My 610 board build.

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HOWARDHB
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Re: My 610 board build.

Post by HOWARDHB »

...strange indeed!

I note that U6 & 7 are not N8T28 , however, MC6889P are "equivalent". Their DD (data direction) pins (J3 pin 3) should be tied at a little above 2.5V, (R9 220R and R74 390R )

Try removing the MC6889's ...

Also, check that J1 pins 1 and 2 (NMI and IRQ) are pulled properly " high" (by 4k7, R10) and R11)

Check if clock 02 (J1 pin 31) is oscillating...
Last edited by HOWARDHB on Thu Apr 17, 2025 5:36 pm, edited 1 time in total.
KlyBall 600D: 8K RAM, BASIC 1FIX, BASIC 3FIX, C1S Monitor Rom
KlyBall 610 : 24K RAM
KlyBall D-13 V2.0
MPI 51 - 5.25"
SAMSUNG SFD-321J - 3.5"
CHINNON FZ-506 - 5.25"
GOTEK with FLASHFLOPPY 3.46a
:mrgreen:
ronin47
Posts: 298
Joined: Thu Dec 14, 2023 2:17 pm

Re: My 610 board build.

Post by ronin47 »

HOWARDHB wrote: Mon Apr 14, 2025 3:08 pm ...strange indeed!

I note that U6 & 7 are not N8T28 , however, MC6889P are "equivalent". Their DD (data direction) pins (J3 pin 3) should be tied at a little above 2.5V, (R9 220R and R74 390R )

Try removing the MC6889's ...

Also, check that J1 pins 1 and 2 (NMI and IRQ) are pulled prooerly " high" (by 4k7, R10) and R11)

Check if clock 02 (J1 pin 31) is oscillating...
Are you referring to the 610? I don't have all the IC's so I haven't hooked it up with any power yet.

However if you're referring to the 600D then I have 8T28's IIRC. I'll have to go away and check this stuff, problem is I have a poorly Amiga 500 that is demanding my attention and workbench space as well!!!

EDIT:

Well just to confuse things, mine are labelled both MC6889P and MC8T28P...

Also, I would add that it makes no sense that a cable being plugged into the 600 would make it fail to boot. There is normally only an empty socket and the cable just extends it when it's not connected to the 610.
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HOWARDHB
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Re: My 610 board build.

Post by HOWARDHB »

[quote.Also, I would add that it makes no sense that a cable being plugged into the 600 would make it fail to boot. There is normally only an empty socket and the cable just extends it when it's not connected to the 610. [/quote]

I agree, it's a mystery, for now...
Do check that DD is in fact slightly above 2.5V with no bus drivers in the 600's U6 and U7 sockets.
KlyBall 600D: 8K RAM, BASIC 1FIX, BASIC 3FIX, C1S Monitor Rom
KlyBall 610 : 24K RAM
KlyBall D-13 V2.0
MPI 51 - 5.25"
SAMSUNG SFD-321J - 3.5"
CHINNON FZ-506 - 5.25"
GOTEK with FLASHFLOPPY 3.46a
:mrgreen:
ronin47
Posts: 298
Joined: Thu Dec 14, 2023 2:17 pm

Re: My 610 board build.

Post by ronin47 »

HOWARDHB wrote: Mon Apr 14, 2025 5:24 pm [quote.Also, I would add that it makes no sense that a cable being plugged into the 600 would make it fail to boot. There is normally only an empty socket and the cable just extends it when it's not connected to the 610.
I agree, it's a mystery, for now...
Do check that DD is in fact slightly above 2.5V with no bus drivers in the 600's U6 and U7 sockets.
[/quote]

Thanks Howard will do.
dave
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Re: My 610 board build.

Post by dave »

ronin47 wrote: Mon Apr 14, 2025 3:58 pm Also, I would add that it makes no sense that a cable being plugged into the 600 would make it fail to boot. There is normally only an empty socket and the cable just extends it when it's not connected to the 610.
A wire (or 40 of them) hanging off the main board with no connection at the other end acts as a stub and as an antenna. As a stub, a reflected waveform with a 1 MHz fundamental would have almost no effect for a 15 cm (~6") wire (or any wire less than 30 m, for that matter. As an antenna, though, the cable could be susceptible to RF interference up to 200 MHz, and depending on the capacitance of the line, this could get integrated sufficiently to interfere with normal operation. Even infrequent glitches can prevent a boot, especially with 40 lines.

What happens if you just place an uncrimped DIP socket connector in the socket, without the cable? If that's OK, then try a socket with a 12" cable. If that's OK, cut the cable down to the desire length. If that's OK, then place the other DIP socket connector on the free end.

I do know that if you attempt to connect an unpowered 610 board to the 600 board, your 600 will not boot. But that's not what is happening here, of course.

Nice build! Please keep sharing. . .

Dave
ronin47
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Re: My 610 board build.

Post by ronin47 »

dave wrote: Mon Apr 14, 2025 6:35 pm
ronin47 wrote: Mon Apr 14, 2025 3:58 pm Also, I would add that it makes no sense that a cable being plugged into the 600 would make it fail to boot. There is normally only an empty socket and the cable just extends it when it's not connected to the 610.
A wire (or 40 of them) hanging off the main board with no connection at the other end acts as a stub and as an antenna. As a stub, a reflected waveform with a 1 MHz fundamental would have almost no effect for a 15 cm (~6") wire (or any wire less than 30 m, for that matter. As an antenna, though, the cable could be susceptible to RF interference up to 200 MHz, and depending on the capacitance of the line, this could get integrated sufficiently to interfere with normal operation. Even infrequent glitches can prevent a boot, especially with 40 lines.

What happens if you just place an uncrimped DIP socket connector in the socket, without the cable? If that's OK, then try a socket with a 12" cable. If that's OK, cut the cable down to the desire length. If that's OK, then place the other DIP socket connector on the free end.

I do know that if you attempt to connect an unpowered 610 board to the 600 board, your 600 will not boot. But that's not what is happening here, of course.

Nice build! Please keep sharing. . .

Dave
Thanks Dave I appreciate the technical input, and it makes sense to me.

Unfortunately I don't have a spare dip plug to test it and I'd rather not disassemble my cable to try, but I'll see if I can think of something else to simulate it.

Hopefully I should have my missing parts soon and I can test it out powered up.

One question though, is it possible to run the 610 without RAM as mine is going to be a while arriving.

Thanks, and I'll keep sharing 😁
dave
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Re: My 610 board build.

Post by dave »

It is possible to run the 610 without RAM. But you won't be able to run OS65D with BASIC. I think even HEXDOS requires 12K. But you may be able to run PICODOS.
bxdanny
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Re: My 610 board build.

Post by bxdanny »

HEXDOS is the operating system that CAN run with just 8K of RAM. Pico-Dos requires 13k. (That applies to both OSI's Pico-Dos 1.1 disks and my "Enhanced" versions, although the version on the "Victory Software" disk can boot and run in 12k.)
ronin47
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Re: My 610 board build.

Post by ronin47 »

dave wrote: Tue Apr 15, 2025 3:44 am It is possible to run the 610 without RAM. But you won't be able to run OS65D with BASIC. I think even HEXDOS requires 12K. But you may be able to run PICODOS.
Thanks Dave. The primary objective being to get the 600/610 combo set up and running whilst I wait for my RAM to arrive, so it's good to know it'll run with no memory installed.
ronin47
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Re: My 610 board build.

Post by ronin47 »

bxdanny wrote: Tue Apr 15, 2025 4:10 am HEXDOS is the operating system that CAN run with just 8K of RAM. Pico-Dos requires 13k. (That applies to both OSI's Pico-Dos 1.1 disks and my "Enhanced" versions, although the version on the "Victory Software" disk can boot and run in 12k.)
Thanks, I won't be specifically trying to run anything immediately, just get the 610 up and running. Nice to know though.
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