MC68000 Pinout 51,52,62,63,64

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zChris
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Re: MC68000 Pinout 51,52,62,63,64

Post by zChris »

Hello all,

Here is where im at now:

I dont have EPROMS that can fit a splitted EmuTOS 192. I have made changes to the motherboard so i cant test the 6 roms that i used before. So what i have now is exxos DualTOS and decoder board. I'm pretty certain that both are working.

When i start the computer with only DualTOS board or with DualTOS and decoder board i get a white screen. I tried moving the jumper on the DualTOS board in both cases. I have the CE cable from Decoder board connected to the DualTOS board and bridged the booster ce select on the dualtos board.

I have measured the pins between the CPU (When it is on the decoder board) and the DualTOS board, this is the results i have gotten.

All the pins had below 1ohm. Voltage was 5.11 on pin1 and 28 on both HI/LO. Pin 14 went to gnd.

These pins below went to different pins on the CPU meaning that for example pin 11 on HI went to CPU pin 61 and pin 11 on LO went to CPU 5

HI/CPU|LO/CPU (NC = Not connected)
11/61|11/5
12/60|12/4
13/59|13/3
15/58|15/2
16/57|15/1
17/56|17/63
18/55|18/62
19/NC|19/NC
20/NC|20/NC

rest of the pins went to the same CPU pin.

/zChris
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exxos
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Re: MC68000 Pinout 51,52,62,63,64

Post by exxos »

IIRC CPU CLK & BG are buffered so there won't be a direct connection on those pins anyway.
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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zChris
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Re: MC68000 Pinout 51,52,62,63,64

Post by zChris »

Can leadfree solder be a problem? Not as good conductor or such ?

/zChris
zChris
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Re: MC68000 Pinout 51,52,62,63,64

Post by zChris »

Hello all,

Some progress have been made. After a lot of fiddlings i've been able to bootup in 1.04 while in 2.06 i get the atari logo and after awhile it says "Memory test aborted" and there are four bombs, this is with the original CPU. When i test with TF536 in 2.06 i get to the Atari logo and nothing more.

So it seems that TF536 and DualTOS with Decoder is working (hurray!).

Do you think it might be faulty RAM that makes 2.06 to cancell memory testing and bomb?

/zChris
zChris
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Re: MC68000 Pinout 51,52,62,63,64

Post by zChris »

after some more reading it seems i need to do the DMA fix https://www.exxosforum.co.uk/forum/viewt ... =17&t=1417

/zChris
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Re: MC68000 Pinout 51,52,62,63,64

Post by exxos »

206 will bomb after the logo if the floppy drive isn't plugged in... And you shouldn't really use leadfree solder with leaded stuff...
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
zChris
Posts: 194
Joined: Fri Nov 27, 2020 10:13 pm

Re: MC68000 Pinout 51,52,62,63,64

Post by zChris »

Ah, and here i thought i was being naturefriendly :/ Lesson learned
exxos wrote: Sun Mar 28, 2021 3:52 am 206 will bomb after the logo if the floppy drive isn't plugged in... And you shouldn't really use leadfree solder with leaded stuff...
Now i can bot into 1.04, and 2.06 fine with original CPU. But with TF536 the atari freezes after memory test. So a lot of progress have been made today. Sadly one of my motherboard had to take one for the team.

/zChris
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stephen_usher
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Re: MC68000 Pinout 51,52,62,63,64

Post by stephen_usher »

Do you have an ACSI drive plugged in? Are you using HDDriver 10?

I had something similar, admittedly with the PAK/3 ROM (TOS 3.06) and it turned out to be the HD driver boot block crashing out.
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ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
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zChris
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Re: MC68000 Pinout 51,52,62,63,64

Post by zChris »

Hello Stephen,

I have Goex and keyboard plugged in. And UBE ST2VGA adapter nothing else. I will try to jumper CDIS as that was a suggestion.

/zChris
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PaulJ
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Re: MC68000 Pinout 51,52,62,63,64

Post by PaulJ »

zChris wrote: Sun Mar 28, 2021 2:42 am Can leadfree solder be a problem? Not as good conductor or such ?
/zChris
Yes, leadfree solder solder is a pain in the A@#. Has a higher melting point and just doesn’t wet as well as 3% lead solder.
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