80-Bus News

Conclusion

This system has been in use for several months now, and I must say that I am very pleased with it. I use my Nascom a damn sight more often than I did when I was relying on audio cassettes. I now use my Nascom for actual serious work (i.e. with huge ZEAP/​NASPEN, etc. files)… when was the last time you dumped several 28K files to (audio) tape in an evening, eh?? And how often does it refuse to verify, meaning you have to do the whole thing again? With the HS1N, no such problems occur, as verification is automatic (as I’ve mentioned). If a block fails to verify (which usually means you are using uncertified tapes) it will try again… in the meantime you can go away & make a cuppa or whatever. Above all, this system is so fast compared with the old CUTS system that you will soon wonder how you ever managed without it!

The few points I criticised don’t detract from the system’s usefulness & versatility, they just make the system look a trifle untidy. They really need attention though, for a more ‘professional’ finish… an ‘issue 2’ release, perhaps? I could make a long list of extra commands it would be ‘nice’ to have, in addition to the ones I have already added, e.g. Loading a named file, Append ZEAP/​NASPEN/​BASIC file, auto-relocation of ZBAP file when loading (useful if you need to relocate the ZHAP buffer)… but then TOS wouldn’t occupy 2K (it would be more like 4K). There is no reason why the intrepid user shouldn’t add his own commands, if he/she wishes…

Since I bought the system from Microspares in Edinburgh it has achieved ‘Nascom Approved’ status, so perhaps some of the points I have mentioned have received attention. I should also think that the HS1N will now be available through your friendly local Nascom dealer.

One final thought…​this article was prepared using NASPEN. The file will take about 30 seconds to save & verify. The Editor likes NASPEN (CUTS) tapes [Ed. – or disks!]. It will probably take about half an hour to dump it & verify it. Now where did I put that old cassette recorder…

Recently (much to the disgust of my Bank Manager) I have purchased a disk system, the Gemini G809/G815 running with Polydos, which is an excellent product and I have been able to interface all my existing software so that the I/O can be either Disk or Tape.

However, one of the problems that I had was producing backup copies, and after having one disaster (entirely my own fault) doing a backup with a single disk system, I decided to write a Tape Backup Utility. This utility reads in all the files on the disk and writes them to tape, some common files can be omitted by placing the file names in a list. The user only has to load the disk, set the tape on to record and run the program, then the Backup is taken automaticaly. The files are written onto tape in a similar way to the Generate command. To recover the files you simply set the tape unit to play, and each file is read into memory. Stop the tape after the file required has been read and then use the Polydos ‘SAVE’ command to restore the data. All files are located at £1000 upwards (and must be less than £B000 long), each file is identified and the load and execute addresses are displayed. All files are copied including ones that have been ‘Deleted’. I have enclosed two listings the first a full Assembly listing and the second a dump using a slightly modified version of the DUMP utility published in vol 1 issue 2 (The addresses on the left hand side are the RAM addresses ), the program loads and executes at £0C80. Using this program it is possible to backup a disk in a few minutes with the cassette running at 4800 Baud, depending on how full the disk is (I run my cassette at 6000 baud without any trouble).