80-Bus News

hardware description is short but with enough detail to allow the user to cope. The majority of the manual very adequately covers the software provided. One day Gemini will get round to employing someone who can wield a drawing pen, as once again, any illustrations in the manual have been composed using the printer and look tatty.

The software

There are three parts to the software. A demo with its source file for auto-answering, not very useful, but invaluable for those few who will go on to write proper answering software. The two main parts are GEMTERM a ‘comms’ program written for the card, and a suite of programs modified around Richard Beal’s DIAL program.

GEMTERM is a complete entity, being a terminal emulator with the ability to send and receive ASCII (not binary) files. All parameters needed by the MODEM and program can be set manually or from a library of parameters, items such as baud rate, the mode, the number to ring (if any), whether the loudspeaker should be on or off, the number of data bits to be used and the parity (if any). The first entry in a line of library data is a name, so GEMTERM can enter and dial the service required direct with no intervention by the user. Other parameters available from the command menu include memory save of incoming data, XON/​XOFF protocol select, printer echo, number of nulls to use after line feed, disconnect line, and many others. This is stand-alone software dedicated to the GM870 and it makes good use of all the features of the card, particularly the ability to select a service, set up the MODEM, dial the service and then let you get on with it. It works well, but being new and unfamiliar to me I had a problem remembering the commands at first. I particularly liked the library facility which saves all the hassle of remembering the MODEM parameters for a particular service and the telephone number. The snags, it can’t handle the 1200/75 Prestel service properly or the Viewdata compatible bulletin boards (these require interpretation of graphics symbols) , and it will only send or receive ASCIl files.

DIAL has been mentioned before. A similar idea to GEMTERM as far as the library goes, but otherwise, completely different. What DIAL does is to fetch an appropriate ‘comms’ program for the service required, set up the MODEM for that service, dial the number and wait for reply, and then jump straight into the ‘comms’ program. On exit, DIAL disconnects the line. DIAL may be patched for a number of different MODEMs, not only the GM870 and may be purchased as a separate entity if required.

DIAL always expects a second command parameter, if you don’t give one, it will prompt for one, so the command:

>Dial Target

would execute DIAL which goes to the library, looks up TARGET, then fetches UKM7, the appropriate ‘comms’ software, gets the MODEM parameters and sets them, dials the number, waits for a reply, and when a reply is received, jumps into UKM7. There are no terminal controls from DIAL itself, UKM7 is the terminal program and that does the business. This means the DIAL can be used with appropriate software for the service to be called, and two ‘comms’ programs are provided. Snags? None encountered but would be nice if it sent service ID’s instead of leaving this to the ‘comms’ program. But that perhaps would complicate matters somewhat. Another thought for DIAL would be an internal password, as it’s so easy to use, I caught my kids trying to raise the Titanic at 2p a frame on Prestel.

UKM7 is a public domain program and is a UK version of the original all bells and whistles American MODEM7. MODEM7 was very system dependent, and not really appropriate to UK use so David Back put it through a mincer and came up with UKM7, a version entirely suited to UK use. Richard Beal has removed the UART initialisation routines as the initialisation is carried out by DIAL, although the full source and documentation is supplied so UKM7 could be put back to its original state with no difficulty. This is a very powerful program, not only a terminal emulator, but it incorporates down load and up load of files (singly or in batches) in ASCII or binary mode, using both old and new versions of XMODEM binary self checking protocol. It also has the ability to trap all I/O and keep this on a separate file, so that mistakes or stuff arriving too fast to be read at the time can be analysed later. All clever stuff, and improving all the time (see below). Snags? Touchy about syntax and also seems to get it’s knickers in a twist when up-loading and down-loading in the wrong mode. It you’re going to use this one, take David Back’s name out of the sign-on before use. (The manual doesn’t mention this.)

The last program supplied is TERMB, a little terminal emulator with buffered I/O written up in 80BUS some time ago. Very fast and simple. Dead easy to use with no vices.

Not supplied on the disk is Pretzel2, Dave Ryder’s Prestel terminal emulation program available from Henry’s. The new version 3.0 is fully compatible with DIAL and may be directly used with the GM870. Works well.

In use

Couldn’t be simpler, I plugged it straight in and it all worked. Well I haven’t yet tried the auto-answer program. People tend to phone me, not the computer. Other than that, what can I say, it all worked!! All the software works and GEMTERM and DIAL libraries are easily set up. Pretzel2 worked, but two versions were required for use