PC floppy adaptor for Amiga

[Stedy]

Hi,

I've just returned from the workshop after a testing session, this time with a new adaptor board. This board allows you to plug a PC floppy drive into the Amiga with no modifications what so ever, to the drive.

I used a standard PC FDD cable, it is important that it does not have the twist in it that swaps A/B on the PC, unless you plug this adaptor into the untwisted part. My cable only had 1 connector and a twist, which I removed.

Whilst it works with 1.44 MB HD drives, when used with the Amiga they only work as 880K SD drives.

A few pictures of the prototype.

Top side view of the PCB.




Underside of PCB,
I built the PCB 4 months ago but only got around to testing it today.


Connections to the PCB

The lower cable comes from the Amiga, the upper cable goes to the PC FDD. Power comes from an ATX PSU
3.5" power connector.

Connected to a test drive


Finally, testing the drive by loading up Speedball 2



I tested the adaptor with 3 different drives, 1 was the Epson SMD-300 shown, the other two were brands I had never heard off.

All worked fine.

Testing comprised
* Booting Workbench 2.0
* Playing Speedball 2
* Playing F29 retaliator
* Spaceballs 9 fingers demo
* State of the Art Demo
* Copying and formatting of disks using D-Copy 3.1 and Workbench.

My next step is a few tweaks to the PCB then maybe make a few?

Who would be interested in an adaptor PCB?
Like my ATX adaptors, I need interest for about 25 units to make it viable and reasonably priced.

Any features you would like added to the PCB?

My current thoughts are

1) Jumper to counter act PC FDD cables with the twist (drive select crossover) in.
2) Additional 3.5" power connector or a flying lead to the new FDD, ideal for systems running from the stock PSU.
3) Bigger mounting holes for either sticky feet or another fixing
4) Fitting 34 way IDC plugs with polarity cut outs so that you can not insert the cables the wrong way around.

The schematics need a quick tidy up then I will put them online.

Ian

[keropi]

[tonyyeb]

Great stuff!

When will you be ready to take orders? Got a rough idea of cost?

Cheers!

[reanimator]

i'd be interested in one of these
thanks

[alexh]

Anything you can do with the form factor? Is it not possible to have it clip directly to the floppy disk drive or directly to the floppy disk connector on the motherboard so that you only need one cable? Similar to the ACard adapter for IDE->SCSI? If you could make it double sided in this style of pass through PCB (similar form factor to the back of the floppy disk drive) that would be great!

Most desktop Amiga's only have one floppy disk drive power connector. If they plug it into this board what will they plug into their floppy drive? Perhaps you could have a built in power cable splitter? Easiest way would be to soldering some short wires (with hot glue to fix them) directly to the PCB and have a floppy disk power at the other end? (I think this is thought 2?)

A silk screen on the PCB with pin 1 on all connectors.


How does it work? It doesn't look that complicated. A single Quad input NAND buffer!?

Does it work with original disks with copy protection? I am sure that someone on this board knows which games were the worst behaved. (i.e. the best to test with)

[Merlin]

Definitely put me down for one please, Stedy....

[billy]

Count me in for one as well Stedy.

[Eclipse]

Originally Posted by alexh

Anything you can do with the form factor? Is it not possible to have it clip directly to the floppy disk drive or directly to the floppy disk connector on the motherboard so that you only need one cable? Similar to the ACard adapter for IDE->SCSI? If you could make it double sided in this style of pass through PCB (similar form factor to the back of the floppy disk drive) that would be great!

Most desktop Amiga's only have one floppy disk drive power connector. If they plug it into this board what will they plug into their floppy drive? Perhaps you could have a built in power cable splitter? Easiest way would be to soldering some short wires (with hot glue to fix them) directly to the PCB and have a floppy disk power at the other end? (I think this is thought 2?)

A silk screen on the PCB with pin 1 on all connectors.


How does it work? It doesn't look that complicated. A single Quad input NAND buffer!?

Does it work with original disks with copy protection? I am sure that someone on this board knows which games were the worst behaved. (i.e. the best to test with)

Look at the first picture where the power socket is, there is an extra set of holes that the second power lead goes to. The board splits the power.

It would be ideal to have the IDE connecter plug straight into the drive but you will find different manufacturers place the orientation differently. On one drive it would be one way on another the opposite. It could I suppose be made to fit the motherboard instead. Then a lead to the drive.

Ian, number 3 is a definate I think

[AlfaRomeo]

Great stuff Stedy

[TheCorfiot]

Stedy

Excellent stuff oh miggy hardware guru

Agree with Alex totally if we could have a 34 way pcb mounted female socket on one side plugging straight into the FDD (can assume PC floppy drive is set as std to drive 1), with a Male plug on the other side taking the feed straight from the miggys original mobo floppy cable.
The existing power lead could also plug into the board, with a short directly soldered PSU flylead to connect to the floppy drive & supply power to it.

This would allow direct retrofit to an A2000 / A500 / A1200 etc

You can put me down for one of these for sure.

Well done mate appreciate your support & commitment.

TC

[keropi]

I would take one too!

[Stedy]

Hi,

The PCB design will get updated. The existing layout was done for ease of construction using the PCB equipment I have at home.

Alexh's suggestion of connecting it directly to the floppy drive is good. I ahve already modified the layout so it is only a few mm wider then the 34 way IDC cable so it will fit. I did consider plugging into the floppy connector but there is no room on my A600 when the drive is installed in the normal place!

The prototype board should have had 2 power connectors but I put the 2 sets of holes to close together and could not get 2 x Molex KK connectors in. For a final design, a flying lead, soldered to the PCB with 10cm of cable should suffice. Different drives have the power connector in different places.

Rough costing, assembled unit £7-8.

I have found a source of cheap (£1.50) 600 mm FDD cables which could come in handy for tower users.

I don't take pre-orders. When units are available, you can order.

Can anyone suggest any games to try the modified drive/adaptor out with?

I really need to practice with Speedball 2, I lost badly

Have a few more projects in the pipeline. When there are working prototypes I will announce them. A few of them are more complicated than a single TTL device too!

[Eclipse]

Hi Ian,
Just my findings so far:
Random old drive and a new Sony MPF920 both worked.
The following games worked as well:

Sensible World of Soccer 95/96
Trolls AGA
Frontier Elite 2
Premier Manager 2
Speedball (using SKick).

All the above games were original boxed versions.
I'm sure that Lotus 2 was one game that was picky about the floppy drive and maybe Speedball 2. I only have copies so those would be no good.
I will look on ebay for you unless anyone wants to lend some games out or a 1:1 copy (X-Copy and Dongled).
Other than that it has worked with all adf's that I've put to disk.

[X-ray]

Stedy, good job: put me down for two of those.
If I had my preferences, the power would be supplied via wires directly soldered to the board, ending in a standard molex plug (like CPU fans). I can then choose how to supply power.

[twizzle]

stedy put me down for 1 aswell , great invention by the way

mmmm just a thought? is it worth applying for a patent ?
before elbox gets wind of it ( ROYALTY`S )

[cosmicfrog]

great work dude, Looks like I`ll be wanting 1 too

has any1 tried xcopy with it yet ?

[Jope]

Try Sanity's Arte.

[Stedy]

Hi,

@Jope,

I tried Sanity Arte, it worked with no issues.

From what I remember Pinball Dreams/Fantasies was a tricky one, I know I have the original disks somewhere.

@Cosmicfrog

I used Dcopy 3.1 to nibble copy a few games, no issues encountered.
Will check my 600 disks to see if I have Xcopy.

@thread

Looks like I need to provision a flying lead for the floppy drive power, especially for retro fit to existing units. Will locate the correct connector.

I'll prototype the revised PCB design before mass production, hopefully by 5/6th september.

Here we may hit a scheduling issue. It takes 3 weeks to get the PCBs, so if I order on the 10th September, they arrive October 1st. I go away October 15th for a month Does not leave much time for production/deliveries. See how the time goes.

What other demos and games shall I try?

Another thought, could I add a jumper to counteract the Escom A1200 floppy fix?
This would save soldering the motherboard. Any details around?

Ian

[cosmicfrog]

my birthday is 12 oct so could be a nice bday presy for me and the amiga

keep the ideas comin and my the Ribbits be with you

[Eclipse]

Originally Posted by Stedy

What other demos and games shall I try?

Another thought, could I add a jumper to counteract the Escom A1200 floppy fix?
This would save soldering the motherboard. Any details around?

Ian

If it worked with Sanity Arte it will work with most I'd say. That demo is a sure sign it's a winner.
Here's a list of some copy protections and what they were on. I think the ex crackers on here could maybe mention a few good ones.

If you added a jumper to counter-act the Escom "fix" I think you'd become Saint Stedy.
Here's the SPS (CAPS) article. Clicky
Talking of which, it would be good to see how a CAPS dump compares.