Sharp PC-1211/TRS-80 PC-1 program tapes from Radio Shack

[Dave Britten]

My pleasure! I enjoy archiving old software to keep it from being lost to time. There's plenty of effort being done to preserve games and major non-game releases, but less for for obscure stuff like this.

I loaded the stocks program into my PC-1211 to check your math. The MEM command reports "362STEPS" free with the program loaded, meaning it does in fact occupy 1062 bytes (1424-362), matching the size of the .bin file.

On this model, however, variables occupy 8 bytes each, not 7. The MEM command reports "45MEMORIES" available after the program is loaded. Each stock occupies three variables, meaning 57 variables are needed to hold 19 stocks. With the program storing the stocks in fixed memories O-Z, and then the flexible memories at A(27) and beyond, this gives 12 + 45 available memories, or 57 total. So just enough room for 19 stocks. If you try to add another stock when N>18 (i.e. N=19), you get the "TOO MANY STOCKS!" error, since memory is already full. A nice example of using every last byte of memory.