cwilbar

Like polishing a turd. Though, I may try my hand at making a set of plastics from cutting up this and another bad set of 810 shells. Though I'd still be missing the front plastic bezel. Right now that dirty old plastic serves to protect the guts and thats about it 🙂 I was quite pleased to get it working, and that it works well. As I really only bought it for parts. Now I'll probably watch for another set of plastics, or someone with a dead drive for sale.

An 810 parts drive. Cosmetically junk, but got her spinning. Needed a replacement ROM (used a 2716 and wrote about how to use a 2716 on one of these in another thread). Boots games/etc fine. Looks like sin.... but hoping to find another 810 shell someday. At ~$30 shipped, I'm not complaining as I was factoring on it for parts to begin with. Also bought a lot of over 200 disks along with some disk filers. one 3.5" disk box broke in transit, as did one of the 5.25" boxes, but I still got a good 3.5" disk filer, and a good 5.25" disk filer, and a bunch of 720K DD 3.5s (that was most of what was in the lot). Some interesting originals (non Atari) too. There are more, but those are a couple of the recent Atari related things.

Wow... never heard of Roctec. I think the hardest thing is going to be coming up with something that applies the correct pressure. Too little and you could have read/write problems, too much, and it will not be kind to the media (or the drive motor and belt). If you can't find it, if you can locate a 1050 Tandon mech, my guess is that could be transplanted until a day where you can find or make the appropriate part. I'd say if you can determine the tension on a Tandon mech, that would be probably a safe value for the Roctec.... but you'll need to find a way to measure the pressure and modify something until it is dialed in.

Yeah, shipping is a mess, but I've not seen a required shift to the more expensive carriers from international locations in a few other things our family has received from international shipping. I'm sure it varies from location to location. Regardless, it might still be worthwhile to figure out some sort of group buy for USA recipients.

I believe the drive is essentially an Indus GT.... ??? If so, then it may use the Tandon mech just like the Indus GT does. The same Tandon mech was used in Atari 1050 drives (some 1050s used World Storage mechs... parts for that mech would be different). So, you can buy the parts for a 1050 (Tandon mech version) from an Atari parts vendor (like Best Electronics, B&C Computervisions, etc). If you haven't opened your drive yet, you should be able to locate the vendor of the floppy drive mechanism. If you aren't sure, post a photo (or photos) of the mechanism here for identification. LDW did not make their own floppy mechs.

Thats cool. From a flux detection perspective, I think the only difference between QD and HD drives would be that QD drives will be running at 300RPM (vs 360RPM). @JimDrew thanks for a terrific product. I had a learning curve, and ran into two drive issues (a Toshiba 360K which worked great but went flaky and became unreliable, and the FD-54B TEAC which seems to be writing at a drifting speed/bit rate/etc...). I will plan to try that TEAC on another power supply in case it is a power hungry drive that is sapping the old power supply in the Andatco enclsoure.... but I think it is most likely the drive.

I've had a bit of a learning curve and a bit of bad luck with a couple of old used drives... but I think it is a terrific device. Glad I bought one. I'm probably going to get a second one so I can support 48tpi and 96tpi 5.25" and 1.44M 3.5. It only supports two drives, so I could put 2 on one, and one on the other, and at that same time it serves as a spare in case one has an accident, gets fried, eaten by the dog 🙂 , etc.... It has no problems reading/writing A8 disks. I archived what I thought was my entire originals collection (only to find about 20-30 more originals I forgot about). I am using a 48tpi drive. Primarily as once everything is verified good (I use Altirra to test), I will be writing them all back out to new diskettes so when I do want to run an original program in an original drive, I won't be spinning the actualy originals anymore. I'd say the two most popular today are the Supercard Pro and the Kryoflux. While I don't have any Kryoflux experience, I selected the Supercard Pro, and other than some hits and misses with a couple of drives (one which started out find and went bad, and another that turns out to have some unusual behavior in writing (something unhappy after many years of life I guess).... I don't regret the purchase at all. If you do opt with any of these solutions but use a 96TPI drive (1.2M in the PC world (though outside the PC world there was QD which is 80 tracks at double density)), I'd recommend bulk erasing any diskette before you write it out. This isn't from personal experience as it has to do with the width of the head and the written track. Best to start with a truly blank disk (no data at all).

I don't have my ATR8000 setup anymore. I don't recall what 5.25" drive I used with it.... I mainly used a 3.5" 720K drive with it in a converted Wang external floppy enclosure (the box originally contained a scsi-floppy bridge board and a 5.25" drive. I stripped out the bridge board, scsi connectors/cabling, tne 5.25" drive, and put the 3.5" with an adapter frame and ran the floppy cabling out the rear and plugged it into the ATR. One of these days I'll have to get it back out again, and see if I can take another shot at getting the Z-Tec 1000 in it working (SASI interface for Z80 CP/M, possibly specifically only made for the ATR, but probably would work in many Z80 CP/M machines). I have a Xetec bridge controller (SASI<>MFM), but the thing that stopped me, was I was never able to figure out how to low level format the MFM drive.

I wouldn't concern myself with reads using a 96TPI drive too much.... but much prefer to write 48tpi disks using 48tpi drives. I would imagine that there is no choice to do this when half tracks are involved (C64, Apple).... as you can't half track a 48tpi drive (correct ?). In which case, I'd do a bulk erase and then a write with a 96tpi drive. Interesting question (not related to my 'lazy' FD-54B).... can QD drives be used with SCP ? Or will assumptions be made that a 96TPI drive is a 1.2M drive ? (I think I have 4 different 96TPI QD drives (including an MPI 'big door' style drive like in the 810). Thanks Jim ! -- Curt

As already mentioned, USD will add true double density support to the 1050, but it will not make it dual sided. The XF551 is double sided as well as double density.

I do not believe I had done the speed test, or if I did it was a quick spot check, and might have been fine at the time of testing. On the non flat waveforms, were they present in both the pana and fd54 files. While the FD did the writing, the 2 files represent an image taken with the FD54 and one taken with the JU465. If the speed wavering happens in read and write, I'd suspect it would be worse in the fd54 read (as there could be variance from read and from write) vs the JU465 read which would only detect the write variances. The enclosure the drive is in is an old Andatco box meant for 2 5.25" HH or 1 5.25" FH SCSI drive(s). It is the same enclosure that is now powering the JU465. I suppose the 12V could be noisy. I could always try it on another supply. If that doesn't change anything, then something is up with the motor control. There are a number of Nichicon caps on the motor control PCB. maybe they aren't up to snutff anymore ?

XF551 drives show up periodically on eBay. They come with sticker shock however. They are also prone to certain problems related to the power jack, power switch, regulators, etc. Atari must have decided to use ape spit to hold the copper foil onto the PCB.... as it doesn't work worth shit :-). Very sensitive PCBs... The cheaper ones will be untested drives (most of what is up on eBay are untested (or at least claim to be untested)). However, you'll want to have some basic soldering and troubleshooting skills. I may have one extra working drive available, but its mighty hard to part with XF551s :-). If your 1050 is stock and you have enough electronic skills, you should think about the US Doubler upgrade. It consists of a replacement ROM and you have to make a piggyback of a pair of 6810 RAM chips (as RAM needs to be doubled for double denstity operation). I have a number of 1050s to finish going through and repairing, and think I may update some of them to US Doubler before 're-homing' them to new owners.

Was going to preorder this.... but I'm having to reconsider for the time being, as even $41.10 USD for shipping is too much IMNSHO. Might wait, maybe once it is shipping we can get a group by to the USA to bring that shipping cost down to something more 'real' ? If nobody has already considered this, I would be willing to volunteer, though I'd have to figure out how we would go about it, as I couldn't up front all the $$$. -- Curt

So for anyone interested, here are 2 index reads of a media test write. I hit ignore on every error of the media test process. The write was done with a TEAC FD-54B. I've attached 2 index reads here, one read back with the FD-54B, and one read back with my Panasonic JU-465 (If I recall the model correctly). If useful at all, I could do a media test on the Panasonic and do a read with the FD-54B. I'll e-mail these to Jim as requested. media_fail_read_with_pana.scp media_fail_read_with_54b.scp

Thanks @JimDrew ! Over the next couple of days I'll hook that mechanism back up and do this. As I recall looking in the analyzer, there is a 'spike' of out of position 'bits' on the graph. Sort of like the start of track, end of track, or something with an overlap. The errors are random in occurrence .... never happening on the same tracks during repeat testing. When I switched to my Panasonic 360K mechanism, I had no issues media testing. I did read and write floppies with the TEAC drive that would not run a successful media test. That doesn't mean every read or write would be dependable however. Thanks Jim.... I'll do that test and send you an index read of the disk for you to confirm.

No problem. I left off the assumed information of both PCB boards being removed from the PC Tandon TM-100. The large one on the top, and the smaller one at the back.

OK.... here we go 🙂 (Note: I'm not sure if I've got pin #s correct (LtoR/RtoL) on these connectors, but the resulting instructions will work regardless. Connector 12 is the stepper (5 pin connector): PC: White, Green, Brown, Red, Black Atari: White, Red, Green, Brown, Black Connector 21 is the motor (5 pin on Atari, 4 pin on PC) PC: Yellow, Green, Red, Blue Atari: Yellow, Green, Blue, Red, N/C Head connector 9 is the head (head 1 on the PC drive) PC: Shield, Black, Blue and Yellow, White, Red Atari: White, Black ,Yellow, Shield, Red Connector 8 is write protect: on the PC this is a 4 pin connector, on the Atari, a 5 pin connector To use a TM100 in a Tandon Atari 810: Connector 12 (stepper): Remove the Green, Brown, and Red wires, place Red where the Green wire was located, place the Green wire where the Brown was located, and place the Brown wire where the Red was located (follow the Atari color map from the tables above) Connector 21 (motor): Swap the Red and Blue wires when plugging the connector into the Atari, leave pin 5 unconnected (leftmost pin when looking at the pins from above with the front of the drive towards you) Head connector 9 (head 0): remove the shield (bare wire), and white wires and swap them Connector 8 (write protect switch): no change, plug the 4 pin connector onto the 5 pin header on the 810 sideboard with the two wires connecting to the 2 bottom pins (leaving the top pin unconnected to anything) Connectors 9, 10, 11 (index LED, index sensor, track 0 sensor): leave unconnected, these are not used on the Atari 810 I left these dangling but they can be cut off, the sensors removed, etc if so desired. Head connector 10: leave unconnected, the 810 doesn't support 2 yeads. If you so desire and can get the parts (i.e. B&C, Best Electronics, etc) you can remove the upper head and replace it with rabbit hair pad, arm, spring, and 'spring bracket'. If you do not swap the red and blue wires on the motor connector (#21), the disk will spin backwards ! I have no idea what will happen if you get the stepper wires wrong.... either no stepping, or erratic stepping, buzzing stepper motor, possibly damaged 810 electronics ?) I would be afraid of damaging the head or electronics if the head wiring was wrong, though the most likely outcome is it wouldn't read or write anything. If incorrect, you could probably erase a disk you attempt to boot (or scramble its data). I have attached pictures of the connections on the swapped drive for further aid to the explanations above.

I'll see if I still have that drive by the bench. If I do, I'll open it up and see if I can document it. If not, I've got another Tandon TM100 that is destined for an IBM 5150, and I can look at that and a 810 Tandon and re-determine the wiring If you have a 810 Tandon mech to compare to, it is easy to determine the changes. If you don't have one to compare to...... thats where things get a bit harder.

Since the speed was controlled on a board removed from the PC TM100, and controlled by the board in the 810, if the speed is set correctly in the 810, when the PC TM100 is installed, it will spin at the 288RPM, not the 300RPM (as the PCB that controlled motor speed in a PC has been removed from the PC TM100). I dropped one right in to replace one that the head crapped out on. The PC donor drive was a parts drive that I received with the top head ripped off. Hung onto it for years.... and it finally came in handy 🙂

I fell for the bait 🙂

I wouldn't.... and don't see the point anyway.... What I've had to clean off of diskettes would not be water soluble (as in rinse off). In addition, if in the jacket, the jacket is going to prevent the water from rinsing anything off.... and the cleaning layer will absorb water, and make drying difficult and long (with the possibility of the media sticking to the inner layer as it dries. I can clean a 5.25" floppy pretty fast with a paper towl or cloth with alcohol. I 'pinch' the media through the window, and rotate the media... Once 'cleaned', I then continue to spin the media and blow on the media to dry the alcohol until I no longer see any liquid alcohol. I have not come up with a process for 3.5s yet.

In addition to Baking, I've heard that people have had success with reel to reel sticky tables using NuFinish (if I'm remember correctly.... the automotive product). Never heard of anyone doing it to diskettes though.

I put a Best mylar in a 1200XL I have. It is a well made part. It works as advertised.... however, as it does away with the 'intermediate' layer the contact points are very close together, and it doesn't take much of a press to activate. As I don't do a lot of typing on an Atari, it isn't that big of a deal, but I can type pretty fast... and when I try to on this 'upgraded' keyboard mylar, I too often an making the next contact before the last one is released. I feel that the additional 'closeness' of the contact surfaces exacerbates this more than a stock 1200XL keyboard mylar setup. I did save my old Mylar, and for 'fun' was thinking of fixing it to better compare. What conductive paint do people use to fix these ?

Success ! I lifted 18, 20, 21. Connected pin 20 (lifted) to pin 12 (not lifted) Connected pin 18 to pin 5 of Z102 (pin 2 of Z103 would work just as well). re-inserted the data separator board, installed it into the 810, and up and running ! So, if anyone runs into a bad masked ROM on their 810, this method of using a 2716 will work.

Looking further, the Data sheet indicates Vpp at 5V is READ mode. So, not sure if that needs to be tied to +5V, or if it can be left floating ??? Also, looks like the 2316 MASK ROM should have a tACC of 450 and since the enables and address should be driven in parallel (all via the address bus), then as long as the replacement is within that window we should be good. Looking at the 2716 data sheet (for 2716, not 2716-1 or 2716-2 which are faster parts), tCE is 450, so using tCE is match. tOE is much faster, so if more speed was needed, the answer would probably be to tie /CE low, and use /OE for 'chip selection' which allows for faster response.