Inter-Sheet is a high quality spreadsheet program, based on two ROMs totalling 24K, and is competitive with Viewsheet and Ultracalc 2 (see previous reviews in Vol. 3 No. 3 and Vol. 4 No. 11). It is capable of performing virtually all the calculations that can be undertaken by these other packages, although some functions are operated in a rather different manner. I shall therefore concentrate on the differences rather than the similarities.

Firstly, Inter-Sheet has an introductory menu of a type that will be familiar to users of Wordwise. This allows the standard loading, saving and printing operations to be carried out from the screen menu, and also permits default options to be set for the screen display. A nice feature is that the user is warned when attempting to load a new sheet from disc, if another sheet 1is already in memory, and also when attempting to save a file with the same name as one already on disc. This alone may sell the product to those prone to forget such details!

The function keys are used as in ViewSheet to edit and format cell contents, to set the re-calculation mode, and to insert and delete rows and columns. However, just one function is allocated to each, allowing the user to program them, using Shift and Control, for his own requirements. In addition, one key is used to toggle the display between 40, 80 and 105 character modes, if available free memory permits.

Yes, 105 characters can be displayed across the screen, using a specially defined character set in mode 0. The legibility of this depends on the quality of your monitor. I found it just readable on a standard quality Microvitec, and quite readable on all monochrome monitors. The 105 character display is of great value as it means that a 12 month budget complete with row labels and an annual total can be viewed on a single screen. The disadvantage is that such a display uses a great deal of memory, although this can be overcome by using a B-Plus or a screen memory expansion board.

All the usual commands are available, implemented in a form similar to Ultracalc (i.e. / followed by a single letter), giving an effect that can be applied to a single cell, a row, a column or the whole sheet. At each stage, user-friendly prompts are issued to guide the inexperienced user easily through the process. At first sight, the replication command (/COPY) seems inadequate as it allows only relative replication. Admittedly this is the most commonly needed method, but absolute replication can be obtained by using the BOX command in a formula to preserve absolute co-ordinates. However, I soon got used to this way of doing things and have now come to prefer it. A full range of functions, such as SUM, AVERAGE, MAX and MIN are available together with all the Basic maths functions. In addition, conditional (IF) statements and look-up tables are provided.

The program is limited to row by row calculation, and can be put into manual re-calculation mode to save time whilst entering formulae on a large sheet (up to 255 rows and 64 columns is possible - although not both in 32K). Labels have to be entered preceded by quotation marks, and they can be centred as well as left and right justified. Column widths can be set individually and cells can be formatted in a choice of three ways including a fixed number of decimal places. It is also possible to protect any part of the sheet against accidental alteration. Negative numbers can be indicated by either a minus sign or brackets, and the /PRINT command allows control codes and text to be sent directly to a printer prior to printing all or part of a sheet.

An ingenious feature is the /HOLD command which permits any row or column to be held at a fixed position on the screen whilst the remainder of the sheet is scrolled. Thus, for example, top and left-hand side headings can be fixed permanently; further, row and column totals can be fixed at the right-hand side and bottom of the screen if required, leaving a central window through which the whole sheet can be viewed and changed. This allows the effects of changes to be seen instantly. Although this feature is not quite as versatile as the Viewsheet windows, it is much easier and quicker to use and more than adequate for most purposes.

Although I began using Inter-Sheet with the feeling that it was inferior to the other spreadsheet programs, it quickly won me over in use. The features of Inter-Sheet, Viewsheet and Ultracalc all differ to a certain extent, and there is no overall best buy. It depends on what you need.

Viewsheet has sophisticated screen and print windows, but requires all columns to be set to the same width; Ultracalc works with the second processor but it is slow and not well-protected against errors; Inter-Sheet has the 105 character screen and is very user-friendly. It also appears able to deal with a larger spreadsheet than either of its competitors and re-calculates more quickly. For the new user, I think Inter-Sheet is the easiest system to begin with except for the fact that it is uncharacteristically let down by its manuals. The Introductory manual is very uneven and fails to get to grips with explaining why you might want to be using a spreadsheet, and how to make it do what you require. The Reference manual is adequate, but aimed at the competent user. A useful prompt card is provided. With this one reservation, I am happy to recommend Inter-Sheet as a competent spreadsheet package.

However, I have not yet mentioned the major novel feature of Inter-Sheet which is that it is part of Computer Concepts' ROM-LINK system. The sheet program itself occupies one 16K ROM whereas the second ROM holds the ROM-LINK commands. These permit several (up to 16) sheets to be held in memory simultaneously in different segments of memory. Not only that, but information can be easily exchanged from one sheet to another, allowing the results of one set of calculations to be incorporated as data in another sheet, or even from one package to another. Other ROM-LINK packages allow sheets generated by Inter-Sheet to be incorporated in documents, to be printed as graphs or charts, or to be fed into a database. This all happens directly in memory without first spooling the results to disc to be loaded again into another package. At present only Inter-chart (the graph and chart drawing package is available to fulfil this potential.

Inter-chart provides a means of generating graphs and charts from data. It can operate in a stand-alone fashion, obtaining its data by keyboard entry or from an ASCII file, or it can import data from a spreadsheet held concurrently in memory. Thus data held in Inter-Sheet can be displayed as a graph by instructing Inter-chart to access the relevant row or column. If the data consists of a set of labels (e.g. headings such as months of the year) and a set of numbers, it may be displayed in any of three formats (line graph, bar chart or pie chart). The type of chart can be quickly changed, as can the display mode (modes 0, 1, 2, 4 and 5 being possible) .

Computer Concepts' usual form of menu allows the graph to be displayed and edited, and also permits the colours for each section of the chart to be selected from those available in a given mode. Further, a variety of hatched patterns can be obtained, although a considerable amount of experimenting is necessary to obtain the best results. Up to 16 different graphs can be held in one set of charts, and up to 16 sets of charts and sheets can be held simultaneously.

Further, line graphs and bar charts can be overlaid on one another (see screen 1), and headings and legends added, permitting a variety of presentations to be constructed. Unfortunately the display in some modes (particularly modes 2 and 5) cuts off some text at the edges. Perhaps the most generally useful display mode is mode 1 which allows four colours with 40 column text; for printout mode 0 gives the best detail. Both modes 0 and 1 use 20k of memory, limiting other data storage. The editing features are impressive.

Scales are initially adjusted automatically to fit the incoming data, but can then be adjusted manually, with logarithmic scales being available if required. Data points can optionally be marked with a cross or joined by a line. Labels can be displayed or omitted, and a single data point can be highlighted. Finally, when the screen display is satisfactory, a single press of a function key dumps the screen to your printer (Epson-compatible only). This is a fixed size (approx. 6" x 8"), although instructions are given for using other screen dump systems, such as Printmaster or Dumpmaster, which allow the size to be selected.

One odd feature is that data that consists of pairs of numbers (as when drawing an X-Y graph) must reside in adjacent columns of the spreadsheet. This is a pity as most spreadsheet models naturally keep such data in rows. Also, although headings are easy to add, they can be quite difficult to edit or remove.

Overall, ROM-LINK appears to be an excellent system, which works well in so far as I could test it. I was able to keep several different sheets in memory and to transfer information between them and the graphics package without problem. However, as even a small sheet takes up a fair deal of memory (e.g. a 15 column by 27 row budget took up 16% of the available mode 7 memory and 42% of the mode 3 memory), and as word processors are equally memory hungry, I am not convinced of the practical usefulness of this system on an unexpanded 32K Beeb. Once graphs or charts are constructed, memory requirements escalate rapidly. The ROM-LINK system provides a strong motivation for up-grading to a B-Plus or fitting a screen memory board.

The two packages reviewed here are quality products well up to the standards we have come to expect of Computer Concepts. Inter-Sheet is easy to use and difficult to make disastrous mistakes with, although it is a pity that the introductory manual lets it down. Inter-Chart is a valuable addition and, when the promised ROM-LINK word processor and database arrive, they will all form an impressive system. Inter-Sheet and Inter-Chart are of a similar standard to software that is sold for 16-bit machines at considerably higher prices and, within the constraints of the BBC's limited memory, enables highly professional work to be carried out.