INMC 80 News

One of the projects I have in hand is an audio to video display system. By this I mean a type of programmable sound-to-light consisting of several audio filters each controlling one bit of a port. The port is read and used as the basis for a display on the monitor. The filters are proving the main difficulty and the idea is still on paper only. Has anyone else tried anything similar?

You may have read the article on “Adventure” in the August edition of Practical Computing and mentioned by Dr. Dark in the last newsletter. One of the great features of this program is its portability of databases. While it is easy enough for anyone to implement the program in machine code, unless certain standards are conformed to, the whole object of the program is defeated. I have been trying to define these standards with Chris Southern (he wrote a letter to PC about the program) but I realise others must be brought in to contribute to this process otherwise our efforts are largely wasted. I invite everyone who is even vaguely interested to write to me so that a proper “net” can be established.

Lastly, a modification to the tape interface which lets you play music on the cassette without writing rubbish on the screen. A relay controlled by TP10 is one way of tackling this, another is to connect pin 10 of IC30b (ENABLE) to the bit controlling TP10 and the LED. IC30 must be removed and pin 10 bent out. One end of a short piece of insulated wire (approx. 1.5″) should be soldered very carefully to pin 10. The other end of the wire should be inserted into pin 12 of the IC socket of IC24 (Q4). The operation is very simple. When Q4 of IC24 goes high it turns on the LED but now it also enables IC30b activating the receive data clock for the UART. When low, IC30b is disabled, the UART does not get the “receive clock”, and anything on RDATA is ignored.

Luan Thompson, OXFORD

Remarkable Graphics

In issue 7 of INMC News you gave the Nascom Graphics characters. In all of these characters the bottom two lines of the 8 x 16 cell are blank! However, the characters still run into each other (apparently) from one cell to another. This is remarkable!

D. Smith, Stockton-on-Tees

Ed. – Not all that remarkable: Nascom 1 has 16 TV lines per character, Nascom 2 has only 14. The diagram was for Nascom 2.

Thanks

Thanks for everything you are doing. Don’t forget us Nascom 1 types will you?

R.C.Ridgwell, Gt. Torrington

Regular fixes

INMC80-2 arrived today, just in time to stop the withdrawal symptoms from driving me to the funny farm. Please keep the fixes coming (even put up the subs. if necessary). Thank you for your excellent work.

F.A,​Whitby, Nottingham

Ed – We do say that Nascoms are addictive, but this is ridiculous.