SIO2 1541

[Rybags]

Has this been done?

OK, the more appropriate quesion might be "Why would you ever want to?"

 

Still, it would be an interesting exercise. I might give it a go if it's not been done.

But, some technical info would be needed... what exact transmission rate is used. Overview of the command set and protocol.

 

Actually, thinking about it some more, it might come in very handy, people who already have APE could use it to get D64 images onto floppies as an alternative over X1541 type interfaces.

[dwhyte]

Has this been done?

OK, the more appropriate quesion might be "Why would you ever want to?"

 

Still, it would be an interesting exercise. I might give it a go if it's not been done.

But, some technical info would be needed... what exact transmission rate is used. Overview of the command set and protocol.

 

Actually, thinking about it some more, it might come in very handy, people who already have APE could use it to get D64 images onto floppies as an alternative over X1541 type interfaces.

 

You might have to turn those .D64s to .DCMs for proper transfer over APE I think...

[candle]

1541 has "dos" inside, beside that its 6502 based, and capable of running external (after upload) code

every fastloader would fail if you won't emulate this

bottom line is - ape is no good for this

[sup8pdct]

I have heard that the C64 serial was 1200 baud to/from the drive which is why speed ups were so popular.

Hell, the atari can bitbang that out the joystick ports during the VBI (well, almost)

 

James

 

 

 

Has this been done?

OK, the more appropriate quesion might be "Why would you ever want to?"

 

Still, it would be an interesting exercise. I might give it a go if it's not been done.

But, some technical info would be needed... what exact transmission rate is used. Overview of the command set and protocol.

 

Actually, thinking about it some more, it might come in very handy, people who already have APE could use it to get D64 images onto floppies as an alternative over X1541 type interfaces.

[emkay]

What about thinking of a real DMA controller, using the parallel port of the A8?

Everything else is wasting time.

[Rybags]

To clarify - The intent is to hook a 1541 to the Atari, APE isn't involved in the exercise, only a sideshow participant if you happen to want to transfer stuff to/from a PC using the Atari as an intermediary.

 

So, the hookup would be SIO... hoping to do it that way, the alternative of course is bitbanging through the joystick port, which I'd prefer not to resort to.

 

I'm aware of the fact it has onboard DOS etc. but have little idea of the command set at the low-level. All I know is that Commodore serial attached devices are similar to those of Atari in that they use an Attention signal, send a device ID and wait for response, then do the command etc.

Edited April 25, 2009 by Rybags

[spookt]

Just out of interest why do you want to do this? I don't really understand what you would achieve.

[Rybags]

Why? Why not?

 

Just for the sake of doing it, really. And, it might have some other use, such as a potential networked game that runs on both machines.

[spookt]

Cool - I just wondered if you had a particular use in mind. I'm all for the "because we can" argument

[carmel_andrews]

A better Idea would be to hack the Happy o/s software to allowing you to convert certain c64 files to A8...after all Happy already allows you to convert/read old ibm pc files to an A8

 

by happy o/s software, i mean the disks the upgrade came with

[candle]

carmel: are you familiar with byte encoding schemes used in commodore drives, and atari ones?

wd series controllers are capable of doing fm/mfm encoding only, commodore uses gcr - this is a bit of a problem...

 

rybags: here is something that might be worth of looking at

http://www.bitcity.de/1541%20Serial%20Interface.htm

Edited April 25, 2009 by candle

[ijor]

carmel: are you familiar with byte encoding schemes used in commodore drives, and atari ones?

wd series controllers are capable of doing fm/mfm encoding only, commodore uses gcr - this is a bit of a problem...

 

[irony mode]

No problem whatsoever. Who needs real C64 disks? Store the C64 disk images in a DOS single sided disk. The Happy can read it.

[/irony mode]

 

No idea if this is what Carmel was thinking, but it is doable. At least the part of reading the C64 disk images, I don't know if you need extra output signals on the SIO connector, that not even enhanced drives provide.

 

Yeah, a bit of insane, but we talk about some insane ideas here all the time. Wasn't Bryan method of transferring data from the A8 to the ST "somewhat" insane? It was possibly totally insane, but I think his post one of the most interesting posts on Atariage lately (thanks Bryan for sharing your insanity )

Edited April 25, 2009 by ijor

[ataridano]

carmel: are you familiar with byte encoding schemes used in commodore drives, and atari ones?

wd series controllers are capable of doing fm/mfm encoding only, commodore uses gcr - this is a bit of a problem...

 

rybags: here is something that might be worth of looking at

http://www.bitcity.de/1541%20Serial%20Interface.htm

 

I would buy one! It would be useful to transfer disk images to my VIC20 Commodore uses GCR for the 1540 and 1541, but the 1570 and 1571 do both GCR and MFM, and the 1581 is MFM only. It may actually be possible to build a device that translates SIO commands to C= and lets you read/write Atari disks in a 1571 drive transparently. Of course with MIOs and SIO2SD and SIO2USB there is probably not much demand for such a device, yet it's still a neet idea

[sup8pdct]

I have found a little bit on info here http://www.classic-games.com/commodore64/drives.html.

Nothing about the serial however.

Maybe time to pull apart the kernal to see what happens.

 

James

[Rybags]

The info I need should be out there... since there's so many fastloaders around, the Kernal is probably known backwards by some people.

[brighty]

The info I need should be out there... since there's so many fastloaders around, the Kernal is probably known backwards by some people.

 

Hey Rybags,

 

I have feet in both Vic20/A8 camps and own both an 800XL and VIC20 + 1541. A good source of information on 1541 interface and protocols is Jan Derogee's pages here. He produced the 1541-III MMC/SD card IEC device (which I also own). It has invaluable info on protocol and interface details.

 

His overall project page is here

 

HTH

 

Steve

[Rybags]

Cheers, that should help quite a bit.

[sup8pdct]

If I am not mistaken, there are no start or stop bits. Looks like the joystick ports are the way to go.

Easier to get the kernal and mod it a bit to work.....

 

James

[Rybags]

I kinda feared that.

 

Although... I wonder if we can bit-bang through the Atari serial port... we can read that way no problem.

SKCTL has a Force Break bit... maybe we can use it to control output of 0/1.

 

Anyway, this has to take position 3 in my todo... I've dragged the chain on the Interlace stuff. Then Pole Position + speech version needs finishing.

[Bryan]

Yeah, a bit of insane, but we talk about some insane ideas here all the time. Wasn't Bryan method of transferring data from the A8 to the ST "somewhat" insane? It was possibly totally insane, but I think his post one of the most interesting posts on Atariage lately (thanks Bryan for sharing your insanity )

Ask my wife- I don't have much else to share.

[ijor]

If I am not mistaken, there are no start or stop bits. Looks like the joystick ports are the way to go.

 

Although... I wonder if we can bit-bang through the Atari serial port... we can read that way no problem.

SKCTL has a Force Break bit... maybe we can use it to control output of 0/1.

 

The low level protocol seems to be somewhat similar to I2C or "Two-Wire". Serial synchronous, half-duplex, with the clock signal used for flow control. You do can bit-bang the SIO Out using Force Break, but I think that won't be enough.

Edited April 27, 2009 by ijor

[ijor]

(thanks Bryan for sharing your insanity )

Ask my wife- I don't have much else to share.

 

No need to, it was more than enough But seriously, I consider that method you used as really cool. Completely insane, but extremely cool

[Bryan]

I hope someone gets this working so we can finally play those 64 games they keep bragging about!