Raspberry PI as a real Amiga Floppy Drive

[kipper2k]

Here is picture of what the board would look like actually mounted, showing an A600 cable in place and the Pi header. The board will probably be shrunk a bit on the left side to make it a bit smaller, the 4 pin floppy power cable will be same as floppy drive header, right angled mounted..




here is link to full sized pic

http://www.kipper2k.com/amigaforsale...ounted_big.jpg

[alexh]

There is a slight difference between A1200's isn't there? Some were designed to take unmodified PC drives?

[kipper2k]

IIRC there was a jumper wire on the later ones that modified the floppy drives (Escom?). I remember removing it on one of my 1200's to restore a regular floppy drive

[mram]

Originally Posted by kipper2k

I will send my board for fabrication this weekend, i will get a few for testing before i submit a final order. I intend on selling as a kit or complete... preferably as a kit as i have lots to do, price won't be too high, board size is pretty big so i reckon about $8 - $10 each for the board alone. The rest of the parts are not too expensive. custom size cables would be about $4 each (Pi, A600 and a500 etc) if you need them made. Resistors and diodes are cheap. A ballpark figure for just the components and board is about $19 (not including cables), if i build/test it then add $10. The hardest soldering would be the logic chip, but it is not too hard if you use the right tool for the job . Price doesn't include a switch, haven't for sure decided which one/type to use, they range from $1.50 - $10

The jury is still out on the switch(s) so this order would be considered the beta of my design

Very very good, and it is really an honest price. It's right to consider a board like a"beta", because this solution is young and there are lot of options available. But most of them are only software updates and this solution is the best for people who don't want or don't know how spend time to build it.

Good work

[mram]

Originally Posted by kipper2k

Here is picture of what the board would look like actually mounted, showing an A600 cable in place and the Pi header. The board will probably be shrunk a bit on the left side to make it a bit smaller, the 4 pin floppy power cable will be same as floppy drive header, right angled mounted..




here is link to full sized pic

http://www.kipper2k.com/amigaforsale...ounted_big.jpg

Wow!! Never seen before a RED Raspberry PI! Really cool ! where did you get this?

[kipper2k]

Originally Posted by mram

Wow!! Never seen before a RED Raspberry PI! Really cool ! where did you get this?

Ebay

http://www.ebay.ca/itm/CN-Ver-Raspbe...01a165b&_uhb=1

[kipper2k]

I do have an older Rev 1 too so i will try both.

I think i got all the bugs sorted so i will be putting in an order for some boards tomorrow morning, so about 12 - 15 days and hopefully be good to test.

[desiv]

Just a thought, any possibility about some further connections to the Amiga?
Initially, the easiest I can think of would be to the Amiga's serial port and use something like tcpser on the PI to emulate a modem for telnet BBS/file transfer, etc..
(That would probably have to be a cable from the Amiga serial port looping back IN to the Pi?)

Crazier Pi in the Sky (sorry, couldn't help it) would be a connection to the clockport for something there?
Or are we pushing so much thru the Pi already with the floppy stuff, that anything else would be frowned upon?

desiv

[Amiga1992]

Originally Posted by desiv

Or are we pushing so much thru the Pi already with the floppy stuff, that anything else would be frowned upon?

It was said before that this application does not run any sort of linux distro on it so it can't do anything but being a floppy emulator.

[desiv]

Originally Posted by Akira

It was said before that this application does not run any sort of linux distro on it so it can't do anything but being a floppy emulator.

Ok, so you can't do Linux stuff with it, but that doesn't mean it can't do ANYTHING..
It can do whatever the person who is programming it wants to..
It just adds multiple levels of complexity to it... Making it much less likely. ;-)

Also, this post makes me wonder if it can't be done with Linux on the Pi:
http://eab.abime.net/showpost.php?p=923362&postcount=7

desiv

[Amiga1992]

Yeah of course, given that you reprogram the kernel, you can do whatever you want

[alexh]

Originally Posted by desiv

Also, this post makes me wonder if it can't be done with Linux on the Pi: http://eab.abime.net/showpost.php?p=923362&postcount=7

Of course it can. But Raspbian Linux takes (with the fastest class 10 SD card + USB install) about a minute to boot. Whereas this custom software takes roughly 7 seconds.

Would 1 minute be acceptable each time you power cycle your Amiga?

[mram]

Actually the Raspberry was pushed a lot near its limits... hardware limits. The floppy emulator is a HARD real time application, Linux on Raspberry PI as it is can't manage it.

But the real question is, WE REALLY NEED THAT? For what in concrete?

What you really want to see/do on your Amiga? How much time/money do you want to spend to do that?

Remember this is a floppy connector, so finally very slow for today standards and you can't do nothing to make it faster. If you would like to do something "advanced" better is to use other ports, like the expansion port. It has really no sense spend so much money (130 euro or more) for old shit hardware to have no-sense, useless solutions that finally really sucks. An ACA-500 or other expansion port interfaces, for less money..., represent a REAL significant improvement. IMHO 5-20 euro interface to connect Raspberry PI to Amiga using the old floppy connector represent a reasonable solution for what this FLOPPY CONNECTOR can do. Spend more than 5-20 euro today to attach dedicated hardware to the Amiga's slow floppy connector it is just a waste of money (and time)

As a Raspberry PI is good new hardware, it can be pushed a little bit to do a lot more than just a simple "floppy emulator", a lot improvements can be made for free just by software using all the hardware it is already on this board.

A lot more can be done by Raspberry PI for sure, we can use the external display to improve the choice of program/games (perhaps a nice coverflow selection...), we can use its hardware to connect and download programs from internet without removing the SD (ok, no such a problem because on a single SD you could have all the Amiga software ever made...) but this is the best we can do in terms of price/performance using the floppy connector .

[desiv]

Originally Posted by alexh

Of course it can. But Raspbian Linux takes (with the fastest class 10 SD card + USB install) about a minute to boot. Whereas this custom software takes roughly 7 seconds.

Would 1 minute be acceptable each time you power cycle your Amiga?

I have an Amiga 1000 with a boot floppy that redirects to the tomthul dual IDE/CF cards.

A 1 minute boot doesn't bother me at all.. ;-)
(I even still use floppies pretty happily with the 1000.. Although I probably wouldn't want that on my 1200.. ;-)

But, I totally understand if it isn't worth it...
It's not a big deal at all...
IF there was spare CPU for it, it might be kind of neat...
But it's nothing critical...

Just wondering...

Thanx,

desiv

[alexh]

If I understand correctly, mram has done the hardware job of the "HxC floppy emulator" in software? This is where the real time requirements have come from?

His (and Kipper2k's) Raspberry Pi PCB is a cheap passive interface between the Pi and the Amiga floppy disk drive interface?

So I must change what I said earlier to "You could use linux but only if you had a HxC USB interface _AND_ your RaspberryPi." (i.e. 2x the price)

[kipper2k]

Can't order the boards until 7th Feb, Chinese New year so everyone has downed tools i guess, seems a lot better than our 2 days off xmas/New year that we get, but i digress.

I have 10 days to add/change to the board before i submit it so let me know if theres any requests for headers/test points etc....

Here is the board i am going to submit...





The mainboard mounting holes line up with the a500/a600/a1200. The a600 cable header will be Right angle mounted which should allow clearance for the HDMI output of the Raspberry if ever needed. Holes for the Raspberry mounting are on the board. I added a couple of pads for those that want to mount the LED somewhere else. Switch design is changeable.

I shortened the length of the board to 5" and the width is the same width as a floppy drive so it should sit properly in all machines

For those guys looking at the schematic, remember, the ground plane is not shown so it would probably look incomplete to some of you

[Higgy]

I just spotted this. Nice work making your own board.

I was thinking of ordering all the bits and making my own from the original guide, but with your board it is looking a lot easier to do.

[alexh]

Out of interest, is there an activity LED header?

If this board were used in an external drive (CDTV) or the A2000/A3000/A4000 I believe there would be no activity LED as all of these units use the activity LED on the floppy drive itself?

[kipper2k]

Originally Posted by Higgy

I just spotted this. Nice work making your own board.

I was thinking of ordering all the bits and making my own from the original guide, but with your board it is looking a lot easier to do.

Thanks, i will order a small amount to verify my work and then i will let it loose

[kipper2k]

Originally Posted by alexh

Out of interest, is there an activity LED header? If this board were used in an external drive or the A2000/A3000/A4000 I believe there would be no activity LED as all of these units use the activity LED on the floppy drive itself?

I think the LED for this board is actually for reading track change, i don't know if that would apply to all disk drives mounted, would need to ask Mram, i did add 2 pads, i can also add a 2 pin header at the back of the board too (consider it done).

I'm also thinking of a way to prevent someone accidentally putting in connector backwards and feeding 12v. I am thinking of using a 5.1 Zener on the 5v leg but not sure how to add it to circuit