Groups | Search | Server Info | Login | Register
Groups > comp.os.linux.misc > #85278
| From | "Carlos E.R." <robin_listas@es.invalid> |
|---|---|
| Newsgroups | comp.os.linux.misc, alt.unix.geeks |
| Subject | Re: Mercury |
| Followup-To | alt.unix.geeks |
| Date | 2026-04-03 14:38 +0200 |
| Message-ID | <nuo4amxk3s.ln2@Telcontar.valinor> (permalink) |
| References | (7 earlier) <tr12amxjrq.ln2@Telcontar.valinor> <goqdne0QMPjDNVP0nZ2dnZfqnPednZ2d@giganews.com> <10qn15c$1hpad$1@dont-email.me> <U8ucnYMDksbRtlL0nZ2dnZfqn_adnZ2d@giganews.com> <10qnboc$1kfdg$1@dont-email.me> |
Cross-posted to 2 groups.
Followups directed to: alt.unix.geeks
{Note Followups-To} ==== means ====> do not post on comp.os.linux.misc
On 2026-04-03 05:21, Rich wrote:
> c186282 <c186282@nnada.net> wrote:
>> On 4/2/26 20:21, Rich wrote:
>>> c186282 <c186282@nnada.net> wrote:
>>>> On 4/2/26 07:51, Carlos E.R. wrote:
>>>>> On 2026-04-02 04:32, c186282 wrote:
>>>>>> On 4/1/26 21:33, Carlos E.R. wrote:
>>>>>>> On 2026-04-02 02:18, c186282 wrote:
>>>>>>>> On 2026-04-01 21:16, c186282 wrote:
>>>>>>>>
>>>>>>>> Not too long before he died he asked me to explain
>>>>>>>> exactly how a CPU worked - and I found I could not
>>>>>>>> provide a low-level description. Still can't, have
>>>>>>>> no idea how instruction-fetch/decode/data-routing
>>>>>>>> works at the bare transistor level.
>>>>>>>
>>>>>>> It is actually simple, but using gates, not transistors. Well,
>>>>>>> transistors is one step further, each group form a gate. And a group
>>>>>>> of gates form functions, like registers. It is overwhelming from
>>>>>>> scratch, but if someone explains a function at a time, it becomes
>>>>>>> "understandable". At least an old 8 bit CPU, like the 8085 or 6502. A
>>>>>>> modern one is more steps in complexity.
>>>>>>
>>>>>> I tried to study a 4004 ... but still couldn't
>>>>>> really assemble a mental model of how the needed
>>>>>> steps were done at the lowest level.
>>>>>>
>>>>>> 'Gates' are made from transistors. Those I get
>>>>>> just fine ... but how to build a CPU "machine"
>>>>>> out of them ............
>>>>>
>>>>> You need somebody explaining it. Or a book that explains it. Trying to
>>>>> study it doesn't work. It is complex, but there is a trick, a method of
>>>>> explaining it and suddenly the mind does "click!" and you understand it
>>>>> all.
>>>>
>>>> Could never get the 'click' alas. The sheer complexity of
>>>> how even a 'simple' CPU works is daunting. Oh well, too
>>>> old now, I'll never get it. Can form an abstract picture,
>>>> but the silicon details ... nope .....
>>>
>>> If you've no experience in the area, then trying to study a 4004 to
>>> determine how a CPU works is still *way* too far up the complexity
>>> curve to be able to easily grasp (absent a Herculean amount of effort).
>>>
>>> Do you "get" how an assembly line (i.e., auto assembly line) works?
>>>
>>> A loose (very loose) analagy is a CPU works somewhat like an auto
>>> assembly line. Everything moves along a step at a time on the line in
>>> unison to a clock pulse, and each stopping point on the "line" does
>>> some small bit towards completion of the action called for by the
>>> instruction. For this analogy the 'instructions' would be the cars
>>> moving down the line.
>>
>> I get it in the abstract ... but how to get transistors
>> to do it all click-click-click - sorry. The complexity
>> becomes daunting VERY fast.
>
> If you have no experience in the area, agreed.
>
> But if you do, the leap from transistors to simple clocked circuits
> (and a CPU is simply a large clocked circuit) is not really that hard.
>
> But, to get the leap between the two, you first have to understand how
> transistors can make logic gates (individual AND, OR, XOR gates) and
> then how those logic gates can themselves (if viewed as the "atomic
> element" in the system) be used to create flip-flops. Once you get
> that much, then the flip-flop is extended a bit into a gated (or
> clocked) flip-flop. Once you get there, then a CPU is really just (in
> one manner of viewing it) a huge number of gated flip-flops all
> marching to the same clock signal. The clocked flip-flop design is the
> secret behind how all the transistors do it click-clack-click.
>
> This wikipedia page shows (in the first portions) some transistor level
> flip-flop designs.
>
> https://en.wikipedia.org/wiki/Flip-flop_(electronics)
>
> and then transitions into logic gates as the smallest element of the
> internals of a flip-flop (consider each logic gate as being the same
> "transistor design" inside, i.e., all or gates being the same internal
> transistor design [which is not far from the truth with modern design
> software]). Then it adds gating to the basic flip-flops, and it is the
> gating that allows the "everything moves in reference to the clock
> signal" part.
>
>> In reference, my old uncle wanted to know how it was done at the
>> transistor (or 'valve') level. If he was a bit younger he'd
>> probably have tried to make a CPU out of vacuum tubes :-)
>
> He'd have had a *lot* of vacuum tubes, and the power draw and heat
> dissipation would have been huge, but for a really simple CPU, it can
> be done.
>
> Part of being able to understand it is being able to compartmentalize
> the aspects. When looking at a bunch of clock synchronous gated
> flip-flops you don't bother thinking about the internal logic gates
> that make them up, you just have "gated flip-flops" as your smallest
> "lego" piece. In the rare instance you need to worry about what's
> going on inside one flip-flop, you look at its insides as logic gates
> and don't think about the transistors that are inside. The layering of
> abstractions helps keep the overall complexity managable.
Right.
>
> But, it isn't something easy to convey in a short explanation to one's
> elderly uncle.
Nope, that can't be done. A gate, probably.
--
Cheers, Carlos.
ES🇪🇸, EU🇪🇺;
Back to comp.os.linux.misc | Previous | Next — Previous in thread | Next in thread | Find similar
Re: Mercury rbowman <bowman@montana.com> - 2026-03-31 02:30 +0000
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-03-31 12:58 +0200
Re: Mercury rbowman <bowman@montana.com> - 2026-03-31 20:10 +0000
Re: Mercury Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-03-31 22:03 +0000
Re: Mercury rbowman <bowman@montana.com> - 2026-04-01 04:37 +0000
Re: Mercury The Natural Philosopher <tnp@invalid.invalid> - 2026-04-01 13:26 +0100
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-01 09:03 -0400
Re: Mercury Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-04-01 17:58 +0000
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-01 15:16 -0400
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-01 21:57 +0200
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-01 20:18 -0400
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-02 03:33 +0200
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-01 22:32 -0400
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-02 13:51 +0200
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-02 13:33 -0400
Re: Mercury Rich <rich@example.invalid> - 2026-04-03 00:21 +0000
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-02 22:51 -0400
Re: Mercury Rich <rich@example.invalid> - 2026-04-03 03:21 +0000
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-03 14:38 +0200
Re: Mercury rbowman <bowman@montana.com> - 2026-04-03 06:22 +0000
Re: Mercury Bobbie Sellers <bliss-sf4ever@dslextreme.com> - 2026-04-03 07:50 -0700
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-03 11:13 -0400
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-03 14:33 +0200
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-03 11:06 -0400
Re: Mercury Rich <rich@example.invalid> - 2026-04-03 16:51 +0000
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-03 14:47 -0400
CPU architecture (was Re: Mercury) John Ames <commodorejohn@gmail.com> - 2026-04-03 12:57 -0700
Re: CPU architecture (was Re: Mercury) c186282 <c186282@nnada.net> - 2026-04-03 22:45 -0400
Re: CPU architecture (was Re: Mercury) Rich <rich@example.invalid> - 2026-04-04 03:27 +0000
Re: CPU architecture (was Re: Mercury) rbowman <bowman@montana.com> - 2026-04-04 04:57 +0000
CPU design "Carlos E.R." <robin_listas@es.invalid> - 2026-04-03 22:00 +0200
Re: CPU design c186282 <c186282@nnada.net> - 2026-04-03 16:29 -0400
Re: CPU design "Carlos E.R." <robin_listas@es.invalid> - 2026-04-04 13:20 +0200
Re: CPU design c186282 <c186282@nnada.net> - 2026-04-04 13:57 -0400
Re: CPU design "Carlos E.R." <robin_listas@es.invalid> - 2026-04-04 22:18 +0200
Re: CPU design Rich <rich@example.invalid> - 2026-04-05 03:44 +0000
Re: CPU design "Carlos E.R." <robin_listas@es.invalid> - 2026-04-05 13:58 +0200
Re: CPU design c186282 <c186282@nnada.net> - 2026-04-05 17:19 -0400
Re: CPU design The Natural Philosopher <tnp@invalid.invalid> - 2026-04-05 12:42 +0100
Re: Mercury Rich <rich@example.invalid> - 2026-04-03 21:57 +0000
Re: Mercury rbowman <bowman@montana.com> - 2026-04-03 17:54 +0000
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-03 22:29 -0400
Re: Mercury rbowman <bowman@montana.com> - 2026-04-04 04:58 +0000
Re: Mercury The Natural Philosopher <tnp@invalid.invalid> - 2026-04-04 13:30 +0100
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-04 13:46 -0400
Re: Mercury rbowman <bowman@montana.com> - 2026-04-04 19:22 +0000
Re: Mercury Robert Riches <spamtrap42@jacob21819.net> - 2026-04-04 20:39 +0000
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-04 18:10 -0400
Re: Mercury rbowman <bowman@montana.com> - 2026-04-05 03:31 +0000
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-05 17:13 -0400
Re: Mercury Rich <rich@example.invalid> - 2026-04-05 03:59 +0000
Re: Mercury rbowman <bowman@montana.com> - 2026-04-04 19:09 +0000
Re: Mercury Rich <rich@example.invalid> - 2026-04-04 14:26 +0000
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-04 13:50 -0400
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-03 21:55 +0200
Re: Mercury The Natural Philosopher <tnp@invalid.invalid> - 2026-04-04 13:40 +0100
Re: Mercury Rich <rich@example.invalid> - 2026-04-04 14:32 +0000
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-04 18:44 +0200
Re: Mercury rbowman <bowman@montana.com> - 2026-04-04 19:02 +0000
Re: Mercury The Natural Philosopher <tnp@invalid.invalid> - 2026-04-05 12:17 +0100
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-05 13:59 +0200
Re: Mercury The Natural Philosopher <tnp@invalid.invalid> - 2026-04-05 13:10 +0100
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-05 19:50 +0200
Re: Mercury rbowman <bowman@montana.com> - 2026-04-05 22:02 +0000
Re: Mercury Bobbie Sellers <bliss-sf4ever@dslextreme.com> - 2026-04-05 17:01 -0700
Re: Mercury rbowman <bowman@montana.com> - 2026-04-06 02:05 +0000
Mandriva was Re: Mercury Bobbie Sellers <bliss-sf4ever@dslextreme.com> - 2026-04-05 21:18 -0700
Re: Mandriva was Re: Mercury rbowman <bowman@montana.com> - 2026-04-06 16:02 +0000
Re: Mandriva was Re: Mercury Rich <rich@example.invalid> - 2026-04-06 18:09 +0000
Re: Mandriva was Re: Mercury rbowman <bowman@montana.com> - 2026-04-07 02:15 +0000
Re: Mandriva was Re: Mercury Bobbie Sellers <bliss-sf4ever@dslextreme.com> - 2026-04-06 14:53 -0700
Re: Mercury The Natural Philosopher <tnp@invalid.invalid> - 2026-04-06 11:01 +0100
CPU architecture (was Re: Mercury) John Ames <commodorejohn@gmail.com> - 2026-04-02 10:43 -0700
Re: CPU architecture (was Re: Mercury) The Natural Philosopher <tnp@invalid.invalid> - 2026-04-02 19:44 +0100
Re: CPU architecture (was Re: Mercury) c186282 <c186282@nnada.net> - 2026-04-02 15:06 -0400
Re: CPU architecture (was Re: Mercury) The Natural Philosopher <tnp@invalid.invalid> - 2026-04-03 10:32 +0100
Re: CPU architecture (was Re: Mercury) rbowman <bowman@montana.com> - 2026-04-03 23:58 +0000
Re: CPU architecture (was Re: Mercury) "Carlos E.R." <robin_listas@es.invalid> - 2026-04-03 15:11 +0200
Re: CPU architecture (was Re: Mercury) c186282 <c186282@nnada.net> - 2026-04-02 14:56 -0400
Re: CPU architecture (was Re: Mercury) John Ames <commodorejohn@gmail.com> - 2026-04-02 15:31 -0700
Re: CPU architecture (was Re: Mercury) c186282 <c186282@nnada.net> - 2026-04-02 22:46 -0400
Re: CPU architecture (was Re: Mercury) rbowman <bowman@montana.com> - 2026-04-03 07:03 +0000
Re: CPU architecture (was Re: Mercury) The Natural Philosopher <tnp@invalid.invalid> - 2026-04-03 11:25 +0100
The New Feudalism Lars Poulsen <lars@beagle-ears.com> - 2026-04-03 06:33 -0700
Re: CPU architecture (was Re: Mercury) John Ames <commodorejohn@gmail.com> - 2026-04-03 10:47 -0700
Re: CPU architecture (was Re: Mercury) Richard Kettlewell <invalid@invalid.invalid> - 2026-04-03 10:04 +0100
Re: CPU architecture (was Re: Mercury) The Natural Philosopher <tnp@invalid.invalid> - 2026-04-03 12:29 +0100
Re: CPU architecture (was Re: Mercury) c186282 <c186282@nnada.net> - 2026-04-03 10:35 -0400
Re: CPU architecture (was Re: Mercury) rbowman <bowman@montana.com> - 2026-04-03 07:00 +0000
Re: CPU architecture (was Re: Mercury) The Natural Philosopher <tnp@invalid.invalid> - 2026-04-03 11:27 +0100
Re: CPU architecture (was Re: Mercury) John Ames <commodorejohn@gmail.com> - 2026-04-03 13:54 -0700
Re: CPU architecture (was Re: Mercury) "Carlos E.R." <robin_listas@es.invalid> - 2026-04-03 22:54 +0200
Re: CPU architecture (was Re: Mercury) Rich <rich@example.invalid> - 2026-04-03 03:45 +0000
Re: CPU architecture (was Re: Mercury) Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-04-03 18:10 +0000
Re: CPU architecture (was Re: Mercury) c186282 <c186282@nnada.net> - 2026-04-03 15:04 -0400
Re: CPU architecture (was Re: Mercury) The Natural Philosopher <tnp@invalid.invalid> - 2026-04-03 10:13 +0100
Re: CPU architecture (was Re: Mercury) Rich <rich@example.invalid> - 2026-04-03 00:29 +0000
Re: Mercury rbowman <bowman@montana.com> - 2026-04-02 19:50 +0000
Re: Mercury Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-04-02 20:53 +0000
Re: Mercury The Natural Philosopher <tnp@invalid.invalid> - 2026-04-03 10:51 +0100
Re: Mercury The Natural Philosopher <tnp@invalid.invalid> - 2026-04-02 11:15 +0100
Re: Mercury rbowman <bowman@montana.com> - 2026-04-02 00:12 +0000
Re: Mercury rbowman <bowman@montana.com> - 2026-04-02 00:28 +0000
Re: Mercury c186282 <c186282@nnada.net> - 2026-04-01 21:39 -0400
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-02 14:17 +0200
Re: Mercury "Carlos E.R." <robin_listas@es.invalid> - 2026-04-01 14:47 +0200
csiph-web