The Plus D Corner, Part 1

The Plus D Corner, Part 1

Hello everyone! With these lines, I will try to start a series about the Plus D. Since writing is always a lot of work, I will send these contributions to both clubs (Profi-Club and User-Club). I hope that EBI and WO will support me creatively. That means, perhaps a few screens where appropriate or similar (I will send the texts in Wordmaster format). (Tasword would be preferred by me - note from LCD).

Much more, however, I hope that I will also read contributions from other club members in this "Plus D Corner". After all, I don't have to do everything alone, do I? My writing will essentially refer to the general and simple things about the Plus D. I lack the knowledge for the finer points. Perhaps someone can contribute something here. Miles Kinloch has already brought some great things in the past. Another possibility would be test reports on special Plus D programs. You see, there is enough to do! Don't disappoint me!

One more thing: Those of you who (like me) are in both clubs might forgive me if you now have duplicate contributions in your issues. But what should I say? I am in the same boat. Plus, I wrote the stuff myself! I hope for your understanding.

But now, enough "babbling":

THE PLUS-D INTERFACE

Under this title, I already wrote a description of the Plus D in issue 5.91 (Profi Club). Well, a lot has happened since that time. Some are new here in the club, others were not interested in the Plus D back then but might want to get one right now. The Plus D was not very widespread in 1991. Out of ignorance, I also wrote some nonsense back then. No big deal. I can make up for it here:

Plus D, what is that anyway? Well, primarily a disk interface which makes it possible to connect disk drives to our Spectrum. In addition, there is also a printer interface. The Plus D was developed at that time by the company Miles Gordon Technology. The same applies to the Disciple Interface, the predecessor of the Plus D. I don't want to go into the Disciple here; it suffices to know that both are compatible with each other (disk format). Disciple disks can therefore be read on the Plus D and vice versa.

The aforementioned company, which by the way also developed the SAM, has not existed for a long time. As far as I know, however, the Plus D is still distributed via the company Datel Electronics Limited. In any case, I received a +D there in June 1993. Who knows more about this? Here in Germany, it might be easier via SINTECH. In any case, the Plus D is currently still being offered there. (Sorry, you unfortunately can no longer get the +D from Datel, according to FPD, but I place all my hopes in the improved +D, which is being developed in Germany, not to forget the DX1. - note from LCD).

Below I will give a small insight into the possibilities of the Plus D. My description is by no means complete and I only describe standard functions. With other operating systems or special additional programs, it is, for example, possible to format disks with more directory entries or also to display a better table of contents. But all that would go beyond the scope of this article and should be covered in later contributions. In any case, I have firmly resolved to do so.

The Plus D is a very compact interface which is plugged into the Expansion I/O. Anyone who has a +2A, +2B, or a +3 should definitely specify this when ordering. An intermediate connector (FIXIT) is then supplied. The Expansion I/O is indeed different on these devices (thanks to Amstrad) than on the old Spectrums. You do not pay an extra charge for this intermediate connector. Even if you already have a FIXIT or because you have an old Specci and therefore don't need one, there is actually nothing to be said against ordering this version in any case. A FIXIT costs about 25 DM individually and not everyone is a tinkerer to build it themselves. Perhaps a +2A will come into the house after all, or a friend is looking for such a thing. A special +D for the aforementioned Speccis does not exist!

The +D has a Shugart 400 connection. As a result, almost all common drives can be connected. Nowadays, however, only 3 1/2" drives are sensible and recommended. HD drives also work, which of course does not mean that you can format the disks higher than with DD. One or two drives can be connected. It should be noted that every drive needs its own power supply (power supply unit)! The power supply is therefore NOT provided via the Spectrum! It is easiest to order a complete system with drives, power supplies, and cables. Don't forget the printer cable!

I don't have to say explicitly that the manual is written in English, do I?

The disks are usually formatted to 780 KB. Actually, it is 800 KB, but 20 KB are reserved for the directory, i.e., the disk table of contents. The directory allows up to 80 entries, so you can save up to 80 individual files. That is quite a lot by Spectrum standards.

The setup program for the operating system and the printer is supplied on cassette. In the setup program, a few questions are asked about the drives and the connected printer. Anyone who cannot cope with this should first adopt the standard entries of the setup program. This applies in particular to the printer settings!

After all settings have been made, the operating system and, if you want, the setup program are saved on a disk. After switching on the Spectrum, the operating system (G-DOS) must be loaded from the disk with RUN and ENTER. Only then is the system ready for operation. When switching the Spectrum on or off, there must be no disk in the drive! This actually applies to all Spectrum disk systems and, above all, to the Microdrive! The system file is retained after a RESET on the Spectrum. The Plus D has its own RAM. However, anyone who only has an old rubber-key Spectrum is out of luck. Unplug and everything is gone! So, it is best to install a reset button subsequently. Otherwise, it becomes annoying.

Now you can get started with disk management. At this point, I could describe the individual special disk commands, but that would certainly go too far. In any case, the syntax is much simpler than with the Microdrive. Keyword Microdrive: The Plus D also understands the Microdrive syntax (however, only in BASIC!). Thus, existing BASIC programs do not need to be adjusted.

A special feature of the Plus D is the Snapshot Button. With this button, you can "freeze" programs and save them to disk or print out the current screen. Anyone who has a Multiface knows what I mean. It works quite similarly there. Anyone who is switching from cassette to disk now certainly wants to "transfer" their software from cassette to disk. However, not all programs can be "snapped," and for multi-part programs with loaders, it is basically useless anyway. In the meantime, there are special Plus D versions of (almost) all programs. Even 128K games with loaders. Here, the advantages of a disk system become properly clear for the first time. The annoying searching on the cassette is eliminated. Not to mention the significantly higher loading speed.

Snapshot files are therefore actually superfluous and also quite frowned upon in the scene. However, the snap has two decisive advantages: Firstly, games, for example, can be frozen and saved. You can load them again very quickly the next day and continue playing. Or you can quickly save the current status to disk while programming without first having to enter a laborious SAVE command with a filename. The second advantage lies in the clearer catalog. Only one entry is required for the SNAP. Most programs, however, consist of several parts (BASIC loader, title screen, code file, etc.). That sometimes leads to quite a mess on the disk. It just depends on what you do with your Spectrum. For those who work with DTP, for example, snapshots are hardly interesting. However, for those who play their 48K games every day, snaps are actually ideal. Although SNAPS are always 48 KB or 128 KB in size, they are usually loaded faster than multi-part programs. That is simply because the disk drive does not have to move back and forth on the disk as much to look for and load individual files.

Phew, that was a long explanation on the subject of the snapshot button. Here again are the possibilities on the Spectrum keyboard after pressing the snapshot button:

Key 1: 32 Column Screen Dump (print screen small)
Key 2: Large Size Printer Dump (large printout)
Key 3: Screen Save (save current screen)
Key 4: Save 48 K program
Key 5: Save 128 K program
Key X: return to program

With CAPS SHIFT and the corresponding number key (3, 4, or 5), you can save to the second drive. After executing the selected function, the Plus D jumps back to the program. Anyone who has only accidentally pressed the SNAP returns with "X" without activating one of the five functions mentioned.

Snap Shot files cannot be copied with the "G-DOS" operating system. This is intended to prevent excessive piracy. The whole thing is no longer quite up to date these days. As I said, snaps are (like Multiface files) quite frowned upon, and "normal" files can of course be copied. Anyone who absolutely wants to copy snaps: There is special software that also makes this possible. How did it go again? Nothing is impossible, ...oh, Plus D!

So folks, enough snapped. Let's get to the printer connection: Centronics Parallel is supported, i.e., printers like the ones you can buy everywhere. A "Standard BBC 26 Way" printer cable is needed, whatever that may be. In any case, such a cable is available through our special dealers, e.g., at Indug (for 8 pounds). Possibly also at Sintech or Uffenkamp. The Plus D is compatible with the Epson FX80 standard. With most printers...

...printers there shouldn't be any problems. If there are, you have the option to make changes via the Setup program. But this requires good knowledge in the "printers" field and, above all, a good printer manual. That cannot be taken for granted. For example, I have never managed to print a large graphic directly via the Plus D! And that despite having two different EPSON printers! Yet the Plus D even supports the EPSON ESC code for BITIMAGE GRAPHICS. Maybe someone could write an article on this topic, I would appreciate that very much! That really is a science in itself. (I always write my own printer programs, it is better than trusting the +D. - Note by LCD).*

As mentioned above, it is possible to print via the Snap button or directly from BASIC:

• LLIST (like LIST, but redirected to the printer)
• LPRINT (like PRINT, but to the printer)
• CAT #3,1 (floppy disk directory to the printer)
• SAVE SCREEN$ 1 or SAVE SCREEN$ (small SCREEN printout)
• SAVE SCREEN$ 2 (large SCREEN printout)

Many programs (word processing, graphics software, etc.) support the Plus D printer interface. Instead of Plus D, DISCIPLE can also be selected. As already mentioned, special Plus D / Disciple versions exist for a great many programs. However, this topic is worth a separate article.

I could only give a brief outline here of everything you can do with the Plus D. Nevertheless, I hope I can get some of you enthusiastic about the Plus D with this. It is definitely worth the money and by now also widespread, so you don't end up with an outsider system. In addition, it is very fast. If you previously worked with Microdrive or even just cassette tape, you'll be thrilled anyway!

Well, that should be all for now. And next time, but on April 1st at the latest, I'll explain to you how to connect a 1-gigabyte hard drive to the Plus D. Bye!

Guido Schell in Autumn 1995.
My address: Guido Schell, Auf dem Stocke 37, 32 584 Löhne.
Telefon: 05732 / 8769.

Editor's Note:

I have to agree with Guido 99%: the +D is a really great thing, if it weren't for the problem with cross-linked files, or that some programs don't want to run with +D at all (3D Labyrinth by Fuxoft and several others). With the Disciple, things look better, not least because of the INHIBIT button, which makes the system invisible; the drawback of the Disciple is the quite high heat generation of the internal voltage regulator. I could also write a lot more about it, but Guido has already taken most of the work off my hands, D