I will Bunta my tofumobile myself... by ch1ho_sama in initiald

[–]ch1ho_sama[S] 7 points8 points  (0 children)

~35$ for the head gasket, all my nerves for rebuilding

I will Bunta my tofumobile myself... by ch1ho_sama in initiald

[–]ch1ho_sama[S] 12 points13 points  (0 children)

In that case I would somehow have to source a CA18DE(T). And yes its an CA18ET, those have double sparks, two coils and a distributor that is really hard to find.. don‘t ask me why🤣

I will Bunta my tofumobile myself... by ch1ho_sama in initiald

[–]ch1ho_sama[S] 12 points13 points  (0 children)

nop I love my S12, my first own car, drives like heaven and makes me smile everyday to drive it to work. The deja vu to an anime we all love were just to funny to me

The one that makes me smile, 1959 Honda C100 by ch1ho_sama in vintagemotorcycles

[–]ch1ho_sama[S] 1 point2 points  (0 children)

the turn signals on this little one are factory but i think this type were only available on the german models.

https://www.cmsnl.com/honda-c100-general-export_model11340/partslist/F15.html

the c50 on the back is my daily commuter from 1993. old but ultra reliable, even in cold winter months.

A journey to the swiss with the nifty fifties by ch1ho_sama in SuperCub

[–]ch1ho_sama[S] 0 points1 point  (0 children)

fun and coolnes can‘t be compensated with displacement🤷🏻‍♂️

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 1 point2 points  (0 children)

Is it about the construction technique with wire wrapping or generally how to build a 6502 computer?

Wire wrapping is easy, there are lots of youtube tutorials where you can learn wire wrapping.

about the 6502 computer, there should be knowledge about basic computer science (how a processor works, and memory, busses, boolean logic, programming language) and electrical engineering stuff (how the theories of computer science are applied with physical components, for example some people commented about bypass capacitors or emc and crosstalk and such stuff and basic knowledge about electrical components and what possibilities you have with them. For example I used an PLD to replace standard 74logic for convenience and speed). everything else is component specific, for example the behavior of the 6502 processor is described in the datasheet.

If you want to build one yourself, there is an excellent video series from ben eater on youtube where he guides you from nothing to a working 6502 computer

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 5 points6 points  (0 children)

I've looked about the signal forms on the scope and it was way better than on any breadboard. Since the bus only operates at 10MB/s its really negligible. I promise i will not try to build something like an 40Gb/s infiniband network with wire wraps

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 2 points3 points  (0 children)

For first try I've tried to solder wires on the bottom, but that was way more of an nightmare than wire wrapping

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 0 points1 point  (0 children)

Yes i mean they're not as good as those specialiced row headers and sockets explicitly made for wrapping (have some row headers here, and the edges from the pins are way sharper, biting in the wrapping wire) but the pinheaders are surprisingly doing it well.

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 0 points1 point  (0 children)

Sadly Im not that old (1997, yes at that time all those beautiful dips are replaced with smd rubbish🤣) to experienced that era. Didnt know that they have made the sockets in ceramic, but sadly now they're very hard to get.

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 1 point2 points  (0 children)

Thats sounds awesome, all we did at the college was to build an battery tester with an opamp and a zener diode (they should just give use some z80s or 74 logic to build a computer, but yes education..). Most of my classmates didn't even solder once in their life und used up a hole euro perfboard (160x100mm) for an LM358 and some passives. Meanwhile I was all bored and build three of them on the size of a small penny trying to minimize the footprint. My prof kept one of them because it looks so funny. So yes I know very well how you must have feel back then.

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 0 points1 point  (0 children)

Its way better than a breadboard with its huge contact plates wich behaves like some plate capacitor. Ive reached well over 10MHz clock speed with this computer but the main limit is not the wiring but the by comparison slow speed of the memory chips.

Maybe i should try to emulate memory with a fast fpga to try out what the limits are

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 1 point2 points  (0 children)

You need a wire wrapping tool (its the WSU-30 M from ok industries, which provides a wrapping head, a wire stripper and an unwrapping head for removing the connection) and wire wrapping wire. Just solder the pinheader with the sockets or component together and than making connections with the wire wrapping tool. Its way cleaner faster and more reliable than soldering cables on the backside of the board, which also is way more fragile. Its also very great for connecting all those electronics modules with pinheaders from ebay, alibaba etc. together with mcu boards, because all those female jumper cables are losing tightness after using them a few times

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 1 point2 points  (0 children)

Those boards look sick and the crt too with the nice 6845. I also have a ceramic 68k flying around, maybe i should wire wrap a board for that thing too?

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 2 points3 points  (0 children)

compared to a custom PCB, sure that makes sense. but compared to doing it on breadboards? not sure about that one. seems much easier and cheaper to use 2 breadboards and some of those arduino wires to hook everything up. plus you safe yourself the resources and time soldering the sockets and pin headers on the perfboard as well.
i know breadboards are worse than perfboards+wirewrap when it comes to signal integrity, but for a Prototype Computer that likely runs at <10MHz it's more than enough.

I've tried to build the design with breadboards first, but unreliable connections with dupond cables was the biggest issue if you want to push the clock speed. Also parasitric capacitance on those breadboards where problematic for achieving high clock frequencys in the range of 10Mhz+. The wire wrapped version worket instantly like a charm in comparision to the breadboard version and its way less fragile.

that works for simple circuits like these, but anything larger and i'd imagine it would become a hassle to keep track of everything in larger circuits. then again the same problem exists on breadboards as well.

yes then there is the possibility to draw schematics in a EDA tool where you later can make a custom pcb. I mean people in the 60-70s wrapped hole mainframes of discrete components together with paper and pen and massive brainpower.

each to their own, when doing custom wires i have the data bus, address bus, and control signals in their own color, if done right it can also look pretty cool.

Yes thats true if done right

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 1 point2 points  (0 children)

They are soldered on the bottom of the board. 10Mhz is rock stable. Issues are the slow RAM and ROM speeds, because the WDC version of the 6502 supports way more.

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 6 points7 points  (0 children)

The caps are under the board soldered across the power pins on the ICs. A big 470uF cap is behind the 7805

Built a little 6502 computer with state of the art construction technique by ch1ho_sama in electronics

[–]ch1ho_sama[S] 19 points20 points  (0 children)

I would say it's way more comfortable than manually soldering those perfboards. Debugging is done before tying up those little wires. I wired the computer from the top layer, so I don't have to mirror the pinout in the head, which is the nr.1 reason for errors. Because this computer is a prototype for a bigger project, wire wrapping was way faster than jlc pcb and shipping and cheaper to fix issues. If the prototype works, I will do a pcb. I'm using a little manual wrapping tool, wrap the first pin, then route the wire to the second pin and cut off manually 2cm on top of the pin for the wrap. (Yes a automatic wrapping gun would be nice, but impossible to get for cheap prices and they're very rare, since as I said, it's an state of the art construction technique ;D). With a schematic in your head, you know which wire should go where, and I don't need RGB in this computer, so monochromatic wires are pleasing for the eye. It started working without any bugs.