| ★ APPLICATIONS ★ DIVERS ★ GRADUATE SOFTWARE CP/M ROM V1 ★ |
Graduate Software CP/M BOX (The Amstrad User) | GRADUATING WITH HONOURS (Computing with the Amstrad) |
DAVE DORN gets a taste for CP/M Plus on chips AS any CPC6128 owner will know, three operating systems are supplied with the machine. The one written by Locomotive software is built in, and comes into operation as soon as you switch on. The other two are CP/M 2.2 and CP/M Plus, which have to be loaded from disc. CP/M 2.2 is provided mainly for compatibility reasons because it is supplied with the DD1 disc drive for the CPC464, and used to be bundled with the CPC664. CP/M Plus is a later version of CP/M, and is more useful. It takes full advantage of the CPC6128's extra memory and has extra facilities. If you are a regular CP/M Plus user, loading it from disc is inconvenient in comparison to using an in-built operating system, more so if you often swap between Amsdos and CP/M. Now Graduate Software has solved that problem. On the basis that you can legally back up your CP/M discs for your own use, it provides a service where it transfers the system to a pair of rom chips. Each rom set is personalised with your name and serial number, and Graduate insists that you send in your system disc before performing the service, which of course is returned to you. As each of the eproms can hold 16k, and as c10cpm3.ems is roughly 24k long, the mathematicians among you will have noticed that there is 8k to spare. At least there would be, had Graduate not extended the system by providing what could best be described as CP/M RSXs and also building in some of the transient commands. But I'm ahead of myself -more of these later. The manual The 24-page A5 CP/M Loader Reference Manual is required reading before you even unpack the roms from their protective wrapping. Thankfully, it is indexed at both ends, and is logically set out, taking you from installation to use in orderly steps. Most of the rom functions are illustrated with sample files/command lines, and these examples are clear and easily understood. The first job is to install the roms in your rom board. Graduate suggests that it is preferable to have the first rom resident in a slot below the disc rom. CPC464 users without the Britannia rom board and ARCS rom have little choice in this matter, while CPC6128 owners will have to decide for themselves whether to follow this advice. I tried the two roms in a number of positions, both above and below rom 7, and had no problems initialising and using them. One pointer though: All roms have an orientation nick at one end to enable you to insert them correctly in the slots. Graduate's labels cover these nicks, but are printed with semicircles corresponding to them. You should be absolutely certain that you have correctly inserted the two roms before you power up, otherwise you run the risk of rendering your roms useless. And don't think that this is impossible to do. A very experienced user of my acquaintance managed to kill one of his roms in exactly this way, and had to seek a replacement from Graduate. (Don't you dare tell them who! - Ed.) On power-up your screen will look a little different from usual. The roms announce themselves by printing your name and changing the background colour to red, followed by the rest of the rom sign-on messages with the usual blue background. CP/M is called by either of the bar commands |EMS or |O, and takes you to the CPM Plus prompt at lightning speed. You will notice that the prompt is now a double-shafted arrow ( = >), indicating that the extra CP/M commands are available. Should you have a profile.sub file on disc in the drive, this will be executed as normal, making auto booting applications very simple. A word of caution: Some programs will behave erratically unless the profile.sub that calls them is altered to restore CP/M to normal without the extended commands. This is done by including the command CCP (for Console Command Processor). I found it easier to include this in all my profile.subs as the last command before the call to the application. Alternatively, the program you wish to run can be called from Amsdos by using either |EMS or |O followed by the program name. The program can be in either drive and is called by: |EMS,< d >: !< filename >!where < d > is the drive letter and < filename > is the program call. Note that the plings are required. Further extended and transient commands built-in include: |OP, which allows conditional entry into CP/M, and displays a menu of .com files. All you need to do is key the number of the .com file to be run, and the roms take care of the rest. Pressing Escape allows you to change the disc, while pressing it twice returns you to Basic. CKEY, NKEY, SKEY. These can replace the setkeys.com and associated keys. * files to allow you to define any key on the keyboard in control, normal, and shifted modes. This means that should you so desire, it is possible to do away with setkeys.com and save 2k of disc space. PALETTE replaces the CP/M transient of the same name, using the same parameters - another 1k of disc space saved. An associated command INK allows you to supply a pen number and colour required, much as in Basic. INVERSE is self explanatory: It allows printing in inverse characters. LANGUAGE replaces the transient program language.com, as does RENAME with its ordinary CP/M equivalent. There are more in the same vein. One major improvement over the CP/M Plus as supplied with the CPC is in the way that these transient commands work. In every case, Graduate has arranged matters so that if a parameter is expected with a command, and it is not present, CP/M will prompt for the necessary input. Users of Arnor's utility rom Utopia will know how easy extended Amsdos commands become when used in this fashion, and the same applies here. It becomes possible to include PALETTE in a profile.sub, and be prompted for the colours you wish to use. This is something that I particularly appreciate, as being colour blind certain colour combinations can be almost illegible to me while being perfect for most other people. In use I had a few reservations about CP/M on rom before the Graduate CP/M dropped through my letter box, mostly about transient commands and auto booting applications. After using the roms with just about everything CP/M that I have, my reservations have disappeared. One gripe I always had with CP/M was the incessant file shuffling that seemed to be necessary to achieve painless running of programs. Transferring the .ems file to a system format disc, and then copying files from a master disc on to the work disc, constructing a profile.sub, and then creating an Amsdos Basic program called disc.bas had become a necessary chore. As you can probably gather, disc.bas consists of one line: 10 |CPMWith Graduate CP/M Plus installed, I have no need to do anything other than back up the program and construct the relevant profile.sub. Using the in-built menu produced by |OP makes life simpler too, especially if, like me, you sometimes let your files get jumbled up and forget to label discs. The ability to redefine keys simply and quickly is also an unexpected bonus, the CP/M version being a little long winded, and, to me, less than mnemonic. Graduate has also included some Basic RSXs in a little corner of the roms, although they are likely to be of limited use. |VER or |CPMVER prints the version number of the roms to the screen, and |MYNAME outputs the registered user's name. Neither of these two commands are likely to change the face of computing as we know it, but |PASSWORD and its associated |PW might do a little to increase the security of your Basic programs if you don't want anyone else to use them. Each rom set has a unique password built in, which can be incorporated into Basic programs. If some unauthorised user is trying to gain access to a program so protected, he has but three attempts to get the password right before the program aborts. Using I PW at different points throughout the program causes an abort if the password? prompt has not been correctly answered earlier. I don't have a use for such refinements, being to programming what Mrs Thatcher is to Socialism, but they may be of use to you. No, it is the extensions that Graduate has incorporated into CP/M Plus and the vast increase in loading speed that make it so very useful. There are still little backwaters of the roms that I have yet to explore fully, but even so, I am loth to return them to their rightful owner. If you are a regular user of CP/M Plus, you will soon find Graduate's version indispensable. If you aren't, and you get the chance to see how much simpler these roms make using CP/M, I think you will soon be converted. My one reservation would be the price for the CPC owner without a rom board, particularly CPC464 owners. Combined Precision Components at present ask £16 for the CP/M Plus system discs - a fair price - but to pay £30-£40 for a rom board, and then £24.95 for the roms may not appeal to everyone. Having said that, I still consider Graduate CPM Plus to be so useful to the serious CP/M user as to be worth paying that bit extra. Well done Graduate - top of the class! CWTA |
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