sup8pdct

here in australia, we had a terminal program written by john nicholls called mega term. it had a simillar interface to what you have except it was built into the case of a 25 pin shell serial plug. The chips are a 74ls126 and the 1489. this interface also has one of the rs232 signals going to one of the interupt lines. Motor control is used to enable the gates on the 126. your interface could be similar and could use the rverter driver. james Got a schematic? That sounds a lot like what I have except for the much smaller case. That might even be what my unidentified chip is (74ls126). It's got the right number of pins to match it. Thanks! BobKat Here is the megaterm interface. the extra gate connected to command and proceed won't be on yours. This is used by the megaterm software to detect the interface It may also not have the CD line detect. James

here in australia, we had a terminal program written by john nicholls called mega term. it had a simillar interface to what you have except it was built into the case of a 25 pin shell serial plug. The chips are a 74ls126 and the 1489. this interface also has one of the rs232 signals going to one of the interupt lines. Motor control is used to enable the gates on the 126. your interface could be similar and could use the rverter driver. james

I am quoting this from memory so if I am wrong, please correct. Ntsc colour system isn't very good, on some broadcasts, you can see the colour leading or following a mono object. Something like this error is used in artfacting. The atari hires modes (2 by text modes and 1 by bitmap) will show this problem. the 8bit colour clock has 2 pixels to one clock pulse in hi res 320X192 think of the whole width of the screen being divided by2 Each pixel pair is used to give the affect. If the first pixel is on and the second is off, a colour is displayed, if the 1st pixel is off and the second is on, a different colour is displayed, if both are on, the actual foreground colour is displayed. The colour displayed depends a lot on the tv/monintor used and if it supports artfacting. The text modes are mostly ok because the character map has all characters as double bit wide. As for why? maybe it was an easier port from the apple to the atari? extra colours in a hires mode?? James

if you are running the emulator atariwin++, there is a H: device James

Colour artfacting is used to produce the colours you see on NTSC screens. I am sure there are references on the net somewhere on how it works. Artfacting doesn't work very well or not at all on PAL, at least I never could, just yucky shades of blue-grey that has very defined vertical lines. There are a couple of hacked versions of loderunner that changed the display mode to hi res colour mode, It looks very much better on Pal screens, tho some parts don't quite line up. I must dig them up. There at least a couple of other games that use colour artfacting. James

The creators have replicated the problem I found and are at this moment tracking down the bug. It only shows it self when going over every 32meg boundary on the USB stick. How many single density floppies can you fit into 32meg? I calculate 364. or 182 double density floppy images. That is a lot of data. Otherwise it works well. James

Thanks for the info Thomas! I have tried out DOS 2.XL but it seems to lock up after a while. The OS sources to Atari++ look interesting.. I wonder if the disk handler code could be turned into a loadable DOS instead of the OS. I am still on the search for a DOS with a low MEMLO like around $700. Can SpartaDOS X be loaded from disk instead of from Cart? $700 is the lowest mem address available after the OS takes it's share. Some ram needs to be used for dos handler table etc. as far as I know, either spatados 2.3 or X has the lowest lomem. unless someone is willing to write one, that is the best you are going to get. James

Here is an interesting artical on toms hardware. http://www.tomsgames.com/us/2008/03/05/biggestdisasters_et/ James

That is very kind of you, but not the best option. It would be nice to have that tool on Mac, and even on Linux. But I would prefer a SIO2USB that simply accepts all kind of atr's around. When I'm using a certain -preferred - cross assembler which creates ATR's that are not compatible with SIO2USB I have to use that tool EVERY time I compile and try my program on the Atari. And yes... they are right... it would be better there are only 'valid header' ATR's around, but come on... if APE and Sio2SD and Sio2IDE are able to handle all ATR's... SIO2USB should be too. By the way I found a few other problems with SIO2USB... and now I really doubt if their opinion about 'valid atr headers' is the right one but thanks for your idea. Marius I'm curious about this -- what kind of ATR headers exist? (How do they differ one to the other?) What does your incompatible header and ATR look like -- can you post one? IIRC, there are "short" ATR's, there are ATR's that some versions of APE gave authenticity warnings about, there are protected ATR's (ATX's?) that indicate they have protection in them. Are there others? Is a "valid header" one that conforms exactly to the original SIO2PC specification? As I said, I'm just curious, because this is an interesting issue, and I haven't seen this problem with my SIO2SD. -Larry I would like to know as well

I have discovered more which is a very serious problem. Any write to an ATR image gfrom the atari to the SIO2USB that goes over sector 56636 on the usb stick will overwrite the boot sector and start writing over the 1st fat The sector size is 512 bytes on the stick so the first 32meg worth of atrs is ok. That is a lot of floppy images.......... James

Sorry for the confusion and thanks Warerat for clearing that up. Yeh, in my tinkering with eprom burners I need to pick up a 8-bit Atari cart for this purpose. Be interesting to see what it says about a stock Atari 800 and a Atari 800 with XE mod. That external device is rather interesting, it has an SIO plug, 4 joystick ports and 2 power connectors. Looks like it could test everything including power used. I have one here but have never fired it up so don't know if it works or not James

My first thought was Devil. James

A proper PAL conversion would require both ANTIC and GTIA to be PAL versions. An extra chip is mounted in the vacant spot on the motherboard. an extra crystal is also mounted with it's associated components (GTIA PAL colour crystal). the main crystal would need to be changed for a slightly slower one and finally the tv modulator is swaped for a PAL one. The os rom is I believe the same regardless. that covers the XL and XE. the 400/800 is different. The processor board would need to be swapped, the main crystal also changed, an inductor on the motherboard changed and also the modulator. James

I have discovered that a couple of my hard drive images that i placed on sio2usb stick from the pc are not what they should be when read by the sio2usb interface. a whole block of approx $1300 sectors of one image appears in another image. it is fine if the files are created and never removed or moved from the stick using sio2USB but copies put onto pc for backup will be corrupted. Not all files will be affected. only those that cross particular boundary's. I have emailed Thomas Grasel about my findings and the boundary's that i have discovered so far. The first couple of hundred of floppy images should be ok how ever. James

After having a look and a play with my SDX cart, It looks possiable to fit a 32 pin rom chip in the shells with no mods. I simply moved the rom up 2 pins and had a look. The resr should be the same as the intSDX instructions except pin 8 on the intSDX GAL is pin 13 on the original SDX GAL. to make life easy, a track would need to be cut instead of lifting a pin up. Now to get the rom and burn one if my super e burner will do it. James

The only easy way is to get an axlon compatible ram board. this usually has 256k of ram on it that is bank switched into the $4000,$7FFF area just like the XL-XE ram upgrade, but unlike the XL, the resister is usually at $CFFF. There is a 32K ram board available but the factory limit for the 800 is 48K of ram. Getting 64K just like the XL is going to be much more difficult. There was at least one upgrade around that would give 64K but the OS was a modified rev B. James

Get It Right was a great program. Saved me hours of debugging Antic mag typo was a bad error checker I once typed in a game that failed the typo check. Many times I went over the listing trying to find what was wrong. years latter i finally found the problem. I had a variable NO or something like that that should have been N0. Typo just had a group of lines that equaled a total and the variable list had to match else the lines total was out as well. Once the wrong variable name was found and fixed, the program had to be listed out to disk or tape, then entered back in and typo ran again. Way back then, only had a tape drive................................. Typo II was very much better and the same as ANALOG mags error checker. James

I think the gal used for the intSDX is functionally the same as the original because I believe that the original rom can be used with this little kit. only the pins are programmed different. Who does the intsdx gal? not many people would have a programmer for it. James

can this be used for the original SDX cart? James Not in its present form. The SDX requires a 27512 EPROM (64k bytes) to hold versions 4.20 and 4.21. These newer version of SDX require a 27C010 size EPROM (128k bytes). I haven't seen any info on if the SDX can be modified to support a 27C010 size chip. So far only alternative flash carts for the 8bit and a internal SDX cart seem to be the only options for this. I would prefer to modify my SDX cart. Just have to look at this and the intSDX modifications to see if they can be applied to the SDX cart. Does anyone know if the GAL code that is provided for the intSDX is a recreation of the programming code used for the programmable logic chip in the SDX cart? It would be nice to populate a few bare SDX cart boards that I have. By the way if anyone is interested in scanned images of these boards let me know. Regards, Glenn It looks like it may be possible. instead of pin 8 on the GAL, it is pin 13. biggest problem would be getting the rom to fit in the shell. the rom may be a couple of mm to long. james

can this be used for the original SDX cart? James

I wounder if that chip is static ram? if so, that switch would on the R/W line to enable/disable it. ie use a program to write to that cart then flip the switch to make it read only. Just a thought. James

I may have come with the instructions for the 800 for all I know. James

well, you could plug it in but it won't work. it shouldn't damage the computer how ever. the ram in the 400 and the 800 need +12V, +5V and -5V to work. all of which is derived from the 9V ac. james

got it. thank you. so far, the decoders are working ok. looking through the rom , the id bytes have bit 3 set when it should be clear, yet there are zero's. i grabbed a image of the rom and those same bytes are ok. hmmmmmmmmmm. james

does anyone have one? I have pulled out mine only to find it don't work. Somewhere in the front end ? computer end isn't going. ie selecting the rom and harware registers. james