SDrive high speed SIO?

[R.Cade]

I have an SDrive from a batch made by a member here a few years ago. (Identifies itself as SDrive01 20081012 Bob!k aand Raster, C.P.U.)

 

Is there any easy way to speed it up to high speed SIO support? I have tried using the keys to change the FastSIO to $01 and $00, and also patched and burned a new AtariXL.rom for my 800XL with the Hisoft(?) patcher, but it seems no faster no matter what I try. Is there something I am missing or does it not work on this device?

 

It seems much faster booting from serial SIO to APE...

 

-Pete

Edited December 1, 2013 by R.Cade

[Rybags]

Don't have one myself (got SIO2SD) but I think you might find most luck in seeking a firmware update for the device itself.

 

Faster SIO is a joint effort - the OS or Dos on the computer side needs to support it and the device also. Generally the Dos will try doing fast SIO and knock the speed back down if it doesn't succeed.

[Roydea6]

@R.CADE,

Sdrive.com to get into the sdrive Menu the press the 'U' button until you get around $04,$05 then CONTROL 'W' press U and the Y this will update the SIO setting to hardware. INV key to reboot... assuming you have selected the atr image to boot...

When back into SDX type DIR A: OR D1: then type SIOSET this will tell you the speed setting on the Sdrive.... If it works good at $04,$05 then you can experiment with lower setting until you get to $00,$01 or find the sweet spot the hardware will work with..

 

 

You might also need to upgrade the bios on the sdrive to a newer version. I use 2.5 but there is a higher version available.

 

Have you removed or cut the SIO resistors from the Atari...

Also you might have to change the config.sys DEVICE SIO /A to use the OS 'Hias' patch. Not sure about this but works for me..

[BillC]

You might also need to upgrade the bios on the sdrive to a newer version. I use 2.5 but there is a higher version available.

I think you are confusing the SDrive & SIO2SD when talking about firmware v2.5 & higher, AFAIK there have only been 2 releases of SDrive software/firmware and these are by date: SDrive081012.zip & SDrive20090403.zip

[HiassofT]

A few years ago I updated the SDrive firmware so that you can use POKEY divisors 3 and below (you also need my highspeed SIO patch in the OS or MyPicoDos).

 

It seems I had totally forgotten to link the updated firmware from my homepage. I've now added it, you can download the latest firmware (sdrive-hias-090705.zip) from here:

http://www.horus.com/~hias/atari/#sdrive

 

so long,

 

Hias

[R.Cade]

Thanks guys. I opened up the device, and the board says it's an SDrive "micro". There appears to be a 5-pin programming port? I will have to find my AVRISP programmer if I have one... I was hoping it would be a DIP microcontroller so I could just pull it and program on my standalone burner, but no such luck.

[R.Cade]

Does it not ever boot the initial sdrive.atr at high speed, or does it only work after a reset?

[R.Cade]

OK, I got it to work.

 

I stupidly was trying to replace the BASIC ROM in the machine with the new XL OS ROM (with an adapter). I replaced the correct ROM and it works fine. I was not able to update my SDRIVE to newer firmware, but mine seems to work fine at the $02 speed.

 

It appears I broke my BASIC ROM in this process as well, since the machine now boots to the self-test instead of BASIC with no drive attached. Not a big deal, though. Anyone have any spare BASIC ROMs? (I already burned a new MMU with 16v8 so I know it's not that).

[Kyle22]

Anyone have any spare BASIC ROMs? (I already burned a new MMU with 16v8 so I know it's not that).

 

If you burned a GAL16V8, you must have a programmer. Get a 68764 or 68766 EPROM and burn BASIC on it. It plugs right in.

[R.Cade]

Thanks - I did burn to a 27256 (x4) with a 28->24 pin adapter and this works.

 

Any reason not to leave this socket blank and just use a BASIC cartridge instead?

[Kyle22]

If you have on-board BASIC and a cart, let's say Assembler Editor, you may switch freely from either language to SpartaDOS-X and go to either BASIC or CAR just by typing the command.

[BillC]

Thanks - I did burn to a 27256 (x4) with a 28->24 pin adapter and this works.

 

Any reason not to leave this socket blank and just use a BASIC cartridge instead?

Most BASIC cartridges are Rev.A while most 600XL/800XL came with Rev.B, both of which have bugs. Rev.C which came in XEs and later 800XLs is the final bug free version. The advantage of being able to burn your own is that you can replace Rev.A or Rev.B with Rev.C

[pseudografx]

Hi, I've got an answer by Bob!k himself:

"It depends whether you have resistors on the SIO lines (inside your Atari) or not. It also depends on software; the Hias patch might also help. I have never seen setting faster than 2 to work, except laboratory conditions (special OS, special loader) thus completly unusable for normal operation."

Bob!k himself uses the default speed "6", which is a de facto standard for fast turbos and should work 100% reliably on all machines and configurations (though there might be rare exceptions).

From what I remember, SDrive may work faster with QMEG OS, but as Bob!k says, you cannot set DIV to 0 there as QMEG assumes that as "no fast".

However, Bob!k has no idea regarding behavior of SDrive micro revision, which is not his implementation of the original design.

[HiassofT]

Well, getting the highest SIO speeds working can be somewhat tricky at the beginning, but it's not too complicated if you follow a few basic rules:

 

An important step is to remove the caps on the SIO line inside the Atari, especially the ones on DataIn and DataOut. Just clip them off, you won't need them.

 

If you have other peripherals connected to the SIO bus, also remove the caps on the SIO line in them. There are caps inside the 1050, for example, and if they are in place even standard high speed baudrates (divisor 10-6) can be problematic.

 

If you SDrive has the diode in the DataIn line (data input on Atari, output on SDrive), but no pullup resistor, add a 4k7 pullup to the SIO DataIn line (at the anode of the diode, on the SDrive PCB). This may help with signal integrity.

 

If you want to get divisors 2-0 running with SDrive, you also need my patched SDrive firmware - they won't work with the original SDrive firmware (it works around some POKEY weirdness, the UART inside the POKEY doesn't quite work as one would expect).

 

That's about it for the hardware side.

 

Now for the software part:

 

Most of the older highspeed SIO implementations, like that in QMEG, various DOSes etc have problems with low divisors. Using divisor 6 as a default value is a good chioce, this works with (almost) all highspeed SIO implementations.

 

If you go below that divisor, you need to use one of the newer highspeed SIO codes, like mine (BTW: the highspeed code in MyPicoDos 4.05 is identical to the one in my OS patch). The highspeed SIO code of recent SDX versions should also be quite OK, but I haven't tested it by myself (older versions still had issues).

 

At the highest speeds (divisor 0 and 1) you may run into problems if ANTIC steals too many CPU cycles. This is no problem if you are using the standard graphics 0 textmode, but keep in mind that it could cause problems in other graphics modes (especially widescreen modes, or if player/missile graphics is used in a textmode).

 

Following these rules I personally never experienced any issues with divisors 0 or 1 - both with SDrive and SIO2PC, transmission always was rock solid without any glitches.

 

OTOH: if you want stable operations in 100% of the cases (including widescreen modes, PMG, DLIs etc) without needing to think about it, better use a higher divisor / slower speed per default.

 

A good option is to use, let's say, divisor 6 per default and use the special SDrive version of MyPicoDos for loading games. This MyPicoDos version configures the SDrive to divisor 0 or 1 (selectable), so you can enjoy game loading at high speeds while having a safe default highspeed setting for all other cases.

 

so long,

 

Hias

[Subby]

You going to bring it, Pete?

I'd like to see it.

[R.Cade]

Sure thing....