The Demon is a devil of a modem, offering the sort of facilities you'd expect to pay a lot more for, says Kenn Garroch

There has been an awful lot of talk and rumout about what was originally known as the Unicom modem. At last it has arrived, under the name of the Demon. At £57.44, the little devil has controlling software, available for the BBC Micro only so far. That is an extra £23, bringing the total to £80.44. This means the Demon has more facilities than many devices costing twice the price.

The review version was set up to work with the BBC Micro, but since it operates through the RS423 port there is no reason why it could not be operated with other systems, with the appropriate software.

Most of the features are software selectable with only three buttons on the front to select originate/answer, baud rate scan auto/manual, and whether Bell or CCITT frequencies are to be used. The latter is probably the reason why this amazing gizmo still doesn't have the necessary little green sticker from the BABT.

The Demon has three wires coming out of the back: one for connection to a telephone socket; one to a 5-pin domino for the Beeb's RS423 socket; and the third is the power supply lead which connects to the mains supply via a 9V transformer. Demon seems to have saved its money on plugs and sockets. As none of these leads are detatchable from the mdoem, moving it around can result in a tangle of trailing wires.

Connecting up was easy apart from getting the RS423 plug into the BBC the right way round (due to the plug's dumb design). After inserting the ROM and turning everything on, a boot message tells us that the lucky old Beeb now has a Demon Zromm V.1.0. Sadly, *HELP Demon Zromm V.1.0 displays nothing about the star commands available.

One of the nice things about the system, as it stands, is the number of bits and pieces hidden inside the system for would-be hackers to find.

Work on the obvious sort of project - such as a Basic program to phone bulletin boards until it gets through - or, in fact, most others is easy. The facilities are instantly available with the star commands (see box).

The review system came with the customary photocopied manual that appeared to be incomplete. Not included were *HOST and *GET but Demon says these will be in the final version.

The manual has three sections: a simple overview of how to get started; a complete breakdown of the commands with examples for most; and a set of technical notes on control of the modem. This involves pulsing the RTS line of the RS232 port to control the baud rates and autodialling. There is also a section showing how to program the system from machine code.

The Demon modem is an excellent buy for the BBC. Versions for the Commodore 64, the Spectrum, and the Amstrad should be available soon. The only problems I had were generally caused by entering confusing commands which, perhaps, mucked up the timing. Fortunately, the system is flexible enough to get around almost any comms problem you might have.

Features 5/5
Documentation 3/5
Performance 4/5
Overall value 4/5

ANSWER ON/OFF
Turns the auto answer on or off

BAUD n
Sets the baud rates between 1200/75, 300/300 answer, 75/1200, and 300/300 originate

CARRIER
Waits 20 seconds for a carrier to appear; returns an error if it doesn't

CHAT
Enables a simple terminal mode

CLOSE
Closes all currently open files(e.g. CLOSE #0 from Basic)

DETECT ON/OFF
Enables the auto baud rate detect and select system; also controlled by switch on the front of the modem

DIAL number
Auto dials the specified telephone number

DLOAD name
Downloads a file from the modem and files it on the current filing system

FLOW ON/OFF
Select XON/OFF

GET
This resembles DLOAD but specifies the file type in the command i.e. GETCPM fnm

HOPPIT
Remove the Zromm from the Operating System to prevent clashes with other software

HOST
Gives the calling system total control over the BBC, i.e. similar to *FX 2,1 and *FX 3,1. The difference is that the Beeb retains its use of the keyboard as well - a powerful command

NOVEC
Disables all Zromm interrupts

OFF
Takes the modem off line

ON
Puts the modem on line

PRESTEL
Starts up the built-in Prestel software

PRETZEL
Dials 618 for connection to the London Prestel service

PSS
Auto dials the PSS computer in Slough, then puts the system into terminal mode

SEND
Resembles ULOAD closely except the format is specified in the command, i.e. SENDASC fname

STATUS
Returns the current status of the modem, whether on line, baud rate etc

TERMINAL No
Auto dials the number (No) and puts the Beeb into terminal mode. This is similar to CHAT mode but with a lot more facilities

TIMEOUT mins
Sets the amount of time before the modem automatically hangs up. Can be set between 0 and 255 mins

ULOAD name
Used to send a file to someone else. Three types of protocol are available; normal ASCII text, ASCII-HEX data and XMODEM binary data