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69

The Alpha team set out to create a high-performance architecture, planned to last for 25 years and allow for 1000-performance increase over those 25 years. So they placed some long bets, starting with the 64-bit design (which cost performance but ensured long-term viability). It wasn’t designed to compete with x86 (which wasn’t perceived as a viable long-...


47

Stephen Kitt has done what seems to me an excellent job of outlining features and when they were introduced. I'll take a slightly different tack, instead picking a single point in time, and pointing out differences between the two at that time. I'm going to choose the 21164 as the Alpha to compare. It came out in January of 1995. It had a 266 MHz clock ...


45

Clock to clock Tualatin Pentium 3 was a lot faster (i.e. a P3 got more done in each clock cycle than a P4). High-end Pentium 3 is available at 1.4 GHz while low-end Pentium 4 is 1.5 GHz so if you compare these extremes P3 is the clear winner. But as time went on, Northwood Pentium 4 1.8 GHz plus DDR 266 memory became common quickly while Intel constrained ...


32

The extra pins were forward-planning, on both Socket 2 and Socket 3. Most of the extra pins are used for power (Vcc) and ground (Vss), which is useful to provide more power to a CPU. The other pins are keys, a new INIT pin (F19), and signals used for enabling and controlling the write-back L1 cache. (See the socket 3 specifications in the 486 family ...


26

I’m assuming you’re asking about x86 processors, not the older 8-bit CPUs. Real mode is always segmented, and everything (CPU, operating system, programs, even peripherals on the CPU bus) has access to all the system’s address space up to just over 1 MiB (1 MiB strictly before the 286). You can write programs without paying attention to segments, and you’ll ...


24

The very earliest, slowest-clocked, Pentium 4 chips were slower than the fastest Pentium IIIs of the time. The PIII was available at 1GHz when the Pentium 4 was introduced, and a 1.5GHz P4 was about the same practical speed: it varied a bit, according to what you were running. However, the P4 was also available in 1.3GHz and 1.4GHz clock-speeds, and those ...


19

I found this page on the motherboard, which says they are some sort of "32-bit external memory card." What are these slots? They are exactly that, memory expansion. This is a rather early 386 board from before memory modules became a thing. The mainboard can be fitted with 1 MiB using 256 KiBit chips (41256), so any expansion has to go on cards. With (AT)...


15

The answer is sort of. Intel also went with a different memory subsystem, RDRAM, which had a big influence on system performance. I'll be basing my answer on the AnandTech review of the Pentium III vs Pentium 4 vs AMD Thunderbird. Let's start out by looking at performance in a popular game of the time, Quake III Arena. You can see the Pentium 4 is the ...


13

It started out as a single manual covering hard and software, the The 8086 Family User's Manual. Before that there were only data sheets and manuals about single components, software tools and development boards as well as premade components (iSBC computer boards) (*1). After that it became the iAPX 86,88 User's Manual. The 80286 manuals (*2) were the ...


12

Why it has been designed, where it has been used? Its target market was terminals. The 8275 is a very versatile logic chip for generating text displays (*1) so nearly any terminal format of that time, with up to 80 characters and whatever attributes needed, can be handled. It was made to cover the full range from simple 32x20 with 8x8 cells all the way to ...


11

Short Answer: Yes. Celeron is a sales name, and does not specify a CPU architecture or instruction set. Having said that, FCOMIP was introduced with the P6 Family, so essentially with the Pentium PRO (for workstation) and Pentium MMX for mainstream machines. IA-32 implementations before these CPUs do not feature this instruction. The first Celeron is ...


10

Alpha fizzled in the face of the HP/Intel partnership pushing their Itanium 64-bit architecture I think it's important to note that during this period, there was a widespread belief that the VLIW approach was "the next RISC". Existing RISC approaches were growing into the millions of transistors and the outright performance gap that existed in the 1990s ...


8

Socket 3 did not have more pins than needed. It was designed to support the Pentium OverDrive CPUs that Intel released in the mid-1990s. These CPUs could have up to 237 pins, while the Socket 3 allowed 238 pins.


7

Is it true that the Pentium III was faster than its successor Pentium IV? Yes and no. As usual it all depends on the time to look at, but also what is defined as 'fast'. MHz vs. Throughput vs. Bang per Buck. In the MHz game (*1) the Netburst (Pentium 4) design clearly outran the P6 (Pentium II/III; *2). In throughput it was much like with every new design....


6

To add to Raffzahn's answer: I strengthen the "might not be compatible to 16-bit cards" to "are most likely not compatible to 16-bit cards". As I see the traces on the photo, there is nothing that supports the impression these slots are ISA 16-bit compatible - but also no proof they are not. A reliable tool to learn more about that board is a continuity ...


6

The August 10, 1987 issue of InfoWorld lists a number of boards which were announced at that year’s SIGGRAPH: Univision Technologies’ UDC-803 Bell Technologies’ Blit Express Vermont Microsystems’ Page Manager 100 The first two were workstation-style cards, supporting respectively 1600×1280 and 1664×1200, designed to work on the ISA bus; the latter was more ...


6

Intel 8008 CPU has an internal stack, implemented as an 8 x 16-bit scratchpad. No, it's entries are 'only' 14 bit long, as all addressing on the 8008 supports only 14 bit (*1). How does it work exactly? Is there any "invisible 3-bit stack pointer"? Yes. In reality it's not a stack pointer, but selects the active PC. A three-bit address pointer ...


5

Yes, there were other co-processors for the IBM PC computer other then Intel 8087 NPU/FPU Units. Many of them had additional circuity with some RAM and a ROM chips. The ROM chips on some of them contained an FPU emulation program if it was using a standard microprocessor other than a Intel model. Others had a BIOS extension for the system. Some older issues ...


5

Yes it is possible to have an IDE controller on a 8087 NPU (FPU) coprocessor socket. Most of these adapters had a circuit to switch in a BIOS and RAM cache Overlay when the IDE controller logic required it. .. Another example of this would be any expansion card that used the Dec. Rainbow 100 computers memory expansion card slot for peripherals. The card ...


5

1) All software sees the full 20bit address space, since there is no distinction between kernel and user land. 2) Flat mode is simply all segment descriptors set to maximum length and base offset 0. This is not feasible in 16 bit protected mode (80286), but most 80386 operating systems will use this mode in protected mode. There are other alternatives ...


5

Older slot 1 boards only support 66MHz front-side buses and won’t boot with a Coppermine core. Coppermines use a 100MHz or 133MHz FSB. Any motherboard officially supporting the latter should also support Coppermine. Motherboards only supporting 100MHz FSB may work with 100MHz FSB Coppermines, or even 133MHz if overclocked, but it’s not guaranteed — for ...


5

In Appendix C (on software compatibility to the 8086), the Intel 286 users manual states the following about instruction length (Page C-2): Do not Duplicate Prefixes. The 80286 sets an instruction length limit of 10 bytes. The only way to violate this limit is by duplicating a prefix two or more times before an instruction. Exception 6 occurs if the ...


4

Raffzahn’s answer lists the early manuals in the history of x86 documentation. To answer more specifically concerning version 71 of the Intel ® 64 and IA-32 Architectures Software Developer’s Manual, see order number 252046, Documentation Changes: version 1 of the manual was released in 2002, to document the first 64-bit x86 Intel CPUs. It replaced the IA-...


4

I was at HP when the Alpha cancellation decision was made. In fact I was part of a team that ran comparative HPC benchmarks on Alpha and x86. The fact was that by 1999 the x86 Pentium-II was matching the Alpha in floating point performance. This was reported by objective groups, e.g. Dongarra et al. Unfortunately the Alpha ecosystem was 10x more ...


4

The HMOS 8086 (as opposed to the CMOS 80C86) has a specified maxmial clock period of 500ns which translates to 2MHz in its datasheet on page 15 . It will fail to work if it is clocked significantly slower. So manual clocking is not possible on that chip. But what you can do is to generate an arbitrary amount of wait states. My recommendation would be to set ...


4

its common to have minimal circuit in the CPU (complete) datasheet This is first I found: i8086 datasheet Here image taken from page 59: Looks like this page handles it in more depth: min/max mode 8086 system


4

The original Pentium, which succeeded the i80486, was indeed the original definition of the i586 instruction set - and not x86_64. But the Pentium was introduced in 1993, and your HP machine is much newer than that. Intel has continued to use the Pentium brand for almost every x86-compatible CPU line they've made since then, to great confusion among people ...


3

http://www.idhw.com/textual/guide/inst_mobo_ami.html offers the following breakdown of the BIOS ID: D: BIOS w/ diagnostics PAQ: Compaq compatible 386 boards 6156: this Manufacturer code is not listed, but Genoa is 6165 and American Predator Corp. is 6155, so possibly an alternative code for one of those. Wim's BIOS lists 6156 as Genoa. 043090: MMDDYY BIOS ...


3

I'm editing my answer (again). Originally I thought this board might be a variation of: BEC COMPUTER ENTERPRISE 80486AT (Ver. 1.0) Everything except the position of the BIOS and the TAG seemed to match, but that could have been errors in the diagram. However, I am now thinking this is a better match: KOUWELL ELECTRONIC CORPORATION 486-33EZ As near as I ...


3

Datasheet for the Intel 8008 CPU mentions that the Carry (C) flag is affected with the logic operations (AND, OR, XOR), but it does not make any sense. I believe Carry will be zeroed, but I have no proof of this conclusion. First, the manual does not say anything special about logic operations but states: The result of the ALU instructions affect all of the ...


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