Okay let's try that. Do you have schematics and placeplan for me, so I can see where the JTAG lines are?
FPGA replacment for the ZX8301 ULA and more
Re: FPGA replacment for the ZX8301 ULA and more
Re: FPGA replacment for the ZX8301 ULA and more
Possible, I just had a hasty look without checking what kind of access it was.
Yes, the lowered slewrate is important. Even that is still fast for a QL mainboard.
I don't expect this to cause my specific problem though.
This also indicates we might have a DRAM related timing issue. For example max. transition times of "my" DRAM is 100ns, of "your" DRAM 35 ns.
Re: FPGA replacment for the ZX8301 ULA and more
You need to supply power to the board, I do it on the QL but don't take the risk.
Or send them to Stephan who has done this before.
Leon
Projects: https://hackaday.io/projects/hacker/357657
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Re: FPGA replacment for the ZX8301 ULA and more
Hi,
I have a Tetroid Power Regulator in place of the standard QL power Regulator and heat sink: That is the only difference I can see, I can not see any problems with the ULA board send to me.
Is there any commands I can try to test the operation of the ULA?
If I am disturbing the discussion, I am sorry.
I have a Tetroid Power Regulator in place of the standard QL power Regulator and heat sink: That is the only difference I can see, I can not see any problems with the ULA board send to me.
Is there any commands I can try to test the operation of the ULA?
If I am disturbing the discussion, I am sorry.
Regards,
Derek
Derek
Re: FPGA replacment for the ZX8301 ULA and more
Thanks for the info Derek
Programming the cpld
Programming the cpld
Leon
Projects: https://hackaday.io/projects/hacker/357657
Projects: https://hackaday.io/projects/hacker/357657
Re: FPGA replacment for the ZX8301 ULA and more
You could check if you really also have KM4646A-15 DRAMs.Derek_Stewart wrote: ↑Wed Jan 24, 2024 9:17 am Is there any commands I can try to test the operation of the ULA?
I found a parallel port adaptor, which will probably no longer be supported. So I have ordered a USB one.
The cost of a programming adaptor does not justify shipping to Stephan and back. Especially as we don't know how many programming cycles we will need until it works here.
Do I need the bloated Quartus II installation, or is there a leaner programming tool?
Re: FPGA replacment for the ZX8301 ULA and more
I use Quartus 13.0.1 for the older cpld programming, newer quartus versions may not support MAX7000S family.
Some usb blaster clone's driver crashes windows 10, work well with earlier versions of windows.
Some usb blaster clone's driver crashes windows 10, work well with earlier versions of windows.
Leon
Projects: https://hackaday.io/projects/hacker/357657
Projects: https://hackaday.io/projects/hacker/357657
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Re: FPGA replacment for the ZX8301 ULA and more
I have TMS4164-15NL DRAMs soldered to the QL board:
Regards,
Derek
Derek
Re: FPGA replacment for the ZX8301 ULA and more
Well there is no doubt it has to do with dram but is it that all QLs with KM4646A-15 DRAMs have the incompatibility problem?
I had an idea, in my QL I installed sockets for the drams so if I find KM4646A-15 DRAMs I can directly test them.
Are you sure the dram type is spelled correctly Peter? I think you mean KM4164A
The KM4164B-12 work without a problem you can see in older pictures that half of the drams in my issue 5 QL are this kind.
I found also 3 ics KM4164B-15 to test
I had an idea, in my QL I installed sockets for the drams so if I find KM4646A-15 DRAMs I can directly test them.
Are you sure the dram type is spelled correctly Peter? I think you mean KM4164A
The KM4164B-12 work without a problem you can see in older pictures that half of the drams in my issue 5 QL are this kind.
I found also 3 ics KM4164B-15 to test
Leon
Projects: https://hackaday.io/projects/hacker/357657
Projects: https://hackaday.io/projects/hacker/357657
Re: FPGA replacment for the ZX8301 ULA and more
Well I reproduced the problem.
Initially QL booted but after a while problems appeared i.e. random pixels on the screen, then I made some changes and now it works.
I think I solved it but I'll give it some more time.
Tested with only 3 of these @##$% dram ics.
Initially QL booted but after a while problems appeared i.e. random pixels on the screen, then I made some changes and now it works.
I think I solved it but I'll give it some more time.
Tested with only 3 of these @##$% dram ics.
Leon
Projects: https://hackaday.io/projects/hacker/357657
Projects: https://hackaday.io/projects/hacker/357657