Address decoding & some simple sequential logic

[Badwolf]

Afternoon all.

What would the forum think is the best approach at the moment for some common hardware modding tasks.

Specifically I'm thinking about

1) address decoding;
2) some fairly simple sequential logic.

All at 5V.

Probably if this were the late 90s I'd have said PALs or GALs would be the best option. But I don't know if they're still widely available.

Recently for larger projects I've thrown XC95 CPLDs at the problem but that has downsides in that it needs supporting circuitry and those 5V tolerant ones are going out of life which means modern ones will need even more circuitry.

So my mind's kind of gone back in time for an address decoder and I'm thinking about 4-way ANDs and hex NOT gate combinations. For the basic sequential logic (think six lines, perhaps), I'm scratching my head.

What's the future-friendly way to do these retro tasks, you think?

Atmel still seems to make things it calls EEPLDs. Anyone any experience with those?

BW

[stephen_usher]

16V8 GALs are still available, just. You can use a set of diodes as a multiple OR gate :-)

You can even use an EPROM and feed the address lines in and have a truth table.

[olivier.jan]

I’m using 16v8 and 22v10 a lot, apart from the crappy Wincupl software, it’s still save you a lot of time.

[Badwolf]

16V8 GALs are still available, just. You can use a set of diodes as a multiple OR gate :-)

I’m using 16v8 and 22v10 a lot, apart from the crappy Wincupl software, it’s still save you a lot of time.

Thanks both. What do you use for a programmer? I've seen mixed answers as to whether the venerable TL866ii can do the job.

BW

[stephen_usher]

16V8 GALs are still available, just. You can use a set of diodes as a multiple OR gate :-)

I’m using 16v8 and 22v10 a lot, apart from the crappy Wincupl software, it’s still save you a lot of time.

Thanks both. What do you use for a programmer? I've seen mixed answers as to whether the venerable TL866ii can do the job.

BW

The TL866 is fine for 16v8s, just choose the correct Atmel model. Getting it wrong will mean that the programming fails, which is probably what's happening in those reports.

[olivier.jan]

TL866 II is working fine with the ATF22V10 and the ATF16V8 as mentioned by Stephen. I’ve read the reports and my understanding is that it concerns the original TL866, the second version TL866 II has no such problems.

[Badwolf]

Corking. Thanks, gents.

I'll put that on my list of things to experiment with for a couple of my next projectettes. :dualthumbup:

Cheers,

BW

[exxos]

I use the ATF1500 series on stuff. Basically a big GAL. Use the 1502 on my 16mhz booster and 1508 on the SEC booster, TRUDIE and Flashy clock.. It's all 5v.

[Badwolf]

I use the ATF1500 series on stuff. Basically a big GAL. Use the 1502 on my 16mhz booster and 1508 on the SEC booster, TRUDIE and Flashy clock.. It's all 5v.

What's the programming chain look like?

WinCPL, I presume and specialist programmer, is it?

Ta,

BW

[exxos]

WinCPL,

Yes.

I presume and specialist programmer, is it?

Yes you need the proper Atmel one which was hard to find and not cheap at around £100 IIRC.

EDIT:
Looks like someone on evilbay has some...

https://www.ebay.co.uk/itm/204791643940