I think what I actually said was that I *didn't* think that part was made in a direct equivalent CMOS version.

Right, I mispoke, what I meant was links for the similar parts.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Ya that's what I have set up, I'll attach and image to the end of this.


whoops, ya, I meant a23



I'll go back to the article, after I read that it was used for phase matching I had moved away from it, since msot of the PLLs on mouser were smd packages anyway.

EDIT: forgot the picture

So I added in a second 4M module, just to see how the schematic would look (haven't moved back to the PCB yet, want to get the clock situation sorted). and I settled with the circuit at the end of this for the WE and OE connections, to maintain only max 3 gate delays for both devices (as opposed to 4 on the second, having to invert A23 before sending it to the NAND).



EDIT: just to be clear, the WRITE and READ signals in my last post are active high, these signals are WRITE\ and READ\ active low. ( it can be hard to see the lines above them)

Just as an aside, you certainly don't need a 66MHz 486 to run DOOM.

I routinely played it on a 486sx 25Mhz laptop back in the day, and it was developed on a 25Mhz '040 NeXTStation.

Is a 20Mhz '816 enough? I dunno, but you certainly didn't need a 66Mhz machine to play DOOM back in the day.

Huh, I'm too young to have played it on the first computer I used (a Pentium II running around 300Mhz) but I have it emulated on a pi powered arcade machine.

20mhz is going to be tough to hit, I'm hoping that I can optimize this well enough to be able to run it though.

So I just found this which seems perfect, but it's resistance controlled, and I'm not sure if it can be changed while live yet. Thoughts?

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Or use a digital potentiometer. If you get a non-volatile kind, it will remember the setting when the board is powered down.

Some recent ideas in this (long!) thread which might benefit from new dedicated threads:
- continuously-variable clocking of a 6502 system
- porting DOOM to a 6502 system
- Mouser's filtering mixes up surface-mount and through-hole

Sweet, so then I can probably use this just fine, the rise time on it looks pretty decent too.

The via idea I'm not sure about, it seems like a waste of via pins for clock control, I may try and find another way to switch out resistance on it.



This is probably what I'll do, the only issue with a non volatile one would be setting a too high clock and not being able to set it back or save myself by just resetting. Also, at power up it needs the slow clock, so if I had a power failure it wouldn't be able to reboot.

Still though, digital pot is probably the way to go, I just wasn't sure if I could change the frequency live.



Good idea, I'll post some more threads about the individual ideas to keep things organized, should I still post them in newbies? Or elsewhere?

You could do a jumper in series/parallel so you have the option for manual override.

Great! Not Newbies, I think - this is not getting-started stuff. Choose Hardware or Software forums if it's obvious, or General otherwise.

I actually already did that, after I realized that was probably the correct option, mouser is in general, doom in programming, and clock in hardware