CPLD replacement for ZX8301

[Peter]

No the schematic is ok, which IC doesn't appear ?

E.g. the schematics contain an IC4, which is nowhere on the PCB pictures.

But if you make the previous more compact version available again, I prefer that anyway (if I decide to build one).

[lliont]

But IC4 is the AD724 it is there

https://hackaday.io/project/187455/gall ... 0bf7f92244

[lliont]

You must have looked at this picture at the project logs that is older but it is at the project logs not in the gallery

https://cdn.hackaday.io/images/8666461669120690876.jpg

Now I added it at the logs too to avoid confusion and anyway you don't need the pcb picture to build the project if you have the real pcb.

thanks for the info.

[Peter]

Thanks. By the way, crystal, trimmer, electrolytic cap and oscillator can not be ordered from the info given on the website and require guesswork. Some geometries or actual part numbers would allow people to get those more easily. (Not meant as criticism - I do understand if you lack the time.)

[XorA]

Looks like all this project needs now is Aurora mode implemented to have an Aurora workalike in combination with an SGC

The Autora screen area is at $4C0000. So in this ULA-socket project, the Aurora modes can not be implemented.

Ah yeah, suffered a brain crash there!

[lliont]

But you gave me an idea for a new project with the cpu on the ula board and a bus with all the ram controlled by the ula and then ula can use any part of the ram for video and the speed of QL will increase a bit more than I achieved with my latest ula pcb, by not having to refresh drams at all.
It won't implement the Aurora but can reserve memory for more colors or something else.

[Peter]

It won't implement the Aurora but can reserve memory for more colors or something else.

And you can not implement it, if your CPU still is the 68008. Which I guess from "speed of QL will increase a bit more". Otherwise it would increase much more. Aurora screen memory addressing depends on 68000 upward.

[lliont]

It won't implement the Aurora but can reserve memory for more colors or something else.

And you can not implement it, if your CPU still is the 68008. Which I guess from "speed of QL will increase a bit more". Otherwise it would increase much more. Aurora screen memory addressing depends on 68000 upward.

obviously

[Peter]

But you gave me an idea for a new project with the cpu on the ula board and a bus with all the ram controlled by the ula and then ula can use any part of the ram for video and the speed of QL will increase a bit more than I achieved with my latest ula pcb, by not having to refresh drams at all.

If you use an FPGA in that new project, you might even want to replace the 68008 by an FX68K core.
As you probably know, it implements a cycle-exact 68000 which can, with reasonable effort, be turned into an almost cycle-exact 68008.

[lliont]

I started a fpga (altera/intel cyclone IV) ULA project plus a PLCC52 68008 board.
QL sees 1920K of the on board ram but if a card with rom is present then it stops there counting ram, so with my qubide clone it stops at 832K.
It already supports what the cpld offered and the faster video memory and I hope I'll add a lot more taking my time.