knusperfisch

Ok, maybe that causes the misunderstanding: From firmware "documentation": vers. >=3.0 : Builtin very simple TURBO loader (for 7th bit mode - turbo mode similar to one used in XF551)

I found that out in the meantime too, and tried to resolder the PIO wires from pin 15/16 to pin 16/17 like it's written in the last article of the series. It turned out that the whole memory area does not work at all after this modification. I need to probe the PIO pins. If I do not find out what's wrong, I'll remove the entire botch, replace RAM and PIO if necessary, and install a commercial RAM extension like ultimate 1mb or so.

exactly, and then some sectors of fast SIO routines are preloaded (if "topdrive" is set to "1" in sio2sd config) and you have to press select or start to boot the atr in high speed.

I found out that everything works fine if I do not preload the fast SIO routines from sio2sd. Of course the 1050 can't handle fast SIO but sio2pc responds even when sio2sd-D1 is empty. This makes it look like it is a sio2sd problem rather than a 1050 problem. Problem vanished

There is no 1050 involved, what do you mean? I reckon that lw.exe overwrites memory used by the fast SIO routines which causes them to crash. I don't use a patched rom (yet).

I figured out that it only freezes with SIO2SD's fast SIO routines preloaded. Runs fine with slow SIO or in an emulator. Maybe the problem is not mainly the layout of the RAM extension?

Are there SIO2SD firmware developers around to help?

btw. Last Word does also freeze at the same stage on stock Atari 800 XL with 64K....

I recently scored five SIO cables and a CX40 joystick

Oops, seems like my last post is lost after the downtime today. Ok, again: Memory extension is self built after an article in german Atari Magazin in the mid 80's. It has a different bank layout, at least different to Compy Shop extension. Every test program reports ok, but last word freezes at "Loading lw.sys" even if all config files werde deleted before. Numen demo does not run (freezes with black screen after loading demo). Turbo Dos ramdisk works fine. I think I need to alter the bank layout to make the extension Compy Shop compatible.

Thanks! This tool shows 16 banks, 256 KB and the test result is ok. But every program which actually uses extended memory crashes on my machine.

Hi, is there somewhere an extended memory test program which shows the type/name of extension and test if it works properly? Thanks!

Thanks to all af you, I figured out the concept of virtual drives. It is something like "mark your favourite disk images for quick access". Calling it "Virtual drives" confused me first, because I consider SIO2SD itself as a bunch of "virtual drives" (namely D1-D16).

Maybe, Copy program shows Error 138 = Device timeout

Too bad the SIO2SD pcb does not have the standard 3x2 AVR ISP header, to flash with USBtinyISP.