About Scorpio incompatibility

Hello, All The Scorpio developers have always talked about 99% compatibility of their brainchild with branded Specky. This myth was dispelled after it was discovered that Programs that use access to the FD port do not work. Carefully studying computer operation and examining the td-dos ROM, another SMALL thing is discovered discrepancy with the spec's circuit design. We are talking about the magik button. Everyone knows that By pressing this button, a copy of the 48th memory is reset to the disk. What if the computer 128th? It turns out that in this case the entire 128th memory is reset, for with the exception of empty banks. To implement this operation, tr-dos ROM contains commands to access port #7FFD. But in Scorpio, when you turn on the tr-dos ROM, everything ports, except those needed to work with VG93, are disabled! Therefore on Scorpio can neither write 128th magik files nor load them.

Hello, Jukov Juk> Scorpio developers have always talked about 99% compatibility of theirs Juk> brainchild with branded Specky. This myth was dispelled after Juk> it turned out that Scorpio does not support programs that use access to Juk> port FD. Carefully studying the operation of the computer and examining the td-dos ROM Juk> another SMALL discrepancy with the specky circuitry is discovered. Juk> We are talking about the magik button. Everyone knows that by pressing this button Juk> a copy of the 48th memory is flushed to disk. What if the computer is 128th? Juk> It turns out that in this case the entire 128th memory is reset, for Juk> excluding empty banks. To implement this operation in the tr-dos ROM Juk> contains commands for accessing port #7FFD. But in Scorpio Juk> enabling tr-dos ROM, all ports except those needed to work with Juk> VG93, turning off! Therefore, you cannot write the 128th on Scorpio Juk> magik files, do not load them. Great, dude! And apparently I have some kind of leftism, and not Scorpio... That's all it is recorded, everything is loaded... Damn it, but it’s impossible!

Hello Shadow Maker Sha> Great, dude! And apparently I have some kind of leftism, and not Sha> Scorpio... Everything is recorded, everything is loaded... Damn it, but Sha> is not allowed! Got it, the misinformation didn't work. I am correcting the previous message.

Hello, Jukov Talk about the compatibility of ZS Scorpion with branded models, in terms of problems Beta Disk controller is not entirely correct. Because this controller is absolutely third-party in relation to branded models. Yes, and for compatibility (as on possibility of launching and correct operation of proprietary programs) Beta Disk in ZX Scorpion has a very indirect effect. Problems with flushing to disk using Magic could occur for another reason. And not only on ZS Scorpion, but on most clones without redone procedures initialization of Beta Disk and branded models even more so. Let me explain. The fact is that the branded Beta Disk Interface controllers did not have WD1793 (VG93) hardware reset is provided, during Reset itself computer. And the Reset button appeared only on the ZX Spectrum+. On ordinary (rubber) ZX Spectrum it simply wasn’t there and the computer needed to be reset disconnect from power. One way or another, there is a problem with the WD1793 initialization, Beta Disk developers Interface was solved by using the D2 bit of port #FF to reset the controller. But in order to WD1793, you need to perform a procedure from ROM TR-DOS, because only from there are the controller ports available. In addition, the developers code built into the ZX Spectrum 128 ROM, of course, they didn’t know anything about Beta Disk Interface from Technology Research. In fact, this led to the fact that after turning on the ZX Spectrum 128 withconnected Beta Disk Interface, the latter must be initialized by typing cherished RANDOMISE USR 15616 (15363). After performing a disk operation, you can was to return to BASIC or the computer, and then, loading from tape program press Magic. And everything was OK, or almost everything. But if, after turning on the power (the computer was in the ZX start menu Spectrum 128), launch Tape Loader and after loading from the tape, press Magic, then the chances of getting a damaged disc were high. Processing procedure for RST#66 in ROM TR-DOS did not imply waiting for the WD1793 to initialize, but installed D2 ports #FF in <1>. And then the memory began to be saved, as if the WD1793 was ready for work. The problem was solved simply: by connecting a hardware reset from the computer to the VG93, or by modifying the ROM initialization procedure when turned on (or processing RST#66 in TR-DOS ROM). How it was (or was not) implemented in ZS Scorpion those who understood its ROM know, but there was no hardware modification in it.

Hello Conan From personal experience - I once used the magic button, the discs did not deteriorate, 128k “threw off” correctly. A couple of times the “save” didn’t start, but it The solution was simple - press “magic” in a slightly different place in the program.

Hello Conan Con> ... The problem was solved simply: by connecting a hardware Reset from Con> computer to VG93, or by finalizing the ROM initialization procedure Con> when powering up (or processing RST#66 in TR-DOS ROM). How it was (or Con> was not) implemented in ZS Scorpion, those who dealt with it know Con> ROM, but there was no hardware modification in it. Scorpio doesn't really have a hard reset Beta Disk Interface, but after pressing the Reset button, the fast test of computer procedure is performed, which, among other things, and resets the controller programmatically before starting BASIC systems. Well, of course, I couldn’t help but have a question: how was it done in ZX-Next?

Hello, ewgeny7 ewg> The second feature is the “small” quantity by the standards of the same Pentagon ewg> cycles per frame I have always wondered why the Pentagon is taken as a standard? But how many cycles does a Pro have, for example? at ATM? The branded one has 128,+2,+3? It turns out that they all have this “flaw” because of the Pentagon.

Hello Conan Taking advantage of this thread, I want to say a few words about “non-standard” Scorpio. There were a lot of attacks on this computer. But, IMHO, it has only one drawback. This ports 7FFD and 1FFD. Since the second port can actually change the config computer, then the OUT (FD),A command can in some cases completely kill any good endeavors :) For the computer to work correctly, more than exact port indication. This was a major problem in the 90s. Judging by the latest programs, coders have finally left childhood, because on Scorp ALL programs are coming. And this feature of Scorpio can hardly even be called a disadvantage, because "recklessness" for the sake of saving two bytes is ... :( The second feature is the “small” by the standards of the same Pentagon, the number of cycles per frame. This has already been discussed on our forum, the reason is banal to the point of disgrace - Scorp has the most “correct” scanning of the TV signal, 312 lines (unlike from 320 at the Pentagon). These “missing” 8 lines precisely determine “lag” of Scorpio from models “sharp as diarrhea” (C) Shmatrix :) Not difficult to think that this, again, is a very controversial “disadvantage”. Try recording video from the Pentagon on a video camera. Most likely you will get a "hee-hee". Scorpio has there are no problems with this. This model has many more advantages than disadvantages. Scorp in conjunction with SMUK andProfPZU is not even a Spectrum, it’s just some kind of monster :) Everything is thought out, hard drive with TR-DOS floppy emulation, even user adjustable moving the mouse cursor (adjustable bitrate of mouse signals)! Choice of any possible operating mode VG73, sectors of any length, built-in monitor-debugger with the ability to Forth program its breakpoints and the corresponding event processing... The list is long. The only thing he doesn't have is Compared, for example, with ATM, these are additional graphics modes. More precisely, no in the “basic” model, a gadget called GMX (now handled by Spensor) gives in addition to additional memory of 2 megabytes there is also an additional video mode high resolution. Evil "Scorpio" Evgeniy :)

Hello Costa Cos> I always wondered why the Pentagon is taken as a standard? By the mid-90s, when the domestic demo-building industry was on its feet, the most the mass clones were the Pentagons and Scorpions. Of course, in each specific In this case, the reasons for writing demonstrations for certain temporary huts were individual, but counting cycles was easier for the Pentagon, because there was no braking (WAIT). And about the fact that the temporary buildings are very different from branded cars and simply television standard, no one really thought about it. Almost always connected according to RGB (which means we didn’t notice any deviations in the scans), but about the temporary Few knew branded cars. So it turned out that the Pentagon has gained popularity and overgrown with software for his non-standard temporary huts. It just so happened, because not always the best solution wins. Perhaps it was also influenced by the fact that, other things being equal, the Pentagon was somewhat cheaper, and you could buy it in the form of an empty board (and at the local radio market, rather than ordering by mail). And for beginner sceners (for example, schoolchildren or students), price was an important factor.