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Re: CPLD replacement for ZX8301

Posted: Mon Aug 14, 2023 7:21 pm
by lliont
yes I use 16K of ram for one or two bits more color

new plot command for the 64 colors:
1692311331404.jpg

Re: CPLD replacement for ZX8301

Posted: Tue Aug 15, 2023 8:47 am
by Cristian
Impressive, great job!

Re: CPLD replacement for ZX8301

Posted: Tue Aug 15, 2023 10:09 am
by lliont
thanks,
The extra ram is inside the fpga (as is the sprite ram) and so it can be accessed in parallel with the other video ram without any extra delay.
I believe that all the address space I used for new features can be reclaimed and be available to external cards with the standard pull hi the DSMC method, I tested this with the 2MB onboard ram and the qubide clone with its own ram that works perfectly.

Re: CPLD replacement for ZX8301

Posted: Tue Aug 15, 2023 11:41 am
by Peter
What do you mean by "two brightness levels for both QL standard video modes"?
For Mode 8 one can redefine the Flash bit, but Mode 4 lacks that kind of extra bit.
(Probably I have overlooked something - sorry for not completely following the thread.)

Re: CPLD replacement for ZX8301

Posted: Tue Aug 15, 2023 5:32 pm
by lliont
Peter wrote: Tue Aug 15, 2023 11:41 am What do you mean by "two brightness levels for both QL standard video modes"?
For Mode 8 one can redefine the Flash bit, but Mode 4 lacks that kind of extra bit.
(Probably I have overlooked something - sorry for not completely following the thread.)
This apply to the whole screen (standard video modes), if you don't use the extra color and since there is an extra bit on the resistor dac you can use it this way, not much of a feature but will be available also in the fpga version.

Re: CPLD replacement for ZX8301

Posted: Sun Dec 10, 2023 9:09 pm
by bwinkel67
I just saw this 8-minute video (posted 8 months ago) by Danieel Terdina about an FPGA replacement for the ZX8301 he was designing:

https://www.youtube.com/watch?v=7EizW3ZWNqc

Re: CPLD replacement for ZX8301

Posted: Mon Dec 11, 2023 12:27 pm
by lliont
This is very nice , it runs on the mister QL emulation core with a very powerful and expensive fpga, also check the topic: FPGA replacment for the ZX8301 ULA and more

Re: CPLD replacement for ZX8301

Posted: Mon Jan 29, 2024 8:55 pm
by tetroid
Hi.
Does anybody try this CPLD replacement to use with the SGC ?
I see a lot of artefacts on the screen.

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Re: CPLD replacement for ZX8301

Posted: Mon Jan 29, 2024 9:10 pm
by lliont
Peter tried it and it didn't work with SGC. I don't have a SGC to test with.
You built one yourself from the project page ?
I think you have the older version, the compact version didn't run on Peter's QL + SGC.
I have tested it with qubide and a M.Peripherals floppy controller also it worked with Trump Card 896K in Derek 's QL.
Unfortunately seems that it doesn't work well with SGC (yet).
I have made another version with 128K static ram on the board replacing the dynamic ram, also not tested much, not with SGC.

Re: CPLD replacement for ZX8301

Posted: Mon Jan 29, 2024 9:41 pm
by tetroid
I use ZX8301_160smd.zip from the post :
lliont wrote: Wed Jan 25, 2023 5:41 am Very good!
Try the last version of program for your pcb version I attached. I fixed a video bug since we talked.

AD724 version, metal oscillatos is temporary solution :)
4-pin connector - power for programming.

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lliont wrote: Mon Jan 29, 2024 9:10 pm PI don't have a SGC to test with.

Unfortunately seems that it doesn't work well with SGC (yet).
Possible you agree I ship the SGC clone for you to test ? Free for hardware developer.