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What drive do you have with your ATR8000?

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I am trying to get a floppy drive to work with my ATR8000 but have had no luck. I don't know if it's the two drives I have tried or the ATR8000 that isn't working. 

But they both turn on and spin when they are accessed but I have no formatted disks to try and write or read from. When I try and format it sounds like it's starting to format but it's not switching tracks like a regular 810 does. Eventually it times out and I get an error 173. 

 

If you have a floppy drive working with your ATR8000, what type is it .. exactly. 

 

Frank

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I remember BITD that the 360K and 1.2MB 5.25" drives had a resistor termination block.  It looks like a 14 pin DIP IC, but it is the resistor termination block.  If memory serves me correctly, the last drive on the chain needs to have that block installed.  The one upstream has to have it removed.  Also the old IBM PC "twist" in the 34 pin cable between drives is not needed. Again, if my memory is not failing, on a IBM cable, there are about 5 lines that flip in order on the cable between the two drives to differentiate drive A from B. 

 

I used both 360K DSDD and I used a 1.2MB HD drive.  I formatted the 1.2MB as a 8" 77 Track DSDD disk which yielded ~1MB after format. MyDOS thinks its a 8" floppy.

 

  minuszerodegrees.net

Edited by ACML
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3 hours ago, _The Doctor__ said:

how about pictures of your drives pcb areas so we can help with configuring your?

Here are pictures of the two drives I have. The first is the 360KB one. The second is the 1.2MB one.

I have a straight 34 pin cable. I was trying them one at a time. Selecting the drive with the jumpers seems to work fine. That's the only one where I know what it does. 

IMG_5358.jpg

IMG_5359.jpg

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make and models of the drives please, I can not read the silk screen on the second drives upper 2 locations. I guess they are ss3 and ss4?

there are more setting either hiding on the edges or under the shield

 

for the second drive until I get more info... you may with to move ss1 from 1 to 2

move the working drive jumper d2: to d3:

 

the reason being we know your dos accesses drive 2 and I'm speculating ss1 is drive # select.

 

if the working drive doesn't work as drive three, your DOS might need 3 and 4 turned on and DOS files re written...old Atari DOS etc... SPARTA and Later MyDos should not have such issues.

 

also the resistor network are not always a single dip chip, many times the are sip's  Pull back so we can see them plz

 

are the cables perfectly straight ribbons or is there a twist in a small group somewhere on the cable?

Edited by _The Doctor__

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Mine came with 2 Teac FD-55B-01-U mechs.  I have since swapped one of them out for a DSDD mech from my old PC-XT clone for better compatibility with other Atari drives.  Not sure of the model on that one.

 

As the Doctor says, straight through cabling, correct DS jumpering, and proper termination at both ends of the cable are critical to get these working.

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I haven't used mine in years, but I had a 360K 5.25" drive IIRC as well as a 720K 3.5" drive.

 

As mentioned here, termination is one point (last drive in chain should be terminated).  With some drives there is a jumper to enable this, in other drives there is a resistor pack  you would put in place or remove to do this.  I'm unsure about 3.5" drives as many don't have jumpers, and they don't have spots for resistor packs.... they either don't have it, or it is automatic ?  Hopefully someone knows the proper answer to that one.

 

Jumpers are important.  The ATR may work with a 'PC twist' floppy cable.... and if so, then all drives should be configured to the 2nd ID (1 or 2 depending on drive numbering of 0-3 or 1-4) and there should only be 2 I believe (one before and one after the twist).   Pretty sure mine was being used with non twist cabling, and the drives all need to be uniquely ID'd.  It may support 4 drives, I don't recall.

 

I used mine beyond single density with MyDOS at the time, but I believe any of the more modern DOSes should work fine (i.e. SpartaDOS).

 

Mine also has a Z-TEC 1000 in it which from what I understand is a SASI drive interface.  And I have a Xebec 1410 (# may not be correct, going by memory) bridge controller, that the prior owner once had connected to the ATR, and in turn to the Atari to have 20M (ST225) for his Atari BBS back in the day.

 

I was never able to determine if I had all the programs and process to low level format an MFM drive off of the bridge controller in order to get a HD up and running, and therefor never succeeded.  I used it for a floppy controller for higher capacity floppies and I dabbled with CP/M with it.

 

 

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5 hours ago, _The Doctor__ said:

make and models of the drives please, I can not read the silk screen on the second drives upper 2 locations. I guess they are ss3 and ss4?

there are more setting either hiding on the edges or under the shield

 

for the second drive until I get more info... you may with to move ss1 from 1 to 2

move the working drive jumper d2: to d3:

 

the reason being we know your dos accesses drive 2 and I'm speculating ss1 is drive # select.

 

if the working drive doesn't work as drive three, your DOS might need 3 and 4 turned on and DOS files re written...old Atari DOS etc... SPARTA and Later MyDos should not have such issues.

 

also the resistor network are not always a single dip chip, many times the are sip's  Pull back so we can see them plz

 

are the cables perfectly straight ribbons or is there a twist in a small group somewhere on the cable?

 

The first drive is a Fuji FDD 5445A0N 360KB. The cable is straight, no twists. I'm using MyDos 4.53. The problem seems to be that I can't set the density. When I use option P in MyDos and specify 2,D it ignores it and sets it as single density. I also wasn't sure what to put for the Step Rate in MyDos. 

 

Frank

IMG_5360.jpg

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JUMPER DESCRIPTION                    SETTING

D1         Drive selected as DRIVE 1  OFF

D2         Drive selected as DRIVE 2  ON

D3         Drive selected as DRIVE 3  OFF

D4         Drive selected as DRIVE 4  OFF

LD         The LED comes on when    ON

             the Drive Select signal is

             set to 1.

        If LI is also on the LED will come on only when the In Use signal is set to 1.

LI          The LED will come on when ON

             the In Use signal is set to 1.

         If LD is also ON the LED will come on only if the drive is selected

TM         Terminator                        ON (if last drive on ribbon)

                                                      OFF(if not last drive on ribbon)

Edited by _The Doctor__

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step rate  could be 3, 4, 5, 6, or more... I will have to search for a print out... somewhere....

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On 5/28/2020 at 10:42 AM, ACML said:

I remember BITD that the 360K and 1.2MB 5.25" drives had a resistor termination block.  It looks like a 14 pin DIP IC, but it is the resistor termination block.  If memory serves me correctly, the last drive on the chain needs to have that block installed.  The one upstream has to have it removed.  Also the old IBM PC "twist" in the 34 pin cable between drives is not needed. Again, if my memory is not failing, on a IBM cable, there are about 5 lines that flip in order on the cable between the two drives to differentiate drive A from B. 

 

I used both 360K DSDD and I used a 1.2MB HD drive.  I formatted the 1.2MB as a 8" 77 Track DSDD disk which yielded ~1MB after format. MyDOS thinks its a 8" floppy.

 

  minuszerodegrees.net

Trying to wrap my head around this.....

 

First, I'm presuming this is using DD media and not HD media. 

 

I'm trying to figure out how with 3 less tracks you have more space than QD 5.25" drives (80 track DD drives) which IIRC format to 720K (80 tracks, double density, 2 heads, 9 sec/track).

 

Back in my early PC days I used to make custom format disks under DOS to try to extract every last byte from a diskette.  At best you could stuff an extra 512 byte sector, and you could generally get 1-3 extra tracks depending on the drive and media.  So, if I'm calculating this correct, the QD (not over formatted) will be 720K.  Even with an extra 512byte sector jumps to 800K.

 

Looking up DEC's RX02 8" format, and doubling it (since RX02 was single sided) looks to make 77 tracks, 2 heads, DD, 26 s/track (256 byte sectors).  which is 1001K.  An equivalent 512 byte format would e the same numbers, but 13 s/track.  But on a 5.25" at 300oe (DD) I see that as adding 4 extra sectors per track.... and at smaller sectors more space is wasted (harder to pack more in).

 

So, what am I missing here.....

 

Is the 77 track format on DD 5.25" media using a 360RPM HD 1.2M PC drive on an ATR8000 simply able to overstuff that much data on a DD 5.25" floppy ?????  I don't recall ever being able to add that many 'extra' sectors in my days of playing with custom PC formatted floppies.

 

This should also mean if a DOS would allow to change the tracks... changing that 77 track to 80 track and packing the same punch per track would result in 1040K !  On DD media ? !

 

Pretty cool and one of these days I'll have to bust my ATR8000 back out and try it 🙂

 

 

Edited by cwilbar
addendum

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In order to get it to format as a 77 track DSDD, you have you use 1.2MB HD 5.25" floppies.

 

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Thats what I was missing.... I did some more digging, and the while the 8" is double density... the data rate is 500Kbps.  I had presume that all double density was 250Kbps....

 

Some more studying of http://www.retrotechnology.com/herbs_stuff/drive.html helped me clear that up.

 

I get it now :-).  I do gather that the 1.2M HD 5.25" drives (depending on manufacturer) support 300 and 360RPM operation and in replacing an 8" with a 5.25" HD unit you'd want 360RPM to match the 8".

Where when reading or writing (bad idea) 360RPM media with the HD drive you want to rotate at 300RPM with 250Kbps, or 360RPM with a 300Kbps data rate (which IBM did with the AT using only 360RPM for the HD 5.25" drives).

 

I missed that little data rate difference which completely explains everything (and the need for HD media to replace the 8" DD format with the 5.25" HD format).

 

Only question now is on an ATR8000 if you can get those 3 lost tracks back 🙂 when doing this 'trick'.

 

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Dug my drives out last night but forgot to make note of the models.   

 

From 1983 until about 2008 I used TEAC FD-50A single sided mechs.  Never did feel confident about as to how to change the the pressure pads.   Replaced the mechs with double sided Chinon FZ-502 drives (I think that the model) from a 1989 PC-XT clone (yes, 1989!).   I occasionally connect one or two 1.2 MB mechs.  I can't remember the make or model numbers.  Definitely dual speed units retained from my first PC, a PC-AT clone. 

 

These days I mostly just run the drives to see if they still work.  I try to do something to keep my interest at least for a few hours.   This time it was connecting the ATR8000 and using an ESP8266 with one of  the older fujinet test firmwares ("multilator-rev2-n32").  There aren't many SIO2whatever type devices that ATR8000 would play well with.   

 

I never managed to get the 1.2 MB drives to work in tandem with the 40 track drives. 

 

-SteveS

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