Percom & ATR-8000

[moonlight_mile]

Hey all,

I have 3 Percom drives and a set of drives connected to the ATR.

 

In normal circumstances in the 80s I am guessing it would have been very unlikely to have both a percom and atr connected to the same Atari, but in these days things are different.

 

Sooooo, I have an sio splitter and had both a Percom drive and the atr plugged into the splitter. Percom works fine, but if I turn off the Percom and turn on the atr and try to use those drives it doesn’t see the drives.

 

This is no big deal but does anyone know why the Atr won’t boot with a Percom in the chain?

[_The Doctor__]

Not sure if the percom isolates sio or is isolating sio properly... If you have a 1050 or other drive on with the percom still connected is there an issue?

What happens if you pull the percom power cord?

[moonlight_mile]

Not sure if the percom isolates sio or is isolating sio properly... If you have a 1050 or other drive on with the percom still connected is there an issue?
What happens if you pull the percom power cord?

Well I don’t have a 1050 but I have an xf551 and that one works with the perc on the sio chain. I didn’t get a chance to try it with the percs unplugged but I have a power strip with individual switches for each outlet on order (I want to use they because getting to the back of all the drives to power them up is a real pain in the rear, this way I can power them individually from the power strip. ) when I get that installed I will give it a whirl.

[_The Doctor__]

the ATR8000 works with the XF as drive1/2 on the chain and powered off though?

[moonlight_mile]

Yupper.

[_The Doctor__]

can you set the percom id's ABOVE 1/2?

 

ATR8000 sets up it's drives based on poll/what it sees at boot... if I recall correctly

If you are changing who is powered up then you press the ATR8000 reset button or power cycle the ATR8000

I don't think there is a utility to add or remove assigned ATR8000 drives while in operation. I don't remember that at least... but power off drives and reset or power cycle sounds like something we did.

 

If you start from a fully powered down system and never turn on the percoms are you still blocked? Don't forget to leave enough time for power to dissipate from the circuits....

Edited February 14 by _The Doctor__

[moonlight_mile]

I think I might have done that in the past but can’t remember. I will go down and try it.

I just realized I had my fujinet plugged in, I might be wrong but I may have at one time had of unplugged (didn’t have it yet) and it may have worked. I will go down and fool around with it a bit.

I’ll let you know if it works. Like I said it is no big thing I was just hoping I could have everything plugged in to the sio and just power on or power off what I wanted to use.

[moonlight_mile]

I gave it a try. None of the percs were plugged into power and even with the fujinet out of the loop it won’t boot. Weird huh? Like it said it is no biggie. I ordered another sio “hub” and going to connect all the percoms into that one as to isolate them from the rest of the systems.

[1050]

When I had a real atari system, I would run it with a four drive stack with two D1: and two D2:, using the power switch on each drive to activate which pair I wanted. I found the only way to reliably allow this kind of swap to occur was to do the power down of drive to be abandoned, power up the drive to use and then most importantly do a RUN at 0x07E0 to effect a proper SIO init on all the disk drives and slap DOS up side the head while I'm at at. That might be what you are missing? Until I got into that habit I would often have the most confusing array of issues trying to use the newly powered up drives. At the top of that list was a drive that failed to do anything like it wasn't there at all.

[moonlight_mile]

Holy moley, jumping through all those hoops. Wow. I just wanted everything connected through one sio cable.

I will play around a little more with it in the next few days see if I can find any easy way of doing it.

[+kheller2]

3 hours ago, moonlight_mile said:

Holy moley, jumping through all those hoops. Wow. I just wanted everything connected through one sio cable.

I will play around a little more with it in the next few days see if I can find any easy way of doing it.

You should be able to do it with a single SIO line ...  no splitter needed, they could all be daisy chained.  The fact that there are conflicts when you have them all on the bus lends itself to this troubleshooting session.

 

[moonlight_mile]

I have been playing around with it. It appears not on the atr doesn’t like the percoms but the Fuji net won’t boot with the percs on the sio chain.

Still playing around to see if it is just one of the percoms or all but something is hogging the sio bus.

[_The Doctor__]

it's your percs

 

[Mark2008]

On 2/17/2021 at 7:23 AM, moonlight_mile said:

Holy moley, jumping through all those hoops. Wow. I just wanted everything connected through one sio cable.

I will play around a little more with it in the next few days see if I can find any easy way of doing it.

haha, I like that idiom "jump through hoops".

If I'm literally at the circus I might enjoy watching a trained bear jump through hoops.  If I'm the bear being trained - hard pass.  Although that sort of answer doesn't lend itself well to troubleshooting discussions.  e.g. have you tried turning off the drive and never using it again?

 

ok, that's my sense of humor - nevermind.  Good luck with the ATR/Percom situation. 

[Mazzspeed]

The problem with serial interfaces these days is the fact that pull down resistors act as pull up resistors on the serial bus when drives/peripherals are connected a certain way, making peripherals, usually drives, invisible when the device containing the resistors is turned off. I wonder if this could be the case here?

Edited February 25 by Mazzspeed

[moonlight_mile]

I was thinking of checking the sio lines and see if there is 1 line that is causing the issue. I was going to disconnect that line from the sio chain and see if I can still use the percoms with the atr and fujinet.

Do you think this might cause damage to the percoms or the other peripherals if a line is disconnected?