In the April 1983 issue of QZX, Larry Willson presented his RTTY program, If you were like me, the prospect of rtty made normal life impossible. That version of rtty was admittedly primitive; after a full screen on either transmit or гесеіvе, the program stopped. Never the less, it did work.
When his “more sophisticated” RTTY program arrived, I immediately tried it. Even though the interface for the first was different than that for the new version, the “more sophisticated” program ran without problem.
With the cassette came a single sheet of explanation and another with the new interface schematic. The new interface is a simplified version of its predecessor, containing only 4 I.C.s and a very few other components, all of which are available from Radio Shack.
The explanation sheet was short but sufficiant. It did contain the statement that the program would run in two k of ram, no more or less and the fact of the matter is that the 2. program will run with the 16k version as well by setting ramtop to 18432 after it is running. The display file characteristics change below. 3.3K of ram and I think that the AF8J RTTY program takes advantage of these differences.