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1 Meg Super AMS Discussion Thread


Omega-TI

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I can see a number of use cases for that, Rich. I also have a random question: which byte is written first? I ask this because the first byte written will be the one that is latched, and would be in the value range of >00 to >0F. I just wanted to make sure I have the byte data in the right order in my earlier post. . .

In my GPL Code I move just one byte into the Even Address to change a page:

ST >0A,@>4014

 

Same thing you can do from XB:

CALL LOAD(16404,10) ! Or move >0A at mapper >4014)

 

Assembly has to move a word but GPL and XB do not need to do that.

Your change adds another value to make it a word as it has always been just a byte for me on SAMS.

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  • 3 weeks later...
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  • 7 months later...

Just got my bare board last week and I ordered my parts for the SAMS based on the list under the board on ArcadeShopper. While assembling the board, I notice that the 74LS04 and the 74LS688 have been replaced by 74LS34 and 74LS683. Can someone explain the difference, please?

Edited by klrw111-78
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Just got my bare board last week and I ordered my parts for the SAMS based on the list under the board on ArcadeShopper. While assembling the board, I notice that the 74LS04 and the 74LS688 have been replaced by 74LS34 and 74LS683. Can someone explain the difference, please?

 

 

Sorry--- Just read the full thread and found the answer...

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  • 3 months later...

I was testing ICs for use on this card with a MiniPro TL-866. I understand that the Minipro will not test three of the chips used on this card, but it should test the static ram chips. My Minipro begins the process of checking the rams, but ends up giving a USB communications error 32 before finishing. I have tried chips by Hitachi and Alliance and have the same issue with both. I have installed the latest software and drivers. Has anyone else experienced this issue?

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I was testing ICs for use on this card with a MiniPro TL-866. I understand that the Minipro will not test three of the chips used on this card, but it should test the static ram chips. My Minipro begins the process of checking the rams, but ends up giving a USB communications error 32 before finishing. I have tried chips by Hitachi and Alliance and have the same issue with both. I have installed the latest software and drivers. Has anyone else experienced this issue?

I can try to test a few and see if I get the error, I believe I have tested some bad and good ones in the past (6 to 8 months ago) and they tested correctly.

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I haven't had any problems in testing RAM for the 40 or so SAMS boards I built, but all of my RAM came directly from Mouser, so it wasn't an aftermarket purchase. For that matter, I never even had to run a chip test on one of them, as they all worked on initial installation (unlike some of the LS chips--I found about a dozen bad chips while building those boards, mostly LS612s).

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Getting back to troubleshooting my SAMS card. I bought a mini-pro and tested all my chips expect for 3, and all tested OK. When the card is installed and powered on everything seems to be working OK. When I attempt to load something that uses 32k memory, the led on both the memory card and the disk controller light up and system has to be rebooted. I end up with a trashed disk image. Since I discovered I damaged at least 2 traces during my desoldering efforts (didn't socket everything at first), I want to confirm the schematic version to use for additional troubleshooting. Is this the correct one for the current revision (note that the 555 is not shown)?A3-SAMS-P1(R4).pdf

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Yes, that is the closest match to your version of the board. I need to add the 555 circuit to that one (it is mostly independent of the rest of the board, so it should not be what's giving you issues here. One additional thing I would check here is the LS612. I get way too many weird symptoms from bad 612 chips (About one in six of the NOS chips I've picked up for these was bad).

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