Search results

  1. How exactly are device drivers and interrupt handlers connected?

    Device occupies memory addresses and IO ports. It has a protocol for sending it commands, checking status, etc at those addresses. It supports hardware interrupts to achieve concurrency by allowing the CPU to move on and not babysit (eg polling in a loop). Host OS knows nothing about the...

  2. Does anyone have a comprehensive explanation of how the graphics system works?

    Call BIOS / VIDEO INT 10 to set mode 13h. Write bytes to A000:0000-FFFF in 256 color index mode and they appear on the screen. Address = y * 320 + x. Change palettes by setting pallette index to IO 3C8 and 3 successive writes to 3C9 with your RGB triplet. Simple as that. Should be some old...

  3. Three teenage burglars shot dead in Oklahoma. An AR-15 was used

    The projectile might go clean through, but the 12 inches of tissue around the bullet track will be turned into syrup and nearly every peripheral blood vessel from your toes and fingers to eyes and brain will over pressurize and rupture causing multiple organ failure. Center fire rifle...

  4. Is IT work a dead-end?

    Depends what you call IT. Plugging prefab parts into consumer PCs and turning them on or answering the phone is not IT. Too many people get away with putting words like "Cisco" or "VMware" on their resume and all they know for troubleshooting is what they learned in a class or "ping everything...

  5. Should one start learning programming from assembly?

    And these opinions are why today's fresh Java generation programmers know nothing about microprocessor and machine architecture and why it takes 8 GB RAM to play Tic Tac Toe in a web browser. Understanding assembly, even if not to program with it, but to understand fundamentals that haven't...

  6. How big is the processor's execution window for code optimization?

    The scope only goes so far as there are available execution units, rename registers, reservation stations, and pipeline stages. The entire point is simply to keep all resources doing something every clock. It's not about optimizing code, it's about the decode and schedule unit avoiding stalls...

  7. Data transfer between data segments

    You testing any of this yourself yet? You are getting in way too deep for someone who isn't even writing code and observing. An assembler would have told you instantly that mov mem, mem is invalid and you'd see it isn't in the opcode matrix.

  8. Data transfer between data segments

    mov mem, mem isn't valid at all period. It's a CPU not a DMAC. Mov with mem as an operand is either a load or store not both, thus only one operand can be mem not both. Excepting special complex CISC opcodes like rep and movs_ that take many many cycles and perform many separate operations and...

  9. Intel syntax assembly code using dereferenced pointers as offsets

    [ ] specifies a memory access. Without brackets you just do a register to register move. This type of syntax is merely to specify intended addressing mode so the assembler spits out the correct opcode. If you specify an explicit segment prefix or segment override it's obvious you want a memory...

  10. Calling a procedure that exists in another code segment

    I haven't looked at 64 bit implementations of Windows in depth.

  11. Python or powershell for automation?

    Sounds like this is primarily Windows and MS products you are working with so PowerShell is the way to go.

  12. Start with SQL or ACCESS?

    You can use Access with ODBC connectivity to use simple SQL queries but if you are serious I'd get a real RDBMS. MySQL, Postgres, SQL server , Oracle, etc. There are numerous advanced topics you won't be able to perform with Access. I don't know what all Access supports now days but I don't...

  13. Calling a procedure that exists in another code segment

    Extra credit: When you get into virtualization extensions for hardware virtualization to run hypervisors like ESXi, you basically have a privilege level -1 below 0 that lets you both multi task ring 0 processes and more importantly isolate them from knowing about each other.

  14. Calling a procedure that exists in another code segment

    Given that the portion of hardware we are taking about is the operating system's responsibility to program, and was put into the processor to facilitate OS protection, process isolation, and multitasking, you have to understand both at the same time. The answer is paging. Segmentation is no...

  15. Calling a procedure that exists in another code segment

    Saw this today on wiki, good recap on why you need a minimum of 2 segments per privilege level and why a typical OS with 2 privilege levels needs 4 identical segments to disable segmentation. In protected mode a segment can not be both writable and executable.[2][3] Therefore, when implementing...

  16. Using address and operand overrides in real address mode

    65816 didn't use prefixes. You could toggle accumulator and operand size and index register size both independently and back and forth at will anywhere. Standard beginning to end linear disassembly doesn't work because you have no idea how to parse it. You have to basically psuedo execute and...

  17. Using address and operand overrides in real address mode

    Idgaf. My house. My property. Time to close this thread as it's delving into dubious legal and swearing territory -- Programming Moderator Ken g6

  18. Share memory parallelisation with independent processes but shared output data in c++

    Dunno if relevant but double buffering your data state with public and private data makes for very fast parallel processing at the expense of memory (which is cheap and abundant). All objects dependent on other objects read the current state of other objects that is public facing and static for...

  19. Using address and operand overrides in real address mode

    When I did SNES I had a Double Pro Fighter copier unit, I could load my ROM onto floppy and loaded into RAM which sat in the cartridge address space and emulated cartridge access. Now we have flash cards like Super Everdrive, SD2SNES, and PowerPak that are far more convenient. Some even have...

  20. Calling a procedure that exists in another code segment

    It's not an x86 restriction. Popular mainstream OSes simply do not implement more than one user code segment for ring 3. Segmentation is abandoned for paging, it's only present on x86 legacy as mandatory even to set up a bare minimum to flat mode There are no other selectors to load in...

  21. Using address and operand overrides in real address mode

    I said if you made your own OS or used something unconventional like Multics that embraces segmentation vs paging. Its not a x86 restriction, just not implemented in Windows and Linux among other operating systems. Modern day popular mainstream operating systems have all abandoned segment...

  22. Is programming fun ?

    Programming metal > * No OS no BIOS, just you and the machine. There's nothing like it. SQL and HTML type stuff bores me to tears. But writing your own machine and instruction set in VHDL, synthesizing it, then writing software for it, and watching it spring to life...Yeah it's fun.

  23. Using address and operand overrides in real address mode

    If in real mode or a protected mode with CS pointing to a code segment descriptor with D bit set to 16 bit. In native 32 bit the prefix toggles the opposite. If you assemble 32 bit code eg a Windows application and you enter "mov ax, 9090" the assembler will spit out 66 B8 90 90 adding the...

  24. Translation from linear address space to physical address space when paging is turned off

    You can program the logic on the system board to establish the physical memory map (eg map the PCI to respond to 0xE0000000-EFFFFFFF) to map video RAM for example. 0xE0000000 for the CPU is 0x00000000 to the GPU the first byte of VRAM. This is controlling the programmable address decode and...

  25. Calling a procedure that exists in another code segment

    Because there is only one user mode execute segment descriptor and you don't have GDT access? The only time a far call, aka a CS code selector load, is used is to change privilege level on x86 and you are never doing that in an application in a protected multitasking OS. Your only 2...

  26. What do you mean I need more RAM?

    Yes you can lol. ESXi will just start thrashing 30+ .vswaps and your SAN will hate you.

  27. Translation from linear address space to physical address space when paging is turned off

    Assuming segment descriptor in long mode is base 0 limit 2^64-1 and no paging , and depending on the mother board, youd wrap, mirror, or the external logic would flag a bus error IRQ or something. Who knows :p Most likely it would just truncate the upper 16 bits and wrap and then it's up to...

  28. Using address and operand overrides in real address mode

    Real mode is fixed at 16 bit. You can actually enter into real mode 16 bit DOS debug and execute 32 bit code on 386+: E 200 0200 66 B8 90 90 90 90 CB U 200 0200 66 db 66 0201 B89000 mov ax, 9090 0204 90 nop 0205 90 nop 0206 CB ret RIP 200 The result if you trace this for ONE instruction...

  29. Calling a procedure that exists in another code segment

    That's not really done in modern times in user land. You'd only see those kinds of calls in DOS extenders with flat mode 32 bit programs with full exclusive access or in kernel code. Certainly not at user mode now days. Other than mov segment over rides to FS:[0] to get your thread info block...

  30. Does anyone have a strict definition for 'effective address'?

    Found this Section 3.7.5 (Specifying an Offset) of the same document states: The offset part of a memory address can be specified directly as a static value (called a displacement) or through an address computation made up of one or more of the following components: Displacement — An 8-...

  31. Does anyone have a strict definition for 'effective address'?

    Effective address has nothing to do with paging or segmentation. It simply means the actual final numerical address that is calculated from an instruction that uses variables or arithmetic in the address operand, eg indexing or scaling. If you are in protected mode with paging then the EA is...

  32. How do Intel systems know how much to increment the instruction pointer?

    Yup that's the one. I know dozens of CPUs and mix them up sometimes. 65816 and ARM 7 for example have explicit mode settings for 8/16 or 16/32 operation. X86 uses the D(efault) bit in the code segment active in CS to determine default operand mode. I did alot of 32 bit hacking in the DOS...

  33. Does anyone have a strict definition for 'effective address'?

    Effective address is the calculated linear address in the application memory map that is computed in a given instruction addressing mode. It has to do with what are called addressing modes. Absolute, absolute index, absolute index scaled with offset, and so on. Effective address is the address...

  34. How do Intel systems know how much to increment the instruction pointer?

    Part of the prefetcher and decoder hardware and predictor hardware. It's already parsing each operand size override and extended instruction prefix, opcode, and parameters as it encounters them so it already just knows. Simplified its like how you would write an emulator core: fetch next byte...

  35. 1Gbps is to slow

    Cat 5/5e is 100 MHz Any 300 MHz UTP is probably just Cat 6 but was probably called Cat 5e before 6 became a standard.

  36. 1Gbps is to slow

    If you saw how crazy 4D-PAM5 is just to squeeze gigabit out of cat 5... Problem is cat 5 is 125 MHz which was based on the 8/10b baseband for 100 Mbps. 10 gig is an entirely new modulation and requires 500 MHz cable to shoehorn it to use 4 pair UTP. It's really meant for twinax or single mode...

  37. Can segments overlap in protected mode?

    Sure. They overlap all the time. Modern x86 OSes have been overlapping at least 4 segments since forever. There is no limitation to prevent you from specifying same or overlapping base and limit in your segment descriptors. In fact you MUST overlap segments for modern page based x86 OSes...

  38. On to 2018

    Ditch the anti gun stance or you're doomed. As a libertarian/independent I will never support anyone who is anti gun. I don't care if it's only "some restrictions". If it's going to prevent me from purchasing a certain type of gun or make it impossible for me to be seen in public with a...

  39. It's over! 2016 Election Night Results Thread!

    Re Trump as the only option...hey Obama looks like we are eating our peas.

  40. It's over! 2016 Election Night Results Thread!

    I'm sure there will be short term costs. The difference is all other political issues can change on a whim with the party in power. And religion is dying, being gay or black or atheist is trending more and more socially accepted and will run its course naturally. Except guns. Guns are the one...
COMPANY
RESOURCES
FOLLOW
Top Bottom
sale-70-410-exam    | Exam-200-125-pdf    | we-sale-70-410-exam    | hot-sale-70-410-exam    | Latest-exam-700-603-Dumps    | Dumps-98-363-exams-date    | Certs-200-125-date    | Dumps-300-075-exams-date    | hot-sale-book-C8010-726-book    | Hot-Sale-200-310-Exam    | Exam-Description-200-310-dumps?    | hot-sale-book-200-125-book    | Latest-Updated-300-209-Exam    | Dumps-210-260-exams-date    | Download-200-125-Exam-PDF    | Exam-Description-300-101-dumps    | Certs-300-101-date    | Hot-Sale-300-075-Exam    | Latest-exam-200-125-Dumps    | Exam-Description-200-125-dumps    | Latest-Updated-300-075-Exam    | hot-sale-book-210-260-book    | Dumps-200-901-exams-date    | Certs-200-901-date    | Latest-exam-1Z0-062-Dumps    | Hot-Sale-1Z0-062-Exam    | Certs-CSSLP-date    | 100%-Pass-70-383-Exams    | Latest-JN0-360-real-exam-questions    | 100%-Pass-4A0-100-Real-Exam-Questions    | Dumps-300-135-exams-date    | Passed-200-105-Tech-Exams    | Latest-Updated-200-310-Exam    | Download-300-070-Exam-PDF    | Hot-Sale-JN0-360-Exam    | 100%-Pass-JN0-360-Exams    | 100%-Pass-JN0-360-Real-Exam-Questions    | Dumps-JN0-360-exams-date    | Exam-Description-1Z0-876-dumps    | Latest-exam-1Z0-876-Dumps    | Dumps-HPE0-Y53-exams-date    | 2017-Latest-HPE0-Y53-Exam    | 100%-Pass-HPE0-Y53-Real-Exam-Questions    | Pass-4A0-100-Exam    | Latest-4A0-100-Questions    | Dumps-98-365-exams-date    | 2017-Latest-98-365-Exam    | 100%-Pass-VCS-254-Exams    | 2017-Latest-VCS-273-Exam    | Dumps-200-355-exams-date    | 2017-Latest-300-320-Exam    | Pass-300-101-Exam    | 100%-Pass-300-115-Exams    |
http://www.portvapes.co.uk/    | http://www.portvapes.co.uk/    |