55 replies to this topic

[candle]

it would be still wrong
lcx/lvc chips will provide 3.3V CMOS levels for SD card - this is nice, but still the output of 2.4V (being logic 1 for CMOS device powered from 3.3V rail) will be 0 for CMOS device powerd from 5V rail

but lets look at atari side
both POKEY and PIA has Vil=0.8V (logic 0) and Vih=2.0V (logic 1) and this suffice plus lvc/lcx families were designed to such tasks -  being 5V tolerant and providing TTL compatible outputs

[AtariGeezer]

I'll pass on this until a revised/corrected version comes out...

Jay

[HiassofT]

candle, on Mon Apr 30, 2012 12:05 PM, said:

it would be still wrong
lcx/lvc chips will provide 3.3V CMOS levels for SD card - this is nice, but still the output of 2.4V (being logic 1 for CMOS device powered from 3.3V rail) will be 0 for CMOS device powerd from 5V rail

Duh, you are right. Somehow I assumed the Atmels had TTL-compatible inputs, but after checking the datasheets I saw that V_IH is 0.6*VCC - that is 3V at 5V VCC.

So, yes, using VCC=3.3V for both Atmel and the SD-card, and using a 5V->3.3V level shifters for the SIO inputs (data_out + command from Atari) would be a correct setup.

BTW: another option would be to use an additional 3.3V->5V level shifter for the Atmel SDcard input, if the Atmel is running at 5V - for example something like the 74LVC4245 which has dual power supplies. But this requires one additional chip, so using a 5V->3.3V at the SIO side would be easier.

so long,

Hias

[santosp]

HiassofT, on Mon Apr 30, 2012 3:33 PM, said:

So, yes, using VCC=3.3V for both Atmel and the SD-card, and using a 5V->3.3V level shifters for the SIO inputs (data_out + command from Atari) would be a correct setup.

How do you use VCC=3.3V for the Atmel ATMEGA 32A while he need VCC=5V to work?

Maybe is good time to open a new thread titled "Research and Development about SIO2SD"!
Guys come on! Please explain to the people, how with so important mistakes  all devices sold to the present day  work? And after all, what we try to correct here? All the signal levels  from everywhere to everywhere, or specific the levels for SDcard - Microcontroller communication? ..........from which it seems is so important for some..........

Edited by santosp, Mon Apr 30, 2012 4:31 PM.

[sloopy]

HiassofT, on Mon Apr 30, 2012 3:33 PM, said:

candle, on Mon Apr 30, 2012 12:05 PM, said:

it would be still wrong
lcx/lvc chips will provide 3.3V CMOS levels for SD card - this is nice, but still the output of 2.4V (being logic 1 for CMOS device powered from 3.3V rail) will be 0 for CMOS device powerd from 5V rail

Duh, you are right. Somehow I assumed the Atmels had TTL-compatible inputs, but after checking the datasheets I saw that V_IH is 0.6*VCC - that is 3V at 5V VCC.

So, yes, using VCC=3.3V for both Atmel and the SD-card, and using a 5V->3.3V level shifters for the SIO inputs (data_out + command from Atari) would be a correct setup.

BTW: another option would be to use an additional 3.3V->5V level shifter for the Atmel SDcard input, if the Atmel is running at 5V - for example something like the 74LVC4245 which has dual power supplies. But this requires one additional chip, so using a 5V->3.3V at the SIO side would be easier.

so long,

Hias

Maybe i am not reading it correctly, but it seems the datasheet says you cant run the Atmega32 at 14.xMhz when running a Vcc of 3.3V. It only shows a graph for this but it might be possible, but would seem to be a fringe 'config' at best. It seems just under 4.5V would be the lowest Vcc that is useable...

sloopy.

[santosp]

<sub>Ok an update to to interested members about the so important 74HC245 who the original designer have use, and who is the  great diference from the Mega-HZ pcb. I decide to use in my pcb the proper 74LVC245 3.3v level shifter.  

Now for all the others who wait from Me to improve the signal levels betwen the Atari - SIO2SD, or the data out signal of SDcard to Atmel Microcontroller, just forget it. As you know I am not a developper, and I can not do experiments and tests.
My whole effort was based to a successful version of SIO2SD in a Micro complete with enclosure form, with  the lower possible price.</sub>

Edited by santosp, Mon Apr 30, 2012 5:51 PM.

[santosp]

_{Hi sloopy.
Just for your info. There exists 2 versions of ATMEGA32. The "A" and the "L". In first who go upto 16MHz the VCC must be from 4.5-5.5 volt range. In second who go up to 8Mhz must be from 2.7-5.5 voltage range. In latest pcb version of SIO2SD as you understand only the fast 16Mhz => 5Volt version can be used.}

Edited by santosp, Mon Apr 30, 2012 5:49 PM.

[BillC]

santosp, on Mon Apr 30, 2012 5:38 PM, said:

<sub>Ok an update to to interested members about the so important 74HC245 who the original designer have use, and who is the  great diference from the Mega-HZ pcb. I decide to use the proper 74LVC245 3.3v level shifter.  

Now for all the others who want to improve the signal levels betwen the Atari - SIO2SD, or the data out signal of SDcard to Atmel Microcontroller, just forget it. As you know I am not a developper, and I can not do experiments and tests.
My whole effort was based to a successful version of SIO2SD in a Micro complete with enclosure form, with  the lower possible price.</sub>

I was just curious in my post about why you hadn't included the 74LVC125 modification which was supposed to reduce the risk of damaging the SD card, you now appear to have resolved the issue by using the 74LVC245 which also does voltage shifting while staying pin compatible with the original 74HC245.

[HiassofT]

sloopy, on Mon Apr 30, 2012 5:15 PM, said:

Maybe i am not reading it correctly, but it seems the datasheet says you cant run the Atmega32 at 14.xMhz when running a Vcc of 3.3V. It only shows a graph for this but it might be possible, but would seem to be a fringe 'config' at best. It seems just under 4.5V would be the lowest Vcc that is useable...

I'd say you are correct.

In figure 28-2 on page 308 of the ATmega32A datasheet the supply current graph for 3.3V ends at 10MHz - so I'd guess this would be the limit.

The docs on the Atmel website are misleading, at best :-( For example the ATmega32A description on the website says:

Quote

The device acheives 16 MIPS throughput at 16 Mhz at 2.7-5.5V operation.

No "maximum" or whatever in this sentence. I read this as "16MHz accross the whole voltage range"...

so long,

Hias

[santosp]

For no other "misleadings" about the ATMega32 quote the above link with datasheets for the 2 versions.

http://www.atmel.com...ges/doc2503.pdf

[john-m]

I think a nice addition would be to be able to have an additional Atari SIO port for daisy chaining a SIO2PC device for easy transfer of files from ATR images from a PC.
Or am I missing something here?
Also, since it ends up as the last device, how would one use say a printer, plotter, modem, etc?

[kheffington]

Atari 850 interface should work

[john-m]

Maybe you did not fully understand my reasoning.  The Atari PC has one Atari SIO port.
So you connect the micro SD to it.
Where do you connect anything else that would require connection to the Atari SIO port.
We are looking at a dead end to the daisy chain once the micro SD is connected.
So any device one would want to connect would have to have 2 Atari SIO ports with the micro SD being the last device.
Am I making any sense now?

[john-m]

As an alternative, one could make an expansion hub that plugged into the Atari pc's sio port with additional SIO ports on the hub to be able to connect dead end devices.
It should not be too hard to do either as quite a few Atari peripherals have two SIO ports.
That way one would not end up with a dead ended daisy chain with no way to connect other devices to the Atari.

[Philsan]

John,
we understand your question.

This SIO2SD it too small to have a SIO port for daisy chaining.
Perhaps a second SIO cable could be added but it would be ugly.
Luckily most A8 hardware has a second SIO port so you can put SIO2SD Micro at the end of the chain.

[Philsan]

BTW, if you need a second SIO port you could ask user flashjazzcat to add it like in this SIO2SD/SIO2PC-USB:

[Fox-1 / mnx]

john-m, on Tue May 1, 2012 10:45 AM, said:

I think a nice addition would be to be able to have an additional Atari SIO port for daisy chaining a SIO2PC device for easy transfer of files from ATR images from a PC.

I take it you have a source where to get those SIO port chassis' at a reasonable price?

[john-m]

Actually, I do not have a source for Atari SIO port hardware.
And it was just a suggestion to add a port.
I have a 1020 printer-plotter that gave up the ghost and that gave me two ports in hardware I can use.  I would leave it to others to interface them to a cable for connection to the Atari PC.
I am sure there are others with dead Atari peripherals that could utilize the port hardware from them if they needed the additional SIO port.
In my case, I would like to be able to use the micro SD with the serial SIO2PC to be able to mount ATR images to transfer files to the micro SD.
So how does one otherwise get the files stored in ATR images transfered to the micro SD?
Just call me dumb. But I just am trying to save having to move the SD storage device back and forth to add files.
Using the SIO2PC interface with the micro SD, I could mount an ATR image as a drive and just copy needed files from that drive to the micro SD one.

[Philsan]

It's easy to transfer ATR images to SIO2SD Micro, especially if you have a PC nearby.
You take the SD card, you insert it into PC, you drag and drop ATR images, you insert SD card into SIO2SD Micro.

But if you want to use SIO2PC at the same time you can:
- buy AtariMax SIO2PC (USB or RS232) with 2 SIO ports:
http://www.atarimax..../documentation/
- let someone make for you an enhanced SIO2SD version with SIO port, obviously in a bigger case.
SIO2SD Micro case is too small to add a SIO port.

Edited by Philsan, Tue May 1, 2012 1:20 PM.

[Fox-1 / mnx]

john-m, on Tue May 1, 2012 12:44 PM, said:

I am sure there are others with dead Atari peripherals that could utilize the port hardware from them if they needed the additional SIO port.

True, but in that case the manufacturer can't finish the job as he doesn't have them.  A buyer has to mount them himself (requires some tools and skills) or has to send the connectors (takes longer and requires international shipping in most cases).

john-m, on Tue May 1, 2012 12:44 PM, said:

Just call me dumb.

If you insist :-)

john-m, on Tue May 1, 2012 12:44 PM, said:

Using the SIO2PC interface with the micro SD, I could mount an ATR image as a drive and just copy needed files from that drive to the micro SD one.

Using a SIO2PC device with dual SIO ports solves the daisy-chaining issue too.  There are many other ways to deal with the SIO ports problem.  You can built a SIO2PC interface into the Atari 8-bitter, or in a 1050 disk drive (or 1010 tape drive), or do what I did, mount a SIO2PC interface in the middle of a regular SIO cable.

[kurtm]

john-m, on Tue May 1, 2012 12:44 PM, said:

Actually, I do not have a source for Atari SIO port hardware.

http://nuxx.net/wiki..._SIO_Connectors

c0nsumer compulsively documents everything, it's nice.  

[Fox-1 / mnx]

kurtm, on Wed May 2, 2012 8:43 AM, said:

c0nsumer compulsively documents everything, it's nice.  

I know there are a few sources but not at reasonable prices.  Imagine the total cost when ordering two of these from the other side of the globe...

[Scarpad]

I'm interested in purchasing one in an enclosure, let me know the details and availability

scarpad@comcast.net

[santosp]

Hi Scarpad.
I am working that, and also I am in talks  with some alternative person with cnc laser local here. If all go well, a very limited production (about 20?)  will be run with some externally alterations. I will keep all you informed.
Thank you.

[SIO99]

Does this device or any other SIO2SD device actually allow users to SAVE programs to SD, as well as LOAD them?

I've recently bought an Atari 65XE with an XC12 cassette data recorder. So far my programs are very short, and take less than a minute to save or load, but as I progress, they will take a lot longer.