Super turbo PCB layout

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Por msxmakers

Champion (502)

Imagen del msxmakers

27-01-2023, 12:30

it's working, even I needed to glue the pins for switch and led on the surface.
if someone would like to take the lowfreq from motherboard can do it at that pin of X1.

Por SkalTura

Champion (395)

Imagen del SkalTura

29-01-2023, 11:57

Okay, so you want the following changes:
1) If I understand it correctly, you don't want the X1 oscillator, but want to use the clock from the MSX itself. Then the clock from MSX goes into the circuit, and the clock output of the circuit goes to the Z80 CPU.
2) A header to connect an LED, and a header for a switch.

Please see below circuit if this is what you mean:

NOTE: The capacitor C6 in your photo is not correct, needs to be an tantalum capacitor or electrolytic capacitor

Por SkalTura

Champion (395)

Imagen del SkalTura

29-01-2023, 13:18

So for now I modified it to look like this:

A header connector for the LED, with ground.
And a header for 2 inputs, also with ground.
On the bottom you can see the square indicating the ground pins.
The IORQ pin is still connected to one of the diode pins, just like in the schematic. But can easily be removed if you don't need it...

And the X1 oscillator is removed with the components needed for the oscillator.
And instead it takes the clock from the DIP40 PIN6 socket.

Is that basically what you meant ?

Por msxmakers

Champion (502)

Imagen del msxmakers

29-01-2023, 19:03

SkalTura wrote:

1) If I understand it correctly, you don't want the X1 oscillator, but want to use the clock from the MSX itself. Then the clock from MSX goes into the circuit, and the clock output of the circuit goes to the Z80 CPU.
2) A header to connect an LED, and a header for a switch.

Please see below circuit if this is what you mean:

NOTE: The capacitor C6 in your photo is not correct, needs to be an tantalum capacitor or electrolytic capacitor

hello,
pin 6 from socket can be directly connected to IC3 pin 6 (sorry I didn't tell you but I saw it now). That way pins 10 and 11 on 74HC04 should be disconnected (or better with pin 11 connected to vcc, I think this avoid interferences).
All the rest you mean is correct.
About the capacitor, ... is a ceramic bi-polar capacior for the same value. Why is worst? the prototype is working.

Por msxmakers

Champion (502)

Imagen del msxmakers

29-01-2023, 19:52

SkalTura wrote:

A header connector for the LED, with ground.
And a header for 2 inputs, also with ground.
On the bottom you can see the square indicating the ground pins.
The IORQ pin is still connected to one of the diode pins, just like in the schematic. But can easily be removed if you don't need it...
And the X1 oscillator is removed with the components needed for the oscillator.
And instead it takes the clock from the DIP40 PIN6 socket.
Is that basically what you meant ?

Yes, many thanks.
I can't see clearly what you did with the 5 pin holes but, only one diode joined to IOREQ pin and it would be nice to have a second diode connected to a pin, but it looks like you used 2 SOT23 diode parts (four diodes in fact) I am wrong?
About the 47R resistor I think is not needed.
Anyone here knows what is the purpose for this resistor? I think it was needed only if the output frequency returns to the motherboard were another frequency could be on that wire.

Por SkalTura

Champion (395)

Imagen del SkalTura

30-01-2023, 07:22

msxmakers wrote:

I can't see clearly what you did with the 5 pin holes but, only one diode joined to IOREQ pin and it would be nice to have a second diode connected to a pin, but it looks like you used 2 SOT23 diode parts (four diodes in fact) I am wrong?
About the 47R resistor I think is not needed.
Anyone here knows what is the purpose for this resistor? I think it was needed only if the output frequency returns to the motherboard were another frequency could be on that wire.

I did use 2 SOT23 diodes, but if you only need 1, then I will remove the other one. It will save some space as well.
Don't think it will matter if the resistor is in the output or not. Otherwise you can just replace it with a 0 ohm one, or a dot of solder.

Por msxmakers

Champion (502)

Imagen del msxmakers

30-01-2023, 19:08

SkalTura wrote:
msxmakers wrote:

I can't see clearly what you did with the 5 pin holes but, only one diode joined to IOREQ pin and it would be nice to have a second diode connected to a pin, but it looks like you used 2 SOT23 diode parts (four diodes in fact) I am wrong?
About the 47R resistor I think is not needed.
Anyone here knows what is the purpose for this resistor? I think it was needed only if the output frequency returns to the motherboard were another frequency could be on that wire.

I did use 2 SOT23 diodes, but if you only need 1, then I will remove the other one. It will save some space as well.
Don't think it will matter if the resistor is in the output or not. Otherwise you can just replace it with a 0 ohm one, or a dot of solder.

ok, it could be good with two SOT diode pairs and 47 ohm resistor. it was just for saving board space.
thankyou

Por SkalTura

Champion (395)

Imagen del SkalTura

31-01-2023, 08:13

msxmakers wrote:

ok, it could be good with two SOT diode pairs and 47 ohm resistor. it was just for saving board space.
thankyou

No worries, I already had a lack of space with the original design, but made it work anyway Wink
I will try to have the final result finished coming weekend...

Por SkalTura

Champion (395)

Imagen del SkalTura

02-02-2023, 08:25

Had some spare time...

So this should be the final result I think.
Clock pin from the DIP40 goes directly into IC3, clock output goes of the circuit goes to the Z80 QFP.
Only 1 SOT diode, one pin connected to the IORQ pin, and the other pin connected to the SW header.
And then a header for the LED output. Marked on the bottom of the PCB is where the + (anode) of the LED goes.

And I also added the Via test points you requested by email, and marked them on the top of the PCB with a little circle around them.


Let me know if this is what you want, then I will generate the Gerber files for you...

Por msxmakers

Champion (502)

Imagen del msxmakers

02-02-2023, 20:01

SkalTura wrote:

Had some spare time...

Thank you so much.
It looks actually nice.
Now I understood why you left two SOT23 diode parts: the switch also needs diode.
ok, sorry for that but if you still have pcb space it would be better to have 4 diodes, I don't need more but some traditional MSX must need those diodes, at least one more spare.
I have tested this circuit on my OMEGA MSX until 20Mhz and worked woderful, how wonder if some other msx would get that but I think we could be happy if they can run at 8Mhz without modifying their Motherboards.
Let me know when you have the gerbers.
Thank you in advance
Hannibal

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