Chris Nixon gives the new Advanced Plus 2 ROM from Pres a trial spin

Since the rights to produce the Acorn Plus 1 were signed over to Pres - then ACP - way back in the mists of time, wonderful things have happened to Acorn's unwanted offspring. And now comes the arrival of the new AP2 ROM from Pres. It's a complete replacement for the Plus 1 ROM, and like all of Pres's other products, it's been well worth waiting for.

Those of you who have envied the BBC Master's enhanced Operating System need pine no more, for a good selection of its star commands - and some new ones - are now available for your Electron. These extra commands are made possible due to the fact that the original Plus 1 ROM uses only about 3K of the 8K ROM. This means that there were five whole kilobytes of space going to waste, and Pres has finally put it to good use.

A quick session with a screwdriver sees the AP2 firmly installed in your Plus 1. It sits in the same socket as the original ROM, with the half-moon notch facing in the same direction, towards the right.

When your system is bolted together again and the power turned on, typing *HELP +1 shows you just what's now under the bonnet of your Electron, and a pretty impressive list it is too.

You can now disable and re-enable any ROMs other than the default language or the Plus 1 ROM itself, using the Master-like *UNPLUG and *INSERT commands. Furthermore, the language to be selected upon the next CTRL-BREAK may be set using *LANG.

Typing *ROMS generates a list of all your ROMs, with an inverted U beside those which are currently unplugged. The default language as set by *LANG - normally BASIC - is indicated by an inverted asterisk.

The contents of any ROM can be saved to disc or tape, and loaded back into Sideways RAM, if present. What is most impressive about the AP2 is that it automatically copes with all of Pres's various Sideways RAM variations, including the AQR, ABR, ASR and the new AP7.

If you want to load a ROM image, you don't even need to specify which bank it's to go in, unless you want to - the AP2 will search the ROM sockets and prompt you when it finds a bank of RAM.

While on the subject of Sideways RAM, the AP2 includes some invaluable utilities normally available only in extra Service ROMs. *LOCK will write-protect the selected bank of Sideways RAM, while *UNLOCK performs the reverse process, allowing you to write information again.

And to save a bit of time, all RAM banks can be globally locked or unlocked, with *LROMS and *UROMS. Using either of these commands will produce a *ROMS display, where any unlocked bank will have an R shown beside it.

The AP2's repertoire of disc-handling commands should bring a tear of joy to those of you who are used to digging out the utility disc whenever a !BOOT file needs to be build, or a *DUMP is required.

Furthermore, there is a built-in ADFS formatter - *FORMAT - which detects whether you have ADFS version 1.00, and will accordingly generate the ZYSysHelp file. If you have a more up-to-date version, this file will be omitted from the formatted disc.

There's also the vital *VERIFY command which allows you to test the integrity of suspect discs, and there's even a version of the formatter which will automatically verify the disc after formatting, called *VFORMAT.

Even the humble *DUMP command is greatly enhanced over other versions. It automatically takes the current screen mode into account, and generates a dump which will always fill the display horizontally, but never exceed the current screen width - even in Modes 2 and 5!

Perhaps the most useful function as far as games players are concerned is the *KILL command. This completely disables the Plus 1, and even a CTRL-BREAK won't re-enable it.

I use *KILL all the time now, and find it invaluable when there are games to review which would normally crash due to the presence of the Plus 1.

Tape users aren't left out either. Included in AP2 is a software fix for the old tape loading problems when in high memory modes. Although it won't cure everything, you'll find tape loading in general to be more reliable with the AP2 present.

Overall, I was most impressed with the AP2. It now seems such an integral part of my Electron that I'm not sure what I'd do without it - I would hate to go back to manually disabling the Plus 1, for instance, and it's a matter of course now to *UNPLUG any ROMs which are interfering with a particular project.

As a complete upgrade for your Plus 1, £12.65 seems a small price to pay for what is much more than an ordinary third party ROM. The AP2 is the definitive Plus 1 ROM, and should have been written by Acorn itself in the first place.

Chris Nixon