ZX81 callsign database.

[HMV 1120]

The fruits of an evenings labour! I determined to put the 1k ZX81 to useful work rather than writing interesting monochrome 'screensavers'. As it currently lives alongside the ham radio gear it made sense to put it towards some ham application.
An hour later and I have instant access to a database of callsigns, names and locations, all taken from last years log book. Atlast! A useful program!


Well, sort of. The first version handled 20 callsigns and their details but could only display one search result at a time. Entering a second result required re-entering 'RUN'.

Version two continues to search and display listings until either 'EDIT' is entered (taking you back to the source code and allowing the database to edited) or the screen memory runs out. With 1K this occurs after four or five listings. The extra code introduced has cut the database capacity down to 14 entries. With a 16K rampack therefore, around 220 callsigns could be stored(!).

Photo's show the initial code, callsign entry and database listing (G2XV is the callsign of the Cambridge and District Amateur Radio Club and is widely published on the web).
Copies of the full code via e-mail or floppy disk to anyone interested.

The final photo is the ZX Spectrum I had donated today, it needs new keyboard 'leads' before it will do anything useful though.

Regards,
Robert B.