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Idea:External Atari ST drive transformed to 8-bit (XF551 internals)

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I guess the 8050 and 8040 jumper  has something to do with using the "internal" firmware or the firmware inside the eprom. I am not sure how that works, but I realize that when using the intel 8050 with "Atari" brand.  I can set the jumper in 8050 and the board kind of worked but it did not use the HyperX firmware (so I assumed that is the original firmware...!?!?). If I set the jumper to 8040, the HyperX firmware menu showed up at boot time. 

If I tried the same with generic i8050 the board did not work with the jumper in 8050 mode.

I am sure someone here, have a perfect understanding of this. 

BTW, my xf551 original from the beginning of the 90s did not include any (ep)rom , it only included i8050 atari branded and the wd1772 controller.

 

 

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There are two jumpers on the SF551 board.

 

The CPU jumper which pulls the pin 7 (EA) on the CPU either high for the Intel 8040 or low for Intel 8050 version.  The jumper is on the original XF551 boards, but is usually hard jumpered for the version of cpu that was installed at the time of manufacture.  Basically it's there to turn off the Intel 8050 internal 2k of ROM if that is the cpu you are using.   It should be set for the cpu you are using. 

 

The OS jumper simply selects which portion of the Eprom(high/low) you are currently using. 

 

Now depending on the version of firmware you have selected by the OS jumper, you could have interesting responses.  It's all dependent on the firmware and how it handles the high/low signal on pin 7.  When you consider that you are using a modified version of the original Atari firmware to get 3.5" floppy support there maybe some unintended consequences too.  I believe the HyperFX firmware is aware of the pin signal and may behave differently as well.  Someone can check me on it. 

Edited by Dropcheck
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I finally got both boards working but I don't know how or why.  I had one of the boards working Tuesday evening, turned everything off and the next day it wouldn't boot a drive. I reformatted disks, changed jumpers, changed out some chips and everything started working as it should. The only problem is now the only drive that would fit inside the case with the board has also stopped working correctly. It will not boot a disk. If I set it as drive 2, it will give a menu but it will not format a disk. It acts like it is trying to boot and just keeps going through the same cycle over and over.

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run a cleaner disk through the drive...

then try to read a directory off the drive (don't boot from the drive)

so boot from whatever then read disks, format them etc...

don't forget if you want them to boot with sparta to use the boot x32d.dos command on the disk... don't power off.

if it boots from the drive cool. do the same for the other drive.

 

now for the fun... shut power off to both drive and the computer

 

wait 5 minutes, turn on one drive and try to boot directly from it...

does it fail to boot? okay then press reset real fast about 5 times on the Atari and see if the drive doesn't wake up and boot...

do the same with the other drive...

 

if they both decide to boot, this is normal as far as 3.5 inch drives are concerned...

You can run the XF boot patch tools I uploaded who knows how long ago... that will make the density switch on boot by sending a reset to the XF. This is by design, for a 5.25 inch drive it prevents the XF from failing to boot and load certain copy protected disks... an XF aware DOS will switch the density on purpose. They just forgot about updating other DOS variants to do that in their bootstraps. Didn't exactly share that info with the world either.

 

You can avoid all that with other firmware versions. They have the density switching modified. I can't speak to all the different flavors of firmware out there. Some did a better job of loading protected games than others, some switched density like the old XF some switched super quick or on any error.... so just be aware.

Edited by _The Doctor__

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This os one project that I regret having become involved with.  I believe that the drives or the boards or the firmware are affected by atmospheric pressure or something. I can get a system working; booting, reading, and writing, turn everything off and an hour later the drive might not do anything correctly. The standard drives are less quirky but it order to use them, either the case or the drive will require some major modifications.

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I have decided that the only way to make something good come out of this is to cut a rectangular opening for a standard 3.5 floppy in the front of the case of those drives with the slanted openings (unless you happen to have a drive that is working). I have no slanty drives that will boot or even read a disk. I did this to one case. Now I need to raise the drive up 1/4 inch above the present supports. I am thinking small wooden strips or some small vinyl washers. Then find a way to secure the board.  I would also like to get a 3D printed rectangular rear plate cut specifically for the connectors of the new boards. 

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Finally finished my prototype. It involved some major work on the inside of the case and I would not have been able to accomplish it without some woodworking experience and tools. Now that I have done one, the next one should be easier, quicker and better. I posted an album but I don't know how to link it to this topic.

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32 minutes ago, hueyjones70 said:

I posted an album but I don't know how to link it to this topic.

I can't find it.

 

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3 hours ago, hueyjones70 said:

Finally finished my prototype. It involved some major work on the inside of the case and I would not have been able to accomplish it without some woodworking experience and tools. Now that I have done one, the next one should be easier, quicker and better. I posted an album but I don't know how to link it to this topic.

there are no images or albums in your profile, so you haven't uploaded them yet... nothing to link to...

if you added such things to a post you have to use the plus sign on the right hand side to put it in the post, otherwise it is an attachment no one sees....

 

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18 hours ago, hueyjones70 said:

Finally finished my prototype. It involved some major work on the inside of the case and I would not have been able to accomplish it without some woodworking experience and tools. Now that I have done one, the next one should be easier, quicker and better. I posted an album but I don't know how to link it to this topic.

I am happy you make it happen with a drive which was NOT compatible with this PCB. I am also trying to do something similar with a sf354 (eject button in the middle) which is totally different inside with respect to the sf314 (with 7 screws) that is the drive you really need for this project.

But since we like challenges, I am trying to get a nice looking XE styled 8bit compatible 3.5 floppy drive, starting with this crappy sf354 drive and using a slim 3.5 mechanics.

 

 

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Will the 1770 IC work with this particular setup and/or the mixed parts board that was designed for the XF551?  I ask because several of the XF551s that I have were equipped with that IC on the original PCB and they are much cheaper.

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My experiments indicated that you could use the WD1770PH with a 5.25" drive, but when I tried a 3.5" drive I had to use the WD1772PH.  Conversely you could use a 8.0MHz OSC with the 3.5" drive, but you had to use a 8.333MHz or equivalent OSC circuit with the 5.25".  I have not tested with differing OSs, so there is the possibility that that could also be a factor.  

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I just realized that I have been using .1uf 50V multi layer capacitors where I should have been using .1uf 100V multi layer capacitors.  I have done this on three boards and they are performing well.  Does anyone know what effect will this have on the long term life of the board and should I replace them all?

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I will attempt to attach some pictures of my first successful attempt.  I had do some modifications to the case and I also used some wood strips as spacers.  I used the wood because I needed to elevate the drive by 1/4 of an inch and I have the carpentry tools to get spacing pretty exact.  I will use a file to smooth out the opening for the drive selector.  I wish I hadn't used a case that was chipped.  I did it because I didn't know if I would be able to make everything work and I didn't want to ruin a good case.

SF354a.thumb.jpg.a3468679c9e65e7a147f4c1730453008.jpgSF354b.thumb.jpg.c87cc760cedc0dda04b7093ad3fb0a5b.jpgSF354c.thumb.jpg.aea7bfcac479a6b2dc0825437e246462.jpgSF354d.thumb.jpg.ebd710a62b7c0c8162e33dc64e5a5ec6.jpg

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I am having mixed success with assembling a working PCB. I don't know if it is due to salvaged parts, or poor soldering skills but my success rate is about 50%.

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Is there anyone who makes an SIO cable for this? I like it very much, but I can't see well enough anymore to solder DIN connectors.

 

I have always wanted a drive like this!

 

That is a beautiful drive.

 

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21 hours ago, Kyle22 said:

Is there anyone who makes an SIO cable for this? I like it very much, but I can't see well enough anymore to solder DIN connectors.

 

I have always wanted a drive like this!

 

That is a beautiful drive.

 

I have made 4 or 5 SIO cables.  I have to use a lighted magnifying glass to do most of my soldering.  I wish I could afford one of those magnifying glasses like dentists use.

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I now converted a SF314 drive to 8-Bit use.  This was extremely simple once I was finally able to put together a working PCB. Just insert the PCB in the case and connect the cables. Works nicely.  I have considered having a new model label made and label it as an XF315A or XF315M, but I don't know if that would be legal if I decided to sell one. 

SF314 A.jpg

SF314 B.jpg

SF314 C.jpg

SF314 D.jpg

SF314 E.jpg

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Who cares about legal? Just DO it. Atari has never gone after me for using Harry and Optima fonts on signs I have on the windows of my store.\

All they will do is send a cease and desist to you.

Just do it (tm).

 

:)

 

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