Open Access Users Group October 1995 Meeting Blunder with last newsletter Our apologies for the mix up with the last newsletter, which was supposed to cover the September meeting. There was a mix up (by Michael Paine) with the word processor file and the notes about the May meeting were used instead. How many of you noticed? The September notes are included with this newsletter. Q & A Conversion of database time fields to dBase3 format. The OA File Converter includes provision to convert an OA database to dBase format, which can then be used by most of the new "Windows" database packages. Michael Paine has written an OA application for data entry on "old" PCs (e.g 286s - the speed is fine if you are happy to use a DOS screen). Summary information is then generated and converted to dBase format for use on the organisation's networked PCs which use MS Access. Michael has found an error in the conversion routine for time fields. The OA4 Utilities manual mentions that, because dBase3 does not have time fields the OA File Converter converts OA time fields to 'seconds since midnight'. During tests Michael found that the algorithm adds one minute for every hour . For example 1:30AM is converted to 5460 seconds instead of 5400 seconds. The algorithm is built into OA3/4 and cannot be changed therefore the output needs to be manually corrected - the formula is: S = A - 60*INT(A/3660) where A is the value derived by the OA File Converter Therefore if A=5460 then S=5400. Memory problems with Programmer/Compiler ( IF EXTRACT(s1,1,4)='A') Michael Paine has noticed that a program which works perfectly well with a small number of test records ran out of memory ("not enough memory") when he used the full data with many thousands of records. He checked for "implicitly declared variables" (see Programmer manual) but could not find any source of the problem. Then he tried replacing functions within IF statements with variables and the problem was fixed. It seems that the use of some functions within if statements can use up memory each time around a loop. s1='test string' IF EXTRACT(s1,1,1)='t' ! do something END IF should be replaced by s1='test string' s2= EXTRACT(s1,1,1) IF s3 = 't' ! do something END IF Spreadsheet Recalculation During experiments with the time conversion problem Terry pointed out that the OA Spreadsheets display the letter "R" in the bottom left had corner if recalculation is required. This assumes that auto-recalc is "off" ( Set-up Auto-calc). Hiding spreadsheet columns First question is why would you want to hide a spreadsheet column! In fact there are occasions when you need to make interim calculations but you don't want to display the results. There are two ways to hide a column. 1. set the width to zero (Format Width 0 ) or 2. change the cell attributes to Invisible (Format Attributes [column letter]). Printing selected areas of a spreadsheet Terry also demonstrated a neat way to print selected areas of a spreadsheet. First Name the areas you wish to include in a printout (Name [cell range]). Then include the following type of expression in vertical range of cells: ^area('data). For example A 1 ^area('input) 2 ^area('output) To obtain a printout of the two named areas just print the cells a1:a2. Barcode printing Lindy Kidman sought advice about the control codes for printing barcodes on a Fujitsu printer. After looking at the printer manual Terry suggested some control codes to use in the 64 impossible questions of the OA Printer Configuration (has it worked?). Lindy pointed out that her "vintage" printer had built-in capability to print barcodes but that most modern printers do not have such capability. Technology Update System Manager Version 6 Datapac have announced the release of version 6 of their Unix-like multi-user DOS "System Manager". Amongst the enhancements is the ability to run Windows from any VGA "terminal" on the system. For example you could set up a System Manager "network" comprising a 486/Pentium host PC and, say, 10 "terminals" of those old 286/386 PCs around the office (or at home via modem) and run Windows software on the old PCs. In fact the software runs on the host PCs - only graphics, keystrokes and mouse actions are transferred between the host and terminal - not megabytes of data and software. This enhancement was made possible by some clever techniques to manage screen refreshes on the terminals. Remember that your host PC can, in turn, be part of a Novell network and so all of the System Manager users can be linked to the network. Don't expect graphics intensive applications (eg CAD) to perform as well as a standalone system but disk intensive applications such as databases should fly because data and processing are on the one PC - the host! Version 6 also allows Windows 3.1 to run in enhanced mode. It will not run Windows 95 but why would you if you are intending to run a multi-user environment - apparently Microsoft advises against using Windows 95 with more than 3 users. British Telecom recently installed a large System Manager system to automatically poll hundreds of thousands of pay phone throughout Britain to check for breakdowns. The results are logged into a VAX computer which is used to organise repairs. Windows 95 Talking about Windows 95 - have any users installed it? Does OA run okay? Apparently Apple Computer company said "the world has just been subjected to the largest hype campaign in the history of personal computing. Most of the new features of Windows 95 have been available on the Macintosh for so long that Mac users take them for granted". Interactive Video After the break the group was treated to a presentation by Brian Faull and Marie Anderson. The Interactive Video Company produces interactive videos for education, marketing and entertainment. If you have used CD-ROM software such as "A Brief History of Time" or "Encarta" on a PC then you know about interactive video. What Brian demonstrated was a machine which plugs directly into your TV. The special remote control becomes the "mouse" control. The latest generation of video CDs will allow at least two hours of video with full stereo sound so you will soon be able to hire/buy your favourite movies on CD rather than video tape. The quality is excellent, with none of the jerky motion evident on most PCs. The major advance, however, is the ability to make the show interactive. Because the machine can jump to any spot on the CD the show can be programmed to change according to user input via the "mouse" (actually a cursor on the TV screen controlled via the remote control unit). Brian demonstrated the interactive movie "Crocodile Island" which his company has produced. The video CD player will probably sell for around $500 in Australia. Apparently TVs with built-in CD players are already on the market in the USA. The interactive technology will also apply to some pay TV services. There is potential for huge amounts of information to be accessible via a TV, control unit and pay-TV cable. When you think about, the typical multi-media PC is a rather poor method of managing large amounts of video/audio information. All the data stored on the CD ROM must be channelled through the data circuits and CPU of the PC before it is finally converted to video output. If you do not need a keyboard (for fast typing) then you may as well linked the CD drive directly to a monitor (the TV). The savings in cost and complexity could be substantial. For example schools could purchase four or five self-contained Video-CD TVs for the price of one multi-media PC and there would be no hard-disks to crash and no keyboards to pour paint over! Our advice is wait a few months. Don't buy a new PC just for multi-media or internet access - they may be redundant technologies in a year or two. Don't buy a new video tape recorder or even a new TV. Don't even buy a new audio CD player because the video CD player will play audio CDs. Oh dear - what will the electrical retailers think of this advice just before Christmas? NEXT MEETING We hope that John Wheeler will be able to give us a presentation on Borland's Delphi application development software for Windows.