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Kyle22

ATR-8000 (and other) CP/M System disks here

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Anything is possible.  This is a weird error.
 
Best,
 
jeff

I am going to give that a shot. I just have to re-teach myself how to use the eprom programmer. I had to get one that does the 25volts. It is a bit different than the other one I have (and everybody else has).

I have noticed something with my 1797 chip. It looks as though it might be a burned prom. Is that possible? I attached pics of my original dead 1797 and the new 1797 I got. I doubt this is the issue but it just struck me as odd that they were clearly different packages.

ef45c5db52fc2e82bf4199fd4e03b729.jpg
5b333113a0740af0a5671323f1092009.jpg

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16 minutes ago, moonlight_mile said:


I am going to give that a shot. I just have to re-teach myself how to use the eprom programmer. I had to get one that does the 25volts. It is a bit different than the other one I have (and everybody else has).

I have noticed something with my 1797 chip. It looks as though it might be a burned prom. Is that possible? I attached pics of my original dead 1797 and the new 1797 I got. I doubt this is the issue but it just struck me as odd that they were clearly different packages.

ef45c5db52fc2e82bf4199fd4e03b729.jpg
5b333113a0740af0a5671323f1092009.jpg

That is normal.  I don't know why some are like that and others not, but I have both kinds and they are interchangeable.

 

Best,

 

Jeff

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28 minutes ago, moonlight_mile said:


I am going to give that a shot. I just have to re-teach myself how to use the eprom programmer. I had to get one that does the 25volts. It is a bit different than the other one I have (and everybody else has).

I have noticed something with my 1797 chip. It looks as though it might be a burned prom. Is that possible? I attached pics of my original dead 1797 and the new 1797 I got. I doubt this is the issue but it just struck me as odd that they were clearly different packages.

ef45c5db52fc2e82bf4199fd4e03b729.jpg
5b333113a0740af0a5671323f1092009.jpg

You can use pretty much any burner.  You have to make a little adapter that disconnects the program power legs from the burner and provide separate power.  That is as easy as running  24 volts to the pin in question.  You disconnect them from the burner as the burner has no use for them in this configuration and if left cfonnected you would be pushing 24 volts (a common and easy to find power pack) into the burner itself, which is not wanted. :-0

 

Best,

Jeff

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Struck out again. I don’t know what else it could be. I did order one of those z8430 chips but it looks like that is for the printer port.

 

I broke down and ordered another few 1797s it’s gotta be that chip.

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On 8/31/2020 at 3:43 PM, moonlight_mile said:

Been playing around with the atr. Got the old 3.5 drive from my st running nicely and the other drives I hook up run nice.

 

Now the issue. It seems as though if I try to read/write/format in double density it chokes. I only discovered this because I was trying to create cp/m disks. But it appears any sector copier I try it needs to write the disks in double density. I was able to write them with the xf551 but it never seems to work with any of the drives connected to the atr.

 

Is there a jumper on the atr I am missing? Seems really weird that it does everything in single density but it chokes in DD.

 

I have the terminator in the drive, I try to index a double density disk, nada.

 

Any ideas?

Have you tried the XF mech connected to the ATR?

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Have you tried the XF mech connected to the ATR?

I haven’t tried that. I have thrown almost all my drives at it. They all do format double on the Percom controller. I have another 3 1797s on the way. If those don’t work out I will try the xf. Drive.

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It for sure isn't the mechs.  If they format in SD they will format in DD.  Alignment can sometimes be a fault, but it is RARE and certainly would not present with multiple drives.  You have some kind of logic fault or, perhaps, as you said, a corrupt eprom.  That was a pretty good guess and easy enough to validate.

 

Best,

 

Jeff

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On 8/31/2020 at 3:43 PM, moonlight_mile said:

Is there a jumper on the atr I am missing? Seems really weird that it does everything in single density but it chokes in DD.

 

Any ideas?

There's not a jumper but there is a density select pin (pin #2) on floppy disk interfaces.   Do you have a second cable you can use for testing? You can also check the continuity of pin 2 through the cable

 

I'm not a hardware guy (nor a software guy) but I guess the next thing that would need testing is the circuit behind pin 2 of the card edge connector of the ATR8000.

 

-SteveS

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There's not a jumper but there is a density select pin (pin #2) on floppy disk interfaces.   Do you have a second cable you can use for testing? You can also check the continuity of pin 2 through the cable
 
I'm not a hardware guy (nor a software guy) but I guess the next thing that would need testing is the circuit behind pin 2 of the card edge connector of the ATR8000.
 
-SteveS

That is one of the few things I didn’t do. I will tone it out. I know pin 37 on the controller chip is the density select so I assuming that should connect to pin 2 of the card edge of the floppy/cable.

I have tried a few different cables and I do think I toned out my cable so I think that should be good. I will re-tone it just to make sure.

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I didn't think the Density Select line applied here, the schematics don't show it (unless I'm blind).  Can you read a DD disk formatted in another drive?  I'm curious if there is an issue with Side Select.  When formatting does it seem to format then bomb out on the verify?

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I didn't think the Density Select line applied here, the schematics don't show it (unless I'm blind).  Can you read a DD disk formatted in another drive?  I'm curious if there is an issue with Side Select.  When formatting does it seem to format then bomb out on the verify?

It won’t read a double density disk at all. I have tried formatting them on all my other drives.

It will format double sided, but only in single density.

I know pin 37 goes somewhere on the schematic but I didn’t see it going to the card edge either but I thought I would check.

I am a beginner/novice at reading schematics but the one I have does show pin 37 (indicating s/d) going into one of the 74 logic chips. 10b22c3dc761cc9cde644feb8b085441.jpg

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2 hours ago, moonlight_mile said:


It won’t read a double density disk at all. I have tried formatting them on all my other drives.

It will format double sided, but only in single density.

I know pin 37 goes somewhere on the schematic but I didn’t see it going to the card edge either but I thought I would check.
 

Keller2 is correct.  Card edge Pin 2 is unconnected.  I took out my ATR8000's PCB and confirmed it.

 

I looked at floppy drive pinout, saw that density select line, and just assumed that it might be the issue. 

 

 

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I toned a bunch of traces and stuff on the board and the cable. They all seem to tone out. From what I can tell. However, while looking at the chip it appears from the top that there is some discoloring by pin 37 and 36. Yet if I pull it out and look at it on the side it looks fine. Those pins do connect to the board in the socket but they do look a little funny.

a95a2bda12838fe431ab8bd70a679c53.jpg
2bf795fc7a4d43499dfbdac641255b84.jpg

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What about RAM?  If this were a doubler 1050 or some other drive conroller, I'd suspect the sram.

 

The ATR8000 uses DRAM, but say that one of your drams has a stuck bit smack dab in the area reserved for the disk controller?  You might try swapping for a known-good set of 4164's, or 41256 even.  Those latter are interchangeable.  I've done this in the ATR8000 on a couple of occasions when I needed to test with KNOWN-GOOD ram and all I had were 256kbit chips to be certain of.

 

Best,

 

jeff

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What about RAM?  If this were a doubler 1050 or some other drive conroller, I'd suspect the sram.
 
The ATR8000 uses DRAM, but say that one of your drams has a stuck bit smack dab in the area reserved for the disk controller?  You might try swapping for a known-good set of 4164's, or 41256 even.  Those latter are interchangeable.  I've done this in the ATR8000 on a couple of occasions when I needed to test with KNOWN-GOOD ram and all I had were 256kbit chips to be certain of.
 
Best,
 
jeff

Aha. I don’t have any 4164s. I popped them out and re-seated them. Maybe I will move them around. See what happens. Anyway I ordered a “new” set as well.

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When the FDC goes bad,  those 7416's might have went blooey too as they control the Drive Selects, Side Select and Motor On...

That is going to be my last resort. I am not relishing unsoldering those chips. I had a hard enough time with the caps. I really don’t want to have to get an unsoldering station. I know a pump will work but from all the videos I have watched they don’t work to well.

Later today I am going to swap around the dean chips and hit pin 37 of the 1797 with my logic probe see what it is doing.

My new chips won’t be here til Tuesday. Will keep you all informed of my progress.

Thanks again for all the help.

P.s. how many 7416s are there that have to be replaced?

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I would check pin 37 with a logic probe while going. Either that or data sep clock not being selected properly.
 
James

Checked pin 37. Stays low. Tried formatting and different things and it always stays low.

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1 hour ago, moonlight_mile said:


Checked pin 37. Stays low. Tried formatting and different things and it always stays low.

That pin should be low for DD and high for SD.  You checked it inline (not lifted)?  Is it high on a SD format?

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On 9/5/2020 at 8:24 AM, moonlight_mile said:


That is going to be my last resort. I am not relishing unsoldering those chips. I had a hard enough time with the caps. I really don’t want to have to get an unsoldering station. I know a pump will work but from all the videos I have watched they don’t work to well.

Later today I am going to swap around the dean chips and hit pin 37 of the 1797 with my logic probe see what it is doing.

My new chips won’t be here til Tuesday. Will keep you all informed of my progress.

Thanks again for all the help.

P.s. how many 7416s are there that have to be replaced?

Don't use 4116.  Use 4164 or 41256 and move the jumpers to configure the machine for 64k.  Why wouldn't you? 

 

Best,

 

Jeff

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That pin should be low for DD and high for SD.  You checked it inline (not lifted)?  Is it high on a SD format?

Ok. Went back down and played around.

Pin 37 isn’t active during boot up. It goes low when I do the first dir.

When I ainit or xinit in single density the probe does not light up.

When I go xinit in double density it lights up and stays lit. Never goes out until the device Naks and errors out.

The head moves a little during the dd format but not the way a normal format head movement.

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I ordered some 7416s and sockets just in case.

Dumb question, can you piggyback the 7416s like we used to do with ram chips to see if the soldered chip is defective? (Get the idea I am try to avoid unsoldering the chips huh? Lol).

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