How Hard to Use Floppy For Flasher?

[sherial]

I notice many microcontroller projects actually use the serial, Parrallel, or USB for the Data transfer and Flashing Process... My question is:

How much trouble would it be to have the PIC read its info from a standard Floppy drive? Therefore, you could copy your Programs to floppy disk and use the disk to flash the Microcontroller (PIC)..

Would make your PIC more mobile... Is this a problem creating?

 

[Nigel Goodwin]

I suggest you search back over the last 20 years or more, it's been discussed endlessly - it's EXTREMELY difficult to attempt to use a floppy disk with a PIC, for a start you don't have enough RAM. A floppy disk is probably the worst possible idea for transferring programming data.

 

[crutschow]

When is the last time anyone used a floppy disk? Computers haven't had them for years.

 

[Nigel Goodwin]

When is the last time anyone used a floppy disk? Computers haven't had them for years.

Somewhere I've got a little Sony device, it accepts a standard video feed, and when you press a button on it it saves a still image of the video at that moment to a 3.5" floppy disk as a JPEG

One of the more interesting uses I've seen.

 

[ronsimpson]

There some large serial memories that talk SPI. Most PICs talk SPI. There should not be read errors and seek errors and write errors. I think you can read/write in small blocks which is nice when using a small memory computer like a PIC.

 

[dougy83]

How much trouble would it be to have the PIC read its info from a standard Floppy drive? Therefore, you could copy your Programs to floppy disk and use the disk to flash the Microcontroller (PIC)..

It should be possible but IMO not worth it. The floppy drive is large, power hungry, of low reliability and very outdated.

Would make your PIC more mobile... Is this a problem creating?

I can only see it making the PIC less mobile. Have you had a look at SD cards? They're much smaller, faster, have greater capacity, are easier to interface to, much more robust and have a much smaller power requirement than a floppy drive.

 

[Nigel Goodwin]

It should be possible but IMO not worth it.

I refer you to post #2 - it was attempted for MANY years, and as far as I'm aware no one managed it.

 

[dougy83]

I refer you to post #2 - it was attempted for MANY years, and as far as I'm aware no one managed it.

I'm not sure why you're referring me to post #2. It is quite obvious that interfacing to a floppy disk is possible; it has been done on many low-end devices over the years. A floppy disk controller IC allows the drive to be accessed through an address-mapped interface using commands such as "read sector" and "write sector", see https://www.isdaman.com/alsos/hardware/fdc/floppy.htm

 

[Nigel Goodwin]

I'm not sure why you're referring me to post #2. It is quite obvious that interfacing to a floppy disk is possible; it has been done on many low-end devices over the years. A floppy disk controller IC allows the drive to be accessed through an address-mapped interface using commands such as "read sector" and "write sector", see https://www.isdaman.com/alsos/hardware/fdc/floppy.htm

Which isn't 'accessing it via a PIC' and where is the memory coming from to store the sectors?

Why not just have the floppy drive in an old PC and a serial connection to your PIC if that's all you're 'interfacing'

 

[dougy83]

Which isn't 'accessing it via a PIC' and where is the memory coming from to store the sectors?

Why not just have the floppy drive in an old PC and a serial connection to your PIC if that's all you're 'interfacing'

If it's not using a pic to read info from a standard floppy drive, then what is it?

 

[Nigel Goodwin]

If it's not using a pic to read info from a standard floppy drive, then what is it?

It's using a big pile of chips to read data from a floppy drive

 

[dougy83]

It's using a big pile of chips to read data from a floppy drive

No, it's using a single chip to provide a simpler interface to the floppy drive. Similar using an ENC28J60 (or W5100) to provide an interface to ethernet or some other interface chip for a different interface.

 

[Nigel Goodwin]

No, it's using a single chip to provide a simpler interface to the floppy drive. Similar using an ENC28J60 (or W5100) to provide an interface to ethernet or some other interface chip for a different interface.

But isn't that chip designed to connect to a micro-processor, and requires a decent amount of RAM to allow it to be used - something you can't add to a PIC.

Like I said previously, this was debated endlessly for MANY years on the PICList - as far as I'm aware there was never a successful outcome?.

 

[dougy83]

But isn't that chip designed to connect to a micro-processor

Yes. It has only a few IO port addresses, some control lines and a data bus.

requires a decent amount of RAM to allow it to be used - something you can't add to a PIC.

According to the aforementioned linked docos, every time a byte is expected to be read or written a HW interrupt can be signaled. Max datarate for a 1.44MB disk/drive is 500Kbps. Sector size can be between 128 and 1024 bytes, though of course it's possible to only heed fractions of that during reads.

something you can't add to a PIC.

You can add RAM to a PIC.

Like I said previously, this was debated endlessly for MANY years on the PICList - as far as I'm aware there was never a successful outcome?.

The flatness of the earth was likely debated for many years in many forums too.

 

[Nigel Goodwin]

Yes. It has only a few IO port addresses, some control lines and a data bus.
According to the aforementioned linked docos, every time a byte is expected to be read or written a HW interrupt can be signaled. Max datarate for a 1.44MB disk/drive is 500Kbps. Sector size can be between 128 and 1024 bytes, though of course it's possible to only heed fractions of that during reads.
You can add RAM to a PIC.

Perhaps you would care to show us how? - at least in any half way usable fashion.

The flatness of the earth was likely debated for many years in many forums too.

I look forward to you posting your floppy drive PIC project in the next few months then

 

[atferrari]

My question is:

How much trouble would it be to have the PIC read its info from a standard Floppy drive? Therefore, you could copy your Programs to floppy disk and use the disk to flash the Microcontroller (PIC).

Your original question was answered, short and to the point. Now you try to refute the answer.

Plain exercise in futility. Enough for me.

 

[voidptr]

Quote Originally Posted by sherial View Post
My question is:

How much trouble would it be to have the PIC read its info from a standard Floppy drive? Therefore, you could copy your Programs to floppy disk and use the disk to flash the Microcontroller (PIC).
-------------------

I'm sure you can do it !
Sony floppy controller can be program with 8bits micro controller for sure !

we (me and my school mate) did that 20 years ago with a Motorola 6809 !

I was awesome to for the first time be able to format a track, and format the complete disk, then read at file and track from on disk and write it to another one!
You will learn alot about uP, and interface with mechanical interface, some magnetic stuff too, and old file structure, track, sector, TOC, etc etc )

Here some hints :
we seach for 1 complete night why suddenly we were not able to format one track again ...
check info on pre - compensation when reading/writing P

Take a Pic with DMA channels, without them you will not be able to have really great io speed... well maybe with a Pic at 20MHz you will be fine, our 6809 was quite slow compare to today clock, darn i can't remember the clock ... ( maybe 1MHz) ...

you surely will have fun to do it. we did and got something like 95% on that school work )

the real utility of all that now will be really none existant, but
next step will be to design your own hard-drive controller, there still some improvement to do there!

 

[ghostman11]

i have no idea of the purpose for this but a few thought's, if its for a project and not just something you want to have a try at (wich is cool, trying stuff to see if you can do it is alot of fun) then a SD card would give you better speed and capacity and like a floppy you could swap from project to project. also less power needed and Cheappppppppppp. plus plenty of info on how to do it, another option is build something that looks like a usb device with a small board inside and a few eeproms. i think my favoured approach would be the sd card.
but like i said if this is a 'i want to see if i can' type project then interesting idea keep us informed
best of luck and have fun

 

[Nigel Goodwin]

I'm sure you can do it !
Sony floppy controller can be program with 8bits micro controller for sure !

we (me and my school mate) did that 20 years ago with a Motorola 6809 !

A 6809 ISN'T a micro-controller, it's a fully fledged micro-PROCESSOR, with access to up to 64kbytes of RAM - while a PIC is faster than a 6809, that isn't the issue, the issues is that a few dozen bytes of GPR's isn't enough to run a floppy.

A 6809 was commonly used with floppies. that's the era (and before) that floppies came from.

 

[Ian Rogers]

I don't see why you are having this conversation.... A pic16f877a or equivalent.. with a FD controller chip and a 23k256 SPI sram.... Job would be relatively easy..
Or even a 8051 derivative connected to a 32k memory chip..

BUT WHY!! I didn't even think you could buy Floppy disks any more... As was previously mentioned... Extremely unreliable, outdated FAT14

You would be better using your time connecting SD card to a small pic and the 32k SPI sram....

Just my take...