 cb JCXZ rel8 D N.E. Valid Jump short if CX register is 0.
    E3 cb JECXZ rel8 D Valid Valid Jump short if ECX register is 0.
    E3 cb JRCXZ rel8 D Valid N.E. Jump short if RCX register is 0.
    74 cb JE rel8 D Valid Valid Jump short if equal (ZF=1).
    7F cb JG rel8 D Valid Valid Jump short if greater (ZF=0 and SF=OF).
    7D cb JGE rel8 D Valid Valid Jump short if greater or equal (SF=OF).
    7C cb JL rel8 D Valid Valid Jump short if less (SF≠ OF).
    7E cb JLE rel8 D Valid Valid Jump short if less or equal (ZF=1 or SF≠ OF).
    76 cb JNA rel8 D Valid Valid Jump short if not above (CF=1 or ZF=1).
    72 cb JNAE rel8 D Valid Valid Jump short if not above or equal (CF=1).
    73 cb JNB rel8 D Valid Valid Jump short if not below (CF=0).
    77 cb JNBE rel8 D Valid Valid Jump short if not below or equal (CF=0 and ZF=0).
    73 cb JNC rel8 D Valid Valid Jump short if not carry (CF=0).
    75 cb JNE rel8 D Valid Valid Jump short if not equal (ZF=0).
    7E cb JNG rel8 D Valid Valid Jump short if not greater (ZF=1 or SF≠ OF).
    7C cb JNGE rel8 D Valid Valid Jump short if not greater or equal (SF≠ OF).
    7D cb JNL rel8 D Valid Valid Jump short if not less (SF=OF).
    7F cb JNLE rel8 D Valid Valid Jump short if not less or equal (ZF=0 and SF=OF).
    71 cb JNO rel8 D Valid Valid Jump short if not overflow (OF=0).
    7B cb JNP rel8 D Valid Valid Jump short if not parity (PF=0).
    79 cb JNS rel8 D Valid Valid Jump short if not sign (SF=0).
    75 cb JNZ rel8 D Valid Valid Jump short if not zero (ZF=0).
    70 cb JO rel8 D Valid Valid Jump short if overflow (OF=1).
    7A cb JP rel8 D Valid Valid Jump short if parity (PF=1).
    7A cb JPE rel8 D Valid Valid Jump short if parity even (PF=1).
    7B cb JPO rel8 D Valid Valid Jump short if parity odd (PF=0).
    78 cb JS rel8 D Valid Valid Jump short if sign (SF=1).
    74 cb JZ rel8 D Valid Valid Jump short if zero (ZF = 1).
    0F 87 cw JA rel16 D N.S. Valid Jump near if above (CF=0 and ZF=0). Not supported in 64-bit mode.
    0F 87 cd JA rel32 D Valid Valid Jump near if above (CF=0 and ZF=0).
    0F 83 cw JAE rel16 D N.S. Valid Jump near if above or equal (CF=0). Not supported in 64-bit mode.
    0F 83 cd JAE rel32 D Valid Valid Jump near if above or equal (CF=0).
    0F 82 cw JB rel16 D N.S. Valid Jump near if below (CF=1). Not supported in 64-bit mode.
    0F 82 cd JB rel32 D Valid Valid Jump near if below (CF=1).
    0F 86 cw JBE rel16 D N.S. Valid Jump near if below or equal (CF=1 or ZF=1). Not supported in 64-bit mode.
    0F 86 cd JBE rel32 D Valid Valid Jump near if below or equal (CF=1 or ZF=1).
    0F 82 cw JC rel16 D N.S. Valid Jump near if carry (CF=1). Not supported in 64-bit mode.
    0F 82 cd JC rel32 D Valid Valid Jump near if carry (CF=1).
    0F 84 cw JE rel16 D N.S. Valid Jump near if equal (ZF=1). Not supported in 64-bit mode.
    0F 84 cd JE rel32 D Valid Valid Jump near if equal (ZF=1).
    0F 84 cw JZ rel16 D N.S. Valid Jump near if 0 (ZF=1). Not supported in 64-bit mode.
    0F 84 cd JZ rel32 D Valid Valid Jump near if 0 (ZF=1).
    0F 8F cw JG rel16 D N.S. Valid Jump near if greater (ZF=0 and SF=OF). Not supported in 64-bit mode.
    0F 8F cd JG rel32 D Valid Valid Jump near if greater (ZF=0 and SF=OF).
    0F 8D cw JGE rel16 D N.S. Valid Jump near if greater or equal (SF=OF). Not supported in 64-bit mode.
    0F 8D cd JGE rel32 D Valid Valid Jump near if greater or equal (SF=OF).
    0F 8C cw JL rel16 D N.S. Valid Jump near if less (SF≠ OF). Not supported in 64-bit mode.
    0F 8C cd JL rel32 D Valid Valid Jump near if less (SF≠ OF).
    0F 8E cw JLE rel16 D N.S. Valid Jump near if less or equal (ZF=1 or SF≠ OF). Not supported in 64-bit mode.
    0F 8E cd JLE rel32 D Valid Valid Jump near if less or equal (ZF=1 or SF≠ OF).
    0F 86 cw JNA rel16 D N.S. Valid Jump near if not above (CF=1 or ZF=1). Not supported in 64-bit mode.
    0F 86 cd JNA rel32 D Valid Valid Jump near if not above (CF=1 or ZF=1).
    0F 82 cw JNAE rel16 D N.S. Valid Jump near if not above or equal (CF=1). Not supported in 64-bit mode.
    0F 82 cd JNAE rel32 D Valid Valid Jump near if not above or equal (CF=1).
    0F 83 cw JNB rel16 D N.S. Valid Jump near if not below (CF=0). Not supported in 64-bit mode.
    0F 83 cd JNB rel32 D Valid Valid Jump near if not below (CF=0).
    0F 87 cw JNBE rel16 D N.S. Valid Jump near if not below or equal (CF=0 and ZF=0). Not supported in 64-bit mode.
    0F 87 cd JNBE rel32 D Valid Valid Jump near if not below or equal (CF=0 and ZF=0).
    0F 83 cw JNC rel16 D N.S. Valid Jump near if not carry (CF=0). Not supported in 64-bit mode.
    0F 83 cd JNC rel32 D Valid Valid Jump near if not carry (CF=0).
    0F 85 cw JNE rel16 D N.S. Valid Jump near if not equal (ZF=0). Not supported in 64-bit mode.
    0F 85 cd JNE rel32 D Valid Valid Jump near if not equal (ZF=0).
    0F 8E cw JNG rel16 D N.S. Valid Jump near if not greater (ZF=1 or SF≠ OF). Not supported in 64-bit mode.
    0F 8E cd JNG rel32 D Valid Valid Jump near if not greater (ZF=1 or SF≠ OF).
    0F 8C cw JNGE rel16 D N.S. Valid Jump near if not greater or equal (SF≠ OF). Not supported in 64-bit mode.
    0F 8C cd JNGE rel32 D Valid Valid Jump near if not greater or equal (SF≠ OF).
    0F 8D cw JNL rel16 D N.S. Valid Jump near if not less (SF=OF). Not supported in 64-bit mode.
    0F 8D cd JNL rel32 D Valid Valid Jump near if not less (SF=OF).
    0F 8F cw JNLE rel16 D N.S. Valid Jump near if not less or equal (ZF=0 and SF=OF). Not supported in 64-bit mode.
    0F 8F cd JNLE rel32 D Valid Valid Jump near if not less or equal (ZF=0 and SF=OF).
    0F 81 cw JNO rel16 D N.S. Valid Jump near if not overflow (OF=0). Not supported in 64-bit mode.
    0F 81 cd JNO rel32 D Valid Valid Jump near if not overflow (OF=0).
    0F 8B cw JNP rel16 D N.S. Valid Jump near if not parity (PF=0). Not supported in 64-bit mode.
    0F 8B cd JNP rel32 D Valid Valid Jump near if not parity (PF=0).
    0F 89 cw JNS rel16 D N.S. Valid Jump near if not sign (SF=0). Not supported in 64-bit mode.
    0F 89 cd JNS rel32 D Valid Valid Jump near if not sign (SF=0).
    0F 85 cw JNZ rel16 D N.S. Valid Jump near if not zero (ZF=0). Not supported in 64-bit mode.
    0F 85 cd JNZ rel32 D Valid Valid Jump near if not zero (ZF=0).
    0F 80 cw JO rel16 D N.S. Valid Jump near if overflow (OF=1). Not supported in 64-bit mode.
    0F 80 cd JO rel32 D Valid Valid Jump near if overflow (OF=1).
    0F 8A cw JP rel16 D N.S. Valid Jump near if parity (PF=1). Not supported in 64-bit mode.
    0F 8A cd JP rel32 D Valid Valid Jump near if parity (PF=1).
    0F 8A cw JPE rel16 D N.S. Valid Jump near if parity even (PF=1). Not supported in 64-bit mode.
    0F 8A cd JPE rel32 D Valid Valid Jump near if parity even (PF=1).
    0F 8B cw JPO rel16 D N.S. Valid Jump near if parity odd (PF=0). Not supported in 64-bit mode.
    0F 8B cd JPO rel32 D Valid Valid Jump near if parity odd (PF=0).
    0F 88 cw JS rel16 D N.S. Valid Jump near if sign (SF=1). Not supported in 64-bit mode.
    0F 88 cd JS rel32 D Valid Valid Jump near if sign (SF=1).
    0F 84 cw JZ rel16 D N.S. Valid Jump near if 0 (ZF=1). Not supported in 64-bit mode.
    0F 84 cd JZ rel32 D Valid Valid Jump near if 0 (ZF=1).

--jeroen

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GitHub – chip-red-pill/MicrocodeDecryptor

Posted by jpluimers on 2024/09/18

A few years back the way Intel Microcode updates were distributed deciphered so it became possible to extract and research the microcode of some processor models.

Repository: [Wayback/Archive] chip-red-pill/MicrocodeDecryptor

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Posted in Assembly Language, Development, Software Development, x64, x86 | Leave a Comment »

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