- on Fun and Games
- Published in issue 9/1981 on page 22
TV games extended
9-22 â€” elektor september 1981 TV games extended The extended version This extension to the TV games com- puter was designed, quite literally, in._ response to repeated requests from readers who wanted more "elbow room". The best way to illustrate the new fea- tures is by means of a memory map as shown in figure 1. In the basic version, the monitor occupied the first 2K of memory and this was followed by 2K of RAM (1 3/4 R for the user). The address range from 1000 was virtually unused - it only contained a few input/output lines and the PVI. Now, a further 3K RAM is added, from 1000 to 1BFF, and two programmable Sound Gener- ators (PSGs) are located at addresses 1D00 to 1D 1F . The area from 1800 on gets rather confused, owing in part to a minor error in the original monitor ROM. The Read Cassette address is located at 19BF, instead of 1DBF where it belongs. Since the addresses in this range were not fully decoded, this made no differences at the time. Now, it complicates matter...