8501 replacement for C16 Plus4: work in progress...

[eslapion]

O.K., I am confused. I just ordered from https://lotharek.pl and the price I paid was 43.58 Euros, not including shipping.

I took a quick look at this 6502 to 8501 adapter and it uses a set of 3 xx245 buffers along with a XC9572XL CPLD. Now, this CPLD is 5V input tolerant and signals at 3.3-3.6V so the buffers are absolutely not needed. This is another nice programmer without the necessary knowledge about different technology interfacing.

See: https://www.allaboutcircuits.com/textbo ... ge-levels/

[MCes]

The C16 bus, as the C64 one, has to be shared by CPU and video chip, so the 6510 and the 8501 are able to put their bus lines in high impedance.
The 6502 is not able to do it, than (as in VIC 20 too) a buffers wall is needed for performing this.

Instead my project use a specific CMOS version that can do it, this reduce the HW complexity but increase the firmware complexity.

I suggest to anyone, and especially to those who know the subject only superficially, to offer their doubts in the form of a question or possibility and not with sharp judgments.
this will avoid creating the right resentment in those who have developed the project, but also making a bad impression of who want to teach others what he don't know.

EDIT:
This thread is specific to my project,
who want to talk about other projects can open another thread and don't posting on this one,
thanks

[eslapion]

The C16 bus, as the C64 one, has to be shared by CPU and video chip, so the 6510 and the 8501 are able to put their bus lines in high impedance.
The 6502 is not able to do it, than (as in VIC 20 too) a buffers wall is needed for performing this.

Correct. I just assumed the XC9572XL, which has 64 pins, would be used for that instead of having 3 additional logic buffers.

This thread is specific to my project,
who want to talk about other projects can open another thread and don't posting on this one,
thanks

My apologies.

[orion70]

I'm not aware of the TED being reproduced (although that would be awesome).

TED might be on the horizon:

https://www.forum64.de/index.php?thread ... ous-video/

See some news about the development of a a commercial TED replacement HERE.