MEGA65 FORUM

Prototype PCB!

append delete ordyne

Excellent to see this!

http://c65gs.blogspot.co.uk/2017/06/my-mega65-prototype-pcb-has-emerged.html

Does there need to be any more hardware testers for this/rev 2 ? :D

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append delete #1. PGSmobile

We can all only wish ;) There will be no more of this revision board, however. Its sole purpose is to help refine the design for the next revision.

append delete #2. Pcbindex

无论是在制造或组装过程中,还是在http://www.pcbindex.com/实际应用中,定制PCB必须具有可靠的性能至关重要。除了增加成本之外,组装过程中的缺陷可以随PCB一起带到终端产品上,这可能导致实际应用中出现故障,并导致出售时的索赔。因此,毫不夸张地说,从这方面来看,一块高质量PCB的成本可以忽略不计。

在细分市场,特别是在关键领域应用的制造产品市场,这种故障的影响是不可想象的。因此,在比较PCB价格时应牢记以上几点。尽管可靠,有保证和长寿命产品的初步成本很高,但从长远来看这确实是值得的。

append delete #3. Freddy Champagne

Whether it's in the manufacturing or assembly process, or in http://www.pcbindex.com/practical applications, custom PCBs must have reliable performance. In addition to increasing costs, defects in the assembly process can be brought along with the PCB to the end product, which can lead to failures in practical applications and lead to claims for sale. Therefore, it is no exaggeration to say that the cost of a high-quality PCB is negligible in this respect.

In the market segment, especially the manufacturing product market applied in key areas, the impact of such failure is unthinkable. Therefore, the above points should be kept in mind when comparing PCB prices. Although reliable, the initial cost of a guaranteed and long-lived product is high, it is indeed worth it in the long run.
_____________________________________________________________________

I just ran the chinese post trough translater, so people can quickly understand Pcbindex's posting.
;-)

append delete #4. LGB

I guess it was just a context sensitive spam, if a page has something to say about "PCB" and there is possibility to comment on that page, it will do automatically ;-P I see the very same msg in various forum/etc sites, without even being on-topic, just someone mentioned the word "PCB" in one post :)

append delete #5. Chris02

I'm disappointed that the board will not have sockets for SID chips. Seems kind of silly to make an add on cartridge.

Chris

append delete #6. PGSmobile

The reason is simply one of cost: to add enough area for the board will increase the cost of every board a lot, as the board is 6-layer. Much cheaper to make a simple 2-layer PCB for an add on cartridge.

Paul

append delete #7. Solei

I have probably mentioned it before - but why not make a simple dual layer daughtherboard to accommodate just the sid chips and filter caps, connected to the motherboard internally with a flat cable?

There is more than enough space inside the machine for it to fit - and this solution could also be supplied as a diy kit with standard through-hole components.

append delete #8. LGB

I'm not sure it would work, but since M65 will have cartridge port, and exactly that is suggested to be used for a "real" SID cartridge, it would be easy to provide an internal pin-header near the part of the PCB where the cartridge port is provided. So as @Solei suggested, it would be easy to provide an internal "cartridge" this way (ie, a daughter board) optionally (or even by default) fitted, without the need to design an very complex PCB to have these "add-ons" on the main PCB. Also, it wouldn't block the cartridge port from other devices, which can/could be the case if an external SID cartridge is plugged in, but some other cartridge wanted to be used as well ...

append delete #9. Chris02

Could you make the PCB board larger and cut down on some of the layers?

append delete #10. gardners

No, the problem is the FPGA has a zillion pins that all need to get out of the traffic jam that is the 300+ pin BGA connector.

append delete #11. gardners

Solei: What you are proposing is simply an internal cartridge, as LGB has also indicated. My understanding is that adding even the area for another internal connector is a problem, in part because there are lines going through all those layers all over the place, and pushing them all out the way of a large space for a connector would be non-trivial. If you were truly desperate to house the SIDs internally, it would probably be possible to do something horrible using the internal 34-pin floppy connector, as it has enough 5V lines.

append delete #12. LGB

Well, yes, a multiple layer board is nightmare even if you add an extra component somewhere because of its nature. I only suggested the internal pin header, as somehow the external cartridge connector must be connected to the PCB anyway, so it's maybe easier to provide an internal pin header very near to that point. All other places / solutions would require re-route the PCB design and maybe using more layers, as far as I can imagine the situation, though I have never seen the whole schematics of the M65 and/or board design at all ...

:: @LGB added on 05 May ’18 · 17:02

Also, adding an "internal cartridge pin header" would allow some personalization of adding always-used external hardware to the system, in the form of "external yeah, but well, internal to the case" :-P I would opt to try an SFX Sound Expander, home made, the OPL chip only, for example, as en extra.

append delete #13. Freddy Champagne

OPL Chip would be nice. And MIDI-Support. But in my opinion that belongs on a (Userport/Expantionport ?) Cartridge as an optional extention.
Simply because the amount of users who really want/need this are not as many as some might think.

append delete #14. LGB

@Freddy Champagne Yes, I said exactly this, an optional "internal cartridge expansion pin header". Surely, it's an optional internal "daugtherboard". But can be used for "real SID" PCB as well, since then probably a single layer/side little PCB is enough as well with a SID socket is enough, and it's extra cheap then rather than re-designing a 6/8 layer main PCB to have SID socket as well. And as a bonus it can be other PCBs as well like with that OPL, if someone wants, but not for everyone, as you also noticed.

append delete #15. Freddy Champagne

Btw.: does the MEGA65 have an buffered RTC onboard?
If not: would it be difficult to add the cassette-port on Board Rev. II or the MEGA 'AT' ;)
Because in my opinion, that port is not so useless as CBM tought. They used it only for tapes, but in real life there were many add-ons that used the cassette-port, especialy using i2c system, for RTC, and temperature-sensors, or similar.

append delete #16. PGSmobile

No RTC at the moment. I agree it would be a nice addition.

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