The Plus D Corner, Part 3
Dear Plus D friends! Today I want to introduce you to another (better) operating system for the Plus D: BETA DOS!
Some of you might perhaps remember my review in the Profi-Club magazine 1/94. I decided to present BETA DOS once again as part of the Plus D Corner. Firstly because it naturally fits in well here, and secondly because over time a few other things have come up that I would like to report on. Furthermore, members of the Spectrum User Club now also get to "enjoy" my article. So, reasons enough to keep reading (I hope).
BETA DOS was written in 1990 by Dr. Andrew J.A. Wright (BETASOFT). Who is "Andy" Wright? Well, many of you certainly know BETA BASIC. SAM users (do they read my Plus D Corner too?) have Andy to thank for the SAM ROM! MASTER DOS or MASTERBASIC should also be familiar to every SAM user. What kind of useless trivia am I rambling on about anyway—BETASOFT should really be known to each of you in some way, shouldn't it?
Now let's finally get down to the nitty-gritty:
CATALOGUE
The CAT 1 and CAT 2 commands are a bit more detailed. In addition to the free disk space, the number of used and free catalog entries (slots) is also displayed. A CAT 1 can look like this, for example:
- * MGT PLUS D DISC 1 CATALOGUE *
1 +SYS 2a 14 CDE 8192,6656
2 TEST 20 BAS
No. of Free K-Bytes = 763
2 File(s), 78 Free SlotsCAT can now also be used on its own and corresponds to the command CAT 1! or CAT 2!. If you only enter CAT, the last used drive will be accessed.
CAT, CAT 1!, and CAT 2! are much faster than in G+DOS. The catalogue is sorted alphabetically. The sorting can be disabled via a POKE command. Another POKE command allows you to define the number of columns in CAT (meaning the "simple" catalogue). That is, single, two, or three columns. More columns make no logical sense, unless you have loaded a different font with smaller characters or you redirect CAT to a printer.
FORMAT
Formatting can also be performed while a program is in the Spectrum's memory. With G+DOS that is a risk, because part of the memory gets overwritten with FORMAT information. BETA DOS uses only the remaining free memory for formatting. By the way, it does not matter where RAMTOP is set, the actual formatting time does not change. However, there should still be some space left in memory, otherwise you get the familiar error message "4 Out of memory".
Disks formatted with BETA DOS are about 10% faster than normal and can also be used with G+DOS. However, the catalog must then have the standard size of 80 files. And that brings us to the next special feature of BETA DOS:
You can specify the number of tracks used for the catalogue. That means you can, for instance, set up a catalog of 200 files! In that case, though, only 750 K-bytes are left free for data. Each catalogue track holds 20 file names and takes up 5 K-bytes of space on the disk. The minimum possible is the default 80 files (4 tracks, 20 K-bytes) and the maximum is 780 files (39 tracks, 195 K-bytes). With such a massive catalogue, only 605 K-bytes remain free. That means, if you want to fill the catalogue, the individual files cannot even be 1 K-byte in size! Is there any practical use for such a thing? Let me know! (Note by LCD: How about fonts? Compressed ones, even?)
SAVE file TO file
ALL files can be copied. That includes snapshots, etc. Unlike G+DOS, BETA DOS does not perform a NEW after copying. The file currently being copied is displayed on the monitor. All in all, a genuine improvement.
SAVE OVER
With SAVE OVER, files can be overwritten directly without the "Overwrite?" prompt and "(y/n)" query appearing. This has advantages, for example, when overwriting SCREEN$ files that you do not want to "damage", or when "reSAVING" multi-part programs.
LOAD @ / SAVE @
Multiple sectors can be read and written in a single pass. This is very fast. SECTOR LOAD / SAVE is also used in the backup program. See under "BACKUP UTILITY". Syntax:
LOAD @ drive,track,sector,address,number of sectors
The same applies to SAVE @. So in principle it is just like in G+DOS, only the number of sectors is appended.
SERIAL FILES / MOVE / RANDOM ACCESS FILES
I have never seriously dealt with these things, so I am not very familiar with them. The BETA DOS manual is very detailed here. But my English skills are unfortunately limited, so I cannot say anything about this. Besides, it is a very complex topic that would exceed the scope of this article.
KEYBOARD LOCK UP
Anyone who works a lot with the Plus D knows that every now and then, after disk access, the Spectrum keyboard locks up. With G+DOS, the only cure is a reset or clever tricks with a Multiface, etc. With BETA DOS the problem remains, but you can clear the error by pressing the snapshot button and the "0" (zero) key. (Note by LCD: I recommend M.K's SNAPOUT!)
BACKUP UTILITY
This is an additional program written entirely in BASIC. As the name suggests, it is a copier program for making disk copies. It always copies entire disks, meaning sectors rather than individual files. However, there is a special feature compared to other sector copy programs: only occupied sectors are copied! Naturally, this takes up much less time.
I already covered the BACKUP program and the topic of copying disks in the second part of this series. I won't repeat everything here. Below, however, is some supplementary information for +2A/B and +3 users:
The program also supports the 128K RAM DISC. This minimizes disk swapping—a huge advantage if you only have one drive. However, BACKUP cannot be used on the +2A/+2B in 128K mode (+3 DOS). The same applies to the +3. Anyone running a +D in 128K mode on a +3 knows that there are entirely different difficulties here. But that is another topic. Rewriting the program to use the Amstrad Speccy's special RAM DISC syntax (because of +3 DOS) doesn't help either. Instead of writing to the RAM DISC, the +2A/+2B tries to write to tape! Ridiculous! But I've noticed that in other experiments regardless of BETA DOS. The +2A/+2B with an attached +D simply refuses to work properly here. The problem has become widely known by now, but so far nobody has been able to tell me what causes it.
PEEKING and System Variables
You can peek into the +D ROM/RAM, and there are also a few new system variables. I don't want to go into detail here; that too would simply be too much.
SQUASH
With this utility you can compress SNAPS. The +D does not have enough memory to house SQUASH directly within BETA DOS. It is therefore a separate EXECUTE program loaded into the +D RAM. However, the sorted CAT and the new functions will no longer work. This means, for example, that BACKUP will no longer run. You can't have it all, after all. SQUASH can be very useful if, for instance, you like gaming and want to save your current game state in between. Or while programming, e.g. in assembler. Then you can quickly save the current state and reload it later (e.g. after a crash or if you've messed something up). Naturally, that is much faster than having to gather all the individual parts and reload everything from scratch.
How well it compresses depends, of course, on what is in the Spectrum's memory when taking the snapshot. The compression is generally immense, however. As a reminder: no matter how little is stored in Spectrum RAM, standard SNAPS always save the full 48K or 128K. Or to be more precise, 97 or 258 sectors. It makes sense, then, that when using SQUASH, more SNAPS fit onto a disk than usual, and because the files are shorter, the actual loading times are significantly reduced.
It should also be mentioned that you can only load "SQUASH SNAPS" if SQUASH was loaded beforehand. Normal SNAPS can be loaded in any case. Furthermore, compression can be turned off with POKE @127,0. This way, compressed SNAPS can be loaded and then saved again as normal SNAPS. With POKE @127,1, compression is switched back on.
RUN
Using RUN, the operating system can be reloaded. This makes it very easy to boot a different disk (possibly with an autoload file). With G+DOS, the old operating system must first be removed. A reset isn't enough (fortunately). Disk out, power off, power back on, disk back in, and then finally RUN. Rather cumbersome, isn't it? So, a genuine improvement. (Note by LCD: POKE @7652,0 is also enough to kill the system. You don't have to switch off the computer).
BUGS
As Andy Wright wrote to me, he personally only knows of one bug in BETA DOS: it is supposedly not possible to format a disk in drive 2 (FORMAT d2). On my setup, it works flawlessly! This may be due to the type of drive used.
That is by no means all, though! Probably the worst bug in BETA DOS is that specialized +D programs utilizing DOS from machine code do not run with BETA DOS! That includes, for example, Tasword 3, Tasword 128, Tasword PLUS 2, ORGANISER by Betterbytes, and THE COPIER. There are also several other quirks. However, rather than listing everything here, I would much rather point out a first-class PD program:
BETA DOS BUG FIX by Miles Kinloch !
Anyone using BETA DOS cannot get around this patch (I explained the term "patch" in part two of this series). With it, all programs run (at least whatever I have here). There is also a very useful additional command: with LOAD dn or SAVE dn (where n stands for the drive number, 1 or 2), I can switch the drive very easily. If, for instance, drive 1 is active and I want to load a program from drive 2 with LOAD P20, I normally have to enter CAT 2 or CAT 2! first, and then LOAD P20. With LOAD d2 and then LOAD P20, it is of course faster because CAT always takes some time
...needed. When entering the new command LOAD d1 or LOAD d2, virtually nothing happens. That the other drive is now active can be seen from the drive indicator LED (one turns on, the other off). My goodness, that certainly could have been explained more simply. In principle, the command is totally simple, but very useful indeed.
"BETA DOS BUG FIX" is available from any good PD service. Included is a text file by Miles (unfortunately only in English) describing the BETA DOS bugs. By the way, this is reprinted in the club magazine of the Spectrum Profi Club (issue 7.96). Maybe someone (who knows English better than I do) will take the trouble to translate this text into German!?
Now I would also like to note (it fits in so nicely here) that there are bugs in G+DOS as well. But for this too, there is a patch by Miles with an accompanying text file. I already described this briefly in Profi Club issue 6.94. Anyone who does not use BETA DOS should definitely get "G+DOS FIX". Also PD!
At this point: MANY THANKS, MILES!
TIPS
Finally, two important notes: unlike G+DOS, BETA DOS cannot be saved directly to disk using SAVE, but must be copied with the SAVE TO command. For example, like this: SAVE d1 "+sysBeta" TO d2.
To create the BETA DOS system file ("+sysBeta"), you need a G+DOS system file (e.g. "+SYS 2a"). This G+DOS system file must under no circumstances be "patched". So always use the original from the +D installation program!
ORDERING
So who is BETA DOS interesting for? Well, in the end everyone has to decide for themselves. I have described the main advantages of BETA DOS here. Everything else is really more for FREAKS and programmers. For the "normal" user, say for home use, G+DOS along with G+DOS FIX is actually sufficient.
I bought BETA DOS in November 1993 directly from Betasoft and I don't know if it is still available.
Back then it cost 9.95 pounds. It is best to send a Eurocheque for 10 pounds in advance (mark it with "Nur zur Verrechnung" / account payee only!). Additional money for postage is not required. I paid 1 pound extra back then and got it back with the delivery. Great service. There are no updates (or none anymore). As Andy wrote to me back then, he lost the source code!
In any case, I use Version 1.3 and I don't know if any older versions are in circulation at all. I received BETA DOS on a 3 1/2" disk.
Betasoft
24 Wyche Avenue
Kings Heath
Birmingham
B14 6LQ
Great Britain
I took the address from SUC-SESSION April 1996 (Spectrum User Club). In the July issue of SUC-SESSION, I now read that Betasoft has transferred the distribution of its programs to Format Publications. You can find the address on the back of SUC-SESSION or in the Profi Club magazine issue 7.96 on page 5 at the top. Behind Format Publications is, by the way, the British Spectrum and Sam Club INDUG, which also distributes the SAM for West Coast Computers.
Finally, an addendum to Part 2 of this series. A small mistake crept into the table: naturally, I tested the Beta-Dos Backup Utility in 48K and 128K mode. So change the column "TEST IN MODUS" in the row with "0.43" and "3 Swaps" from 48K to 128K! I wonder if anyone else noticed.
As always, I am happy to answer questions and receive feedback:
Guido Schell
Auf dem Stocke 37
D-32584 Löhne
Tel. 05732 8
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