sup8pdct

I have had my Indus since 1984 (I think) and while it is built like a tank and a very nice drive, it is nowhere near as versatile as a Happy 1050 or USD 1050... at least not to me. It's a wounder that noone has written a software add in for the indus to make it work like a USD drive instead of syncromesh. also to make it act like an archiver. With the ramcharger and a small hardware mod, it could be a bit writer as well. be able to copy anything then James

Nothing is inverted in this drive. AFAIK, the only drive I've seen with the inverted FDC was the 810.. I don't know much about the Indus, but AFAIK no drive inverts the data on the SIO bus (if you mean literally on the bus). What all drives do, is to invert the data on the disk. The reason is, as I've read, a bug in the original 810 firmware. The 810 uses an FDC with an inverted data bus, so everything sent to the FDC (including both data and commands) must be inverted. It seems they inverted it twice though, once when receiving/transferring the data from/to the computer, and once again when transferring from/to the FDC. The net effect was that the data was written inverted on the disk. The bug was harmless, because it was performed both when reading and when writing. Disregarding if the history is true or not, the fact is that for compatibility reasons, all Atari drives, including third party ones, write the data inverted on the disk sectors. As soon as I read this, I thought to my self "Yea Right". I then decided to check. I did 15 years ago dissemble the USD rom and put a lot of labels on things that I had worked out, not by any means complete, but enough to work out what most bits do. I discovered that what you say is true. Any read or write to the floppy disk data sectors has a EOR $FF to invert the data. I am trying to work my way through the Indus rom. boy is it hard but have found a few bits and the hardware registers so that is a start. Have also done the XF551, but it is much harder to work out..... James

I got an "error in read... Aborted" message. Oh, well. My problem is getting access to one... Trouble with dos Rpm checkers is that need to be able to read a sector with out errors to work..... Also if they don't take into account the Ntsc Pal difference like some early ones do. James

There are 2 adjustments on the 400/800. The one accessible from the bottom of the case is to do with the rf modulator, something to do with mixing or something. That one, you MUST use a plastic adjust tool The colour adjust pot is from the back. looking from the back, on the lefthand side of the cooling grills near the top, you should be able to see a hole through the shielding behind the plastic grill. That is the colour adjust pot. give it very small tweaks. James

what about when you want mac/65 or basic XE? James

How is this going? any more updates or work? Would it b e possiable to get the source? The z80 is very hard compared to the 6502.. James

Its connected to Pin 39 of Sally. The system does not freeze when booting with BB connected, $0247 is $00. Too bad i don't have scope nor logic probe. Maybe it is time to get your self one:) My logic probe is part of my multimeter. There was a mod for the PHi signal sent to the parallel bus. It involved using O0 and O1 or something like that, and a spare Gate. It stablised the PHi, made it stronger and made it happen slightly earlier. maybe this will fix the problems. I have had it time and again when checking things like this, it is easy to miss a small detail. James

only thing I can think of now is you may have a week cpu. the ones made in mexico I believe are the ones that are not real good. Do you have a logic probe? I do most of my trouble shooting with one of these. James

But with no luck again. The 1200XL runs as usual, not recognizing the BB at all. It won't either boot from the (already configured!) Harddisk nor bring up the BB menu. When doing my Google search, i found this text on the net: So, that guy ran into same situation as me. I'd really love to get that BB running, because the 1200XL board i work on is that one in my 1250XLD, the 1450XLD remake. A Floppy on PBI plus a SCSI HD inside would make my remake a bit closer to what Atari wanted the 1450XLD to become. The Flagship of the XL line. Is there someone who can give me some hints or, even better, did solve the same situation? Thanks for reading, Beetle have you checked the external select line (pin 2) on the pbi and it does do what it is supposed to? (it disables ram access regardless of address) another thing to check is all the address lines are the right way round. also the datalines. both BB and MIO have there own decoding of the address lines for registers etc. One trick is to continuity test the 1200xl cart port and the one on the BB pin for pin. There will be a couple of signals not present but it will test the data and most address lines at least. James From memory, both have MPD and external select line connected on the device.

the chip is a masked rom or a prom. A prom is a programmable read only memory ie program once . As for the wire jumper, it changes the action of the power switch around. Why? proberly to match other devices. Also note the circuit board is different between the 2 drives. James

Thanks, that's a nice site and great info! Now if someone could just give me the steady hands of a 30-year old! -Larry Don't let age discourage!!! If I can do this at 46, you have it made!!! Scary s**t though!!! I wish my eyes were 10 years younger. cannot see real close any more, making things harder............... James

Nice Work. I always wondered what they did differently. That's great info. I have always wanted to know since the late 80's when I saw the first XF with this problem. I also had to alert Bob Puff about it as well because his first version of the duel drive upgrade wouldn't work on PAL computers. The mod that bob wooly did also had to be changed as well. Now to make the listing readable with data statements (how ever that is done) and comments provided i can make sense of it. James

Have finally dissembled the rom code for the 8040 processor in the xf551 Have done both the 1st version (as far as i know) that would only work on NTSC atari's and the 2nd version that would work on all atari's This is 1st version: 0250: 00 NOP 0251: 00 NOP 0252: 00 NOP 0253: 00 NOP 0254: 00 NOP etc this is 2nd version: 0250: 44 EE JMP 2EE 0252: 00 NOP 0253: 00 NOP 0254: 00 NOP extra code in here 02EE: 44 53 JMP 253 The 8040 has it's jump instruction set so the lowest 3 bits of the instruction is the high order address and the 2nd byte as the low order address. each jmp instruction is 2 bytes and takes 2 cycles to complete. each nop is 1 cycle. For the cycle counters out there, you can see 1 extra cycle is added to fix the sio speed. the 8040 must bitbang each byte. Not sure if above code is for send or receive but both are same in regards to cycles counted. Extra code is also added to receive the command frame but it done in a different way. James

Hey Steve, Thank you for your reply. The problem is, as i've stated in my previous message, my 800XL doesn't have a FREDDIE chip. Or at least i think it doesn't. Couldn't find U6... I don't know what i should do with these signals in the Satantronic's schematics. I've read somewhere in the Internet, they demoed this expansion (back then) in some meeting and there were 2 versions, one for Freddie equiped machines, and another for machines with no Freddie chip. But in their website there's only the Freddie version of the schematics... If someone could provide me with some info on this matter, i'll very much apreciate this. Thanks! On the 800XL, there are no FAx signals, even if the XL has a freddie chip. On the XL freddie, FA14 and FA15 are A14 and A15. The FAx signals are unique to the 130XE. They come from a small PAL chip that handles all the bank switching and are modified A14 and A15. Modified only when extra memory is enabled (either cpu or antic) and which bank is selected. James

I personally have had 3 connected together. SDX, R-Time 8 and my special oss cart with all 4 oss languages in it. I also made a small piece of folded metal to hold them straight. one problem with a multi expansion box is the pass through carts, namely SDX, the express cart and the windows cart thingy. they need to disable access to the cart in the pass through connector. A games only one should be possible tho James

Just be careful with drives meant for Twister cables. the 4 DS pins have slightly different functions. the more modern the drive, the less likely it will have jumpers to set the drive to normal operation. To get a twister only drive to work as a normal drive, some work would be required, like cutting tracks. However, I doubt this would be your problem. James

As far as I know, The last starfighter game was to complement the movie but for some reason, atari never released it, Maybe because the movie wasn't a very big hit, but it got out through what ever channels were around at the time. A couple of years latter, atari renamed it to starraiders 2 and added base stations to re fuel and other minor changes. Energy was only available when ya flew to the sun in the original version. that is still there in SR2 tho it happens a lot quicker. I personally prefer the original because I played it a lot before SR2 came about. James

Superdos 5.1 is menu driven just like dos 2.X. if you have an xl/xe with 64K or more, the menu is stored under the os rom. it also doesn't destory the contents of ram when the menu system is tansfered. it will support 256K ram for use as a ramdisk. There is an AUX.sys for extra stuff like extra buffers etc and to write a boot game loader. Sbas.sys is renamed to autorun.sys and any locked basic files will appear in a menustyle to load and run. there are instructions for superdos here http://ape.dyndns.org:8083/BRADFORD/ I would be the default owner of superdos but it is in the public domain. James

That was my first thought as well, but when I started looking at how it was wired that seemed very unlikely. Most of the circuit definitely takes all its power from the SIO port. I'm guessing it hooked up to some kind of circuit with a switch or a relay possibly built into the equipment it was hooked up to. Most likely a modem or dumb terminal of some kind. Yes please, only if it isn't going to be too much trouble. No real trouble, except for the closeups. I had to retake those several times before they were usable. Those were a real pain as it would either overexpose the flash or just not want to focus that close. The two diodes, I can't make out the part number without removing them. I think they may be low value zeners as on both of them I got voltage drops of 0.7V forward biased and reverse voltage drops of 2.7V on one and 2.36V on the other. So they may be 2.5V zeners. Definitely silicon diodes of some sort. The ICs are MC1489N (that's the marked package) and the unmarked package is probably a 74LS126. At least it looked like it was one as far as I had gotten tracing out the circuits myself. And those are the two used in the Megaterm interface that was referenced earlier. This circuit is very similar to that one. If you do up a schematic I'd like to see it myself. Hopefully you can make heads or tails of it. Most of it makes sense to me, but not all of it. But then, when it comes to electronics I'm more of a repair than a design person. There's definitely some tricky klugery going on here that someone more designed oriented would understand that I don't. =^.^=;; Have had a quick look and it appears the 2nd chip is a mc1488 rs232 driver. it requires both a positive and negative voltage of around 12V which would be supplied from the same place as the rs232 cable is plugged into. so it isn't anything like the rverter or megaterm interface. Looking at the data sheet for the 1488 that actually makes some sense to me. Since even though the Atari SIO port could provide the Vcc+ from its +12V line it wouldn't be able to supply the Vcc- the 1488 needs. So an external power supply would required for the driver IC. But what about those two diodes then? Like I said, they look to be 2.5V zeners by the voltage drops I got across them. Interesting... BobKat judging by how they are connected, I would say they are protection diodes. the voltage across them would either be in the chip or maybe the caps. James

That was my first thought as well, but when I started looking at how it was wired that seemed very unlikely. Most of the circuit definitely takes all its power from the SIO port. I'm guessing it hooked up to some kind of circuit with a switch or a relay possibly built into the equipment it was hooked up to. Most likely a modem or dumb terminal of some kind. Anyway, for the insanely curious.... =^.^= If any of you really want to mess with it and trace out the circuit I'd be more than happy to post hi-res pictures of the device inside & out. I'd kind of like to know for sure myself, but I'm not gonna spend a bunch of time on it. So, let me know if you want me to post those pix and I'll try to get them up within 24 hours of hearing something. Yes please, only if it isn't going to be too much trouble. No real trouble, except for the closeups. I had to retake those several times before they were usable. Those were a real pain as it would either overexpose the flash or just not want to focus that close. Anyway, the camera had a lot of trouble with those and I sort of gave up on a good closeup of the serial port wiring. Only pins 2 & 3 are actually used and 7 is ground. The two electrolytics are both 100uF 25VDC. The two diodes, I can't make out the part number without removing them. I think they may be low value zeners as on both of them I got voltage drops of 0.7V forward biased and reverse voltage drops of 2.7V on one and 2.36V on the other. So they may be 2.5V zeners. Definitely silicon diodes of some sort. The ICs are MC1489N (that's the marked package) and the unmarked package is probably a 74LS126. At least it looked like it was one as far as I had gotten tracing out the circuits myself. And those are the two used in the Megaterm interface that was referenced earlier. This circuit is very similar to that one. If you do up a schematic I'd like to see it myself. Hopefully you can make heads or tails of it. Most of it makes sense to me, but not all of it. But then, when it comes to electronics I'm more of a repair than a design person. There's definitely some tricky klugery going on here that someone more designed oriented would understand that I don't. =^.^=;; Okay, here are the pix of the device. =^.^= Have had a quick look and it appears the 2nd chip is a mc1488 rs232 driver. it requires both a positive and negative voltage of around 12V which would be supplied from the same place as the rs232 cable is plugged into. so it isn't anything like the rverter or megaterm interface. James

That was my first thought as well, but when I started looking at how it was wired that seemed very unlikely. Most of the circuit definitely takes all its power from the SIO port. I'm guessing it hooked up to some kind of circuit with a switch or a relay possibly built into the equipment it was hooked up to. Most likely a modem or dumb terminal of some kind. Anyway, for the insanely curious.... =^.^= If any of you really want to mess with it and trace out the circuit I'd be more than happy to post hi-res pictures of the device inside & out. I'd kind of like to know for sure myself, but I'm not gonna spend a bunch of time on it. So, let me know if you want me to post those pix and I'll try to get them up within 24 hours of hearing something. later, BobKat Yes please, only if it isn't going to be too much trouble. James

That jack could be power for the unit. pics of both the top and bottom would be most helpfull. James

Hi James- I will look for this for you. I know that I used to have it, but I may have tossed the docs in a fit of "cleanup rage." I'm curious about your mention that it does not work with the XL OS. Do you have any idea what generally causes 800 carts not to work with the XL/XE OS? I'm sure there can be many things, but are there several that are quite common, especially for carts? -Larry In the case of edit 6502, I think it has something to do with the scrolling of the text on the screen. It is very quick. so I think an illegal call into the screen handler is used. as for other carts, it would be something similar, illegal calls into the os for what ever reason. James

does anyone have instructions for edit6502? I have an atr image of the program and placed it here as a download. It is an 8K cartridge and is loaded from dos ie a cart dump. it also needs os revB to run. the xl os won't work. It has a short routine at the front to move the screen down so it doesn't over write the cart. James EDIT6502.zip

If it is what I think it is, it will only do single and double density. the 1050 or enhanced density wasn't even around when this drive came out. I have no idea what it would be like with some protected game disks. Dos xl should be available at atarimania tho you will need to get it to a floppy somehow. if you have made a sio2pc interface, it would be easy. James