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

[ijor]

The XF551 can read PC disks (as in: formatted on a PC for use with Windows). Will the XF314 be able to do so too? Or maybe even write files to them?

 

The SF314 drive mechanism is fully compatible with PC 3.5 DD disks. As a matter of fact, you can say it is the equivalent as the XF551 drive mechanism but for 3.5 disks. In both cases you need custom firmware and software, of course. But actually the 314 would be more compatible with PCs. This is because you don't need to overclock the FDC as the XF551 needs for backwards compatibility. This means that you would use the same bitrate as a PC.

[Mathy]

Hello guys

 

Somebody wrote software to read 5.25" PC floppies years ago. IIRC it was Bob Puff. The software was only capable of reading the disks, not write to them, because the XF551 couldn't support that. Not sure if it worked on the stock XF551, but I guess it did. (Correct me if I'm wrong)

 

Sincerely

 

Mathy

 

Edit: you need one of the XF upgrades from CSS: "The other feature of this upgrade is the IBM/ST Transfer Utility. This program reads 360kB 5.25" disks formatted on Atari ST and IBM computers."

Edited January 4, 2019 by Mathy

[Lynxpro]

Adding this here because there doesn't really seem to be a better thread for it.

 

The XF351 was sold in tiny numbers - in Ireland. I can remember seeing them in Peat's of Parnell Street (the main Atari retailers in the Dublin area) c.1987.

 

One was attached to a 130XE for demonstration, and there were a few boxed units for sale out on the floor. This was around the time that I was getting into the ST, and was interested in it right up to the point where I discovered that despite using the same disk media, filesystem compatibility between the ST and 8-bit was still nonexistent. At that point, I just stuck with whatever the package was that copied data over the joystick port of the 8-bit to the ST.

 

What sorcery is this you speak of? There was a way to transfer data from A8 to ST - and vice versa - via the joystick ports? If that's the case, I'm surprised nobody did that at the Atari user's group I belonged to back in the day...which was both A8 and ST.

[+CyranoJ]

TariTalk

 

I bought one from Page 6 many years ago. Still have it somewhere.

[+x=usr(1536)]

TariTalk

 

I bought one from Page 6 many years ago. Still have it somewhere.

 

Yep, that's the one I had. Worked well for what it was, though I recall it was a bit on the slow side.

 

Something in my mind is suggesting that there may have been a DIY version out earlier, but I could be confusing that with the speech synth (also connected to the joystick ports) that I built from an article in Atari User.

[+slx]

 

Actually it's the other way around.....which always seemed weird to me.

The 14 stands for 1.44MB methinks (although the 354 has less than 520K).

There seem to have been few enough 354s to make single-sided discs obsolete rather soon, other than on the 8-bit were SD remained the norm for commercial releases.

[atarian1]

The 14 stands for 1.44MB methinks (although the 354 has less than 520K).

There seem to have been few enough 354s to make single-sided discs obsolete rather soon, other than on the 8-bit were SD remained the norm for commercial releases.

 

SF314 = double sided floppy disk can hold up to 1MB unformatted. A formatted double-sided floppy disk holds 726K on the ST.

SF354 = single sided floppy disk can hold up to 500K unformatted. A formatted single-sided floppy disk hols 354K on the ST.

[+slx]

 

SF314 = double sided floppy disk can hold up to 1MB unformatted. A formatted double-sided floppy disk holds 726K.

Right, 1.44 only came quite some time later, I remember buying a very expensive Atari-shaped 1.44 drive for my TT to avoid butchering the case.

 

That ‚unformatted capacity‘ while techically correct was mostly a boon to marketing....

 

 

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[ijor]

SF314 = double sided floppy disk can hold up to 1MB unformatted. A formatted double-sided floppy disk holds 726K on the ST.

SF354 = single sided floppy disk can hold up to 500K unformatted. A formatted single-sided floppy disk hols 354K on the ST.

 

 

Where do you get those numbers for the formatted capacity? The formatted capacity is 720K and 360K respectively. That refers to the total number of bytes available, including for metadata (directory, VTOC, etc). If you want to count sectors available for actual files only, it would even be less, but I still don't see how you get the 354K figure for single sided unless you mean approximately. And certainly 726K can't be right, guess that is a typo.

Edited January 5, 2019 by ijor

[+Nezgar]

Maybe 354K accounts for 6K taken by directory/vtoc from 360K... I agree 726K doesn't make sense.

 

Single sided: 9 sectors x 80 tracks x 512 bytes / 1024 = 360KB

Double sided: 18 sectors x 80 tracks x 512 bytes / 1024 = 720KB

 

Of course on the ST lots of people used 10 sectors per track, and 81 or 82 tracks for 820KB for example.

[atarian1]

 

 

Where do you get those numbers for the formatted capacity? The formatted capacity is 720K and 360K respectively. That refers to the total number of bytes available, including for metadata (directory, VTOC, etc). If you want to count sectors available for actual files only, it would even be less, but I still don't see how you get the 354K figure for single sided unless you mean approximately. And certainly 726K can't be right, guess that is a typo.

 

That's what the GEM desktop says after formatting a floppy disk. A dialog box says "This disk has 726016 bytes available to user." after a double sided disk is formatted. The dialog box says "This disk has 357376 bytes available to user." after a single sided disk is formatted. (Yes, it's 357K, not 354K. My bad.)

 

I am guessing people just round off to 360K/720K to make it easier to remember and understand.

Edited January 6, 2019 by atarian1

[ijor]

That's what the GEM desktop says after formatting a floppy disk. A dialog box says "This disk has 726016 bytes available to user." after a double sided disk is formatted. The dialog box says "This disk has 357376 bytes available to user." after a single sided disk is formatted. (Yes, it's 357K, not 354K. My bad.)

 

Ah, but that's not what we mean by "K". The "K" on 360K and 720K means KibiBytes, not KiloBytes. See Wikipedia for the difference. But many of us still use the prefix "Kilo" because that's the one that was used then. Regarding floppies I think almost everybody use "K" in that sense.

 

I am guessing people just round off to 360K/720K to make it easier to remember and understand.

No. That's the exact value (again, in KibiBytes) for the total formatted capacity, including metadata (VTOC, FAT, etc). What you see at the GEM desktop info is the net capacity (in bytes) for files themselves.

[Tezz]

 

The proto board files went to the board house a couple of days ago. Should have them arrive in a week or so.

 

How are things progressing with this?

 

Although this is being designed to fit into an SF314 case with much of the original parts retained I'm still hoping that it will go on further to something we can build from scratch in a custom 3D printed case. I'm considering getting the Kryoflux mini 1050 case printed just to see how it could possibly look next to the XL. I've got a bunch of 3.5" DSDD disks and an NEC 720k drive mech aside for this.

[manterola]

Things are going great. Dropcheck will provide more news and details. The PCB is meant to be installed in the SF314 case and it reuses the On/Off switch, Din5 male power connector, inductors and power and data floppy half cables, but might be used without a case (or with another case) and those parts be sourced elsewhere.

I'd also like to have an XL styled 3.5 floppy drive... someday...

[Dropcheck]

 

How are things progressing with this?

 

Although this is being designed to fit into an SF314 case with much of the original parts retained I'm still hoping that it will go on further to something we can build from scratch in a custom 3D printed case. I'm considering getting the Kryoflux mini 1050 case printed just to see how it could possibly look next to the XL. I've got a bunch of 3.5" DSDD disks and an NEC 720k drive mech aside for this.

 

 

Current status is testing phase. I have used some parts from the original board assuming that the user is using the original SF314 power supply and will be using custom SIO pigtail to SDD-130J DIN13 connectors on board. At this time I am also assuming that the original SF314 floppy drive with the single industry standard IDE connector will be used as well.

 

These parts are planned to be salvaged from the original SF314 control board.

 

DIN5 Male Power Connector

Power Switch

L1 and L2 AC Common Mode Chokes

 

All other parts at this time are still in flux or will come from an XF551 board. I hope to only have a single small case modification to allow drive ID selection on the rear.

 

Stay tuned. Once I have verified a working board I'll post here.

[Tezz]

Sounds great. I'll look out for your updates.

[Mathy]

Hello Lenore

 

On most drives for the Atari 8 bit computer, we can select one of four drive IDs. Two pins are used on the switch. But with a slightly bigger, three pin switch, we would be able to select one of eight drive IDs. "Way back when" almost nobody had a third drive, let alone a fourth. But nowadays, quite a lot of us have more than four drives (real or virtual, old and new design). That's when being able to turn in drive into one of eight drive numbers comes in very handy.

 

Sincerely

 

Mathy

[+kheller2]

Hello Lenore

 

On most drives for the Atari 8 bit computer, we can select one of four drive IDs. Two pins are used on the switch. But with a slightly bigger, three pin switch, we would be able to select one of eight drive IDs. "Way back when" almost nobody had a third drive, let alone a fourth. But nowadays, quite a lot of us have more than four drives (real or virtual, old and new design). That's when being able to turn in drive into one of eight drive numbers comes in very handy.

 

Sincerely

 

Mathy

 

I like the old dial selectors for SCSI 0-7

[+Nezgar]

Well... SpartaDOS X supports 15 Drives... Could have a 16 position BCD rotary switch for any of the 15 drives.

 

So.. you know, you could demonstrate 15 of these drives all working at once?

[_The Doctor__]

well actually more

15 standard

plus how many pcl drives?

and if someone wished that could change the driver and assign 15 drives in addition with another identifier for the ide drives etc etc..

Sparta is cool that way...

 

and we can cheat by swapping partitions in and out or whole devices or lun....

a good deal is possible...

Edited January 25, 2019 by _The Doctor__

[+tf_hh]

On most drives for the Atari 8 bit computer, we can select one of four drive IDs. Two pins are used on the switch. But with a slightly bigger, three pin switch, we would be able to select one of eight drive IDs. "Way back when" almost nobody had a third drive, let alone a fourth. But nowadays, quite a lot of us have more than four drives (real or virtual, old and new design). That's when being able to turn in drive into one of eight drive numbers comes in very handy.

 

Cool - you´re offering to code a new or patched XF551 firmware or better Hyper-XF? Then please go ahead, then I´m pretty sure that Dropcheck will include this in the layout - that´s easy, as three I/O pins at the 8040/8050 are unused. Otherwise such comments are nice, but it´s always the same problem: If nobody wants to code the software/firmware, then the hardware is useless.

[+tf_hh]

I like the old dial selectors for SCSI 0-7

 

Me too

 

But these selectors are very hard to get today...

[Dropcheck]

Hello Lenore

 

On most drives for the Atari 8 bit computer, we can select one of four drive IDs. Two pins are used on the switch. But with a slightly bigger, three pin switch, we would be able to select one of eight drive IDs. "Way back when" almost nobody had a third drive, let alone a fourth. But nowadays, quite a lot of us have more than four drives (real or virtual, old and new design). That's when being able to turn in drive into one of eight drive numbers comes in very handy.

 

Sincerely

 

Mathy

 

That is an option, but it involves a serious limitation. You have to have firmware that will support the 3-position DIP switch or modify existing firmware. And take another pin on the cpu which maybe used for another person's modification.

 

I was looking at that some time ago and did find this info on Gramblicka's site. You might have to run it through google translator. It doesn't really change the physical ID switch, just renumbers the existing four to a higher number. Apparently there is already modified firmware that can be burned and dropped in the eprom socket of an existing XF551. No physical modification needed.

[Mathy]

Hello Jürgen

 

 

Cool - you´re offering to code a new or patched XF551 firmware or better Hyper-XF? Then please go ahead, then I´m pretty sure that Dropcheck will include this in the layout - that´s easy, as three I/O pins at the 8040/8050 are unused. Otherwise such comments are nice, but it´s always the same problem: If nobody wants to code the software/firmware, then the hardware is useless.

 

I know my limitations. I don't have the ability to develop either software or hardware. What I do is come up with ideas. If you hardware guys and girls can't turn them into reality, that's fine, not what I hope for, but fine. But I might come up with an idea you guys and girls didn't think of. And maybe this idea makes the hardware and software you guys and girls develop better, easier to use or more versatile. Making you guys and girls shine even more. I would love to have the abilities you guys and girls have, but I don't. That's why I try to help you guys and girls to make your products better. Better for the developer and better for the user. That benefits us all.

 

BTW an option that exists in hardware but lacks the software to support it has the chance to be supported later on. Options that aren't supported in hardware, will never be supported in software.

 

Sincerely

 

Mathy

[BillC]

A simpler method would be to use different firmware in some drives configured to use IDs 5 to 8. This could also be done with multiple firmware in a larger switched EPROM to allow stock drive IDs when needed.

 

This type of firmware isn't a new idea, BITD ICD offered a version of the US Doubler ROM that was configured for drives 5 to 8.