exxos's Atari, Amiga & retro forum

exxos wrote: 27 Nov 2018 18:03 Now makes me wonder how long I have actually had this problem for :roll:

That would really suck if this was the case of most of your booster issues

Icky wrote: 27 Nov 2018 18:10 That would really suck if this was the case of most of your booster issues

We'll see how all my testing goes...

I can accept they may be 15ns parts for example when they are printed as 7ns parts.. I did a lot of diagnostics on the original V1 booster. Where it really did not matter if they were 7ns,15ns,25ns parts. But of course every single one was printed as a 7ns part.

I thought that would be the end of it, but obviously there is more to this chaos than simply incorrectly printed speeds.

So about 7 out of about 20 GAL's worked on the lot I got last week..

I only had 6 original GAL's, all 6 tested OK.. but not enough left to batch test them, so jury still out on those...

I have ordered chips from various sellers to see if I can hit on some good ones somewhere..

I took out a GAL from one of the red boards, and fitted it to my test board, and it was iffy at best. It would only work at 8MHz otherwise. So GAL went in the bin.

I put in the board a GAL which tested fine in my test board, and its booted up and seems to be working fine now.

So looks like I have a mission to change the GALs on the boards I made up this week. Maybe this will be the end of all this sage finally then!

Well spotted. Is there By other solution for Gals these days? Like going to smt or a different ic all together?

Forgottenmyname wrote: 27 Nov 2018 22:15 Well spotted. Is there By other solution for Gals these days? Like going to smt or a different ic all together?

Ages ago I did a adapter for a Atmel and Altera PLD. They more expensive, but I guess they work... https://www.exxosforum.co.uk/forum/viewt ... =76&p=1501

Was trying to keep size and costs down by using a normal GAL. But bit late in the day to think about using a different PLD now :(

If I ever did a new design (likely won't happen) I probably would use a larger Atmel chip (like the SEC booster) then route the address lines to decode ROM faster.. Move the CPU over to a SMT socket, Make the header pins contact on the inside of the PLCC socket.. Though with a large PLD and SEC design basically done, it would be better to use the SEC CPU on a future booster.. Then its a much larger PCB, likely be more layers etc.. But then we talking of another years work when I hardly have time to work on the SEC booster as it is :(

Its why I say I am not doing anymore STE stuff after this booster, I mean this should have been a super simple project and its been weeks of chaos :( I really want to get back to the STF project full time...

Totally understand, so essentially you need enough working Gals to get the ste boosters you have finished and that's that.

Good luck with the ones you're waiting on then.

I've got enough GAL's to complete the 8 ish ones I have... but doesn't still mean they will work after I swap the GAL's.

I will spend 2 more days on these (not around much tomorrow though) and what ever is working goes in my store.

..and this red board on test has just locked up :roll: This is acting like the CPU is crapping out, so may try a 32MHz OSC in it if it keeps on doing that... I think in relation to CPU "over heating" its not helping as this booster runs at constant 36MHz. With the V1 booster, it basically spent half of the time in 8MHz mode, I half think that was a better design overall. But of course that had its own issues as well.

Though I am thinking these things are just more trouble than they are worth. Seems to be 1 step forward, 2 steps back all the time with them all the time :roll:

Will see how these last few boards pan out, but I think its getting very close to me abandoning this project, otherwise I will never get anything else done.

EDIT:

OK 32MHz didn't help.. So I'm back to blaming the GAL again... I am going to leave the GAL's running in my test board for a lot longer.. I'm thinking as they warm up its also causing them to fail.

So a new gal failed pretty quick. My old stock gal has been running for about a hour. So I think I'm just going to bin all these gals. Its getting stupid to have to pre test them all like this.

BUT.

https://uk.farnell.com/microchip/atf22v ... t=Atf22v10

I forgot those are still available..

The problem is they have a power down pin on pin 4 which I can't figure out how to disable. But I'm going to order 10 and see if I can reroute whatever is on pin 4 to another pin and then I can tie pin 4 to 5v.

I think its more than clear that these gals from China are just not worth bothering with anymore. They must be defective parts somehow. Its not like the atmel gals are costing huge amounts anyway.

My only concern is if they don't work with my booster for some odd reason.. I don't see any reason for them not to work.. But never know until i try some out...

PD pin configuration is controlled by the design file, and appears as a separate fuse bit in the JEDEC file. When the power-down feature is not specified in the design file, the IN/PD pin will be configured as a regular logic input.
Note: Some programmers list the 22V10 JEDEC compatible 22V10C (no PD used) separately from the non-22V10 JEDEC compatible 22V10CEX (with PD used)

It does seem strange you even get problems with PD - if you're not specifically trying to use it it should not be an issue.