exxos's Atari, Amiga & retro forum

@PaulJ I'm pretty sure that list isn't comprehensive, especially since each category will have sub categories

There may even be some missing.....

PhilC wrote: ↑Wed Oct 21, 2020 7:34 am Thanks @PaulJ , do you also have a guide for correct chip orientation?

Phil, I would have included an orientation guide but for fuses they can be inserted either way. I would watch out for the brass fuse though maybe insert the pointy end away from ya.

@PaulJ seems like reasonable advice.

PhilC wrote: ↑Wed Oct 21, 2020 3:36 pm @PaulJ seems like reasonable advice.

Just purchase the better part of two 1040’s and both had supplies with missing fuses. Assume the supplies are suspect but had to order fuses just not the ones pictured. I would guess a lot of the current ratings are bad. Don’t believe the flip top could do 130 amps not to mention some of the other ratings.

Re: NetUSBee
I thought I'd try it again in the STFM with TF536 and I monitored what the CPU actually sees.

Very interesting. It doesn't pull the bus down very well. It's extremely weak. Most of the bits hardly make it down to TTL low levels of voltage, and many don't.

stephen_usher wrote: ↑Mon Nov 02, 2020 9:10 pm Re: NetUSBee
Very interesting. It doesn't pull the bus down very well. It's extremely weak. Most of the bits hardly make it down to TTL low levels of voltage, and many don't.

Ya know that maybe a good clue. We have decreased the resistance values of the pull-ups which could cause a higher low if being driver with a weaker device. I've been playing with the bee on the H5 and part of the issue is the recycled cartridge connector. After a good cleaning and a lub with some electronic cleaner its much better. However its not a 100%... usually works booting from a cold system. But if its been on for some time it fails occasionally. Another funny thing is you can start it cold, exit and restart hours later and it works. Without that cold start its a top up if its going to start when warm.

Even 2.2K pull ups is only 2.2mA... What it using to drive the bus anyway ? if it cant pull down a couple of mA then its going to need some buffering to work properly.

Well I went to give Exxos's Trudie V5.2 a try and notices the only place I could put a tos rom was on the H4/H5 mother board under the supply which sorta sucks or use the Rom emulator. So I decided I needed another solution since I have quite a number of 27c010/27c020 chips laying around. I layed out another rom board to use with Trudie. I'll let ya know how it works when I get the boards. Was a pain laying it out in the limited space of a DIP 68k.

Well had a major Boner on the first layout. I got the PLCC socket layout from Mouser and used it as received. Yup how would they know what I'm putting in the socket but I wired it up as. Never guess it was pin configured as a socket 1-32.. My BAD.. So I actually used Exxos's Eagle tutorial to reconfigure the socket as an 27c020. I was able to cancel the dud and update the gerbers and added an adaptor to program the 27c020 PLCC in a dip socket.

So since I was delayed I threw in the Rom simulator and gave Trudie a test run to check it out in my H4. Works great and appreciate the smaller foot print. I was going supply a pic but not up for making a pic with 800 px.. Maybe a size limit would be a little user friendly. Never the less Trudie works fine in the H4 with the rom emulator.

@rubber_jonnie , I just noticed the picture below in one of your posts. Do you see anything suspectious about this picture? For me it looks like the vicious soldering iron has put out bait. You innocently goto pickup the board up and ZAP !!! the iron will strike and who knows what damage will occur to your remaining fingers. Please exercise extreme caution Rj... you only have ten fingers.