CoCo Editor

on expr go sub

The underlying code for my coco editor is done. The last piece was on expr go sub label list. It gave me fits. I kept dumping the stack and making on 2 go sub label list the same as on 1 go sub label which is handled by the basic rom. The trick was the top two words on the stack. I figured they were just there for the error control. Well, they are. The on 1 go to label and on 1 go sub label both had the same two words on the top of the stack. When I put them on the top of the stack for on expr go to label list and on expr go sub label list, my problems went away. I put an on expr go to label list into my sample program and it worked just fine. A word about my sample program. I call it EARL. Easy Assembler Robot Language. That just happens to be my name. Back when the coco 2 was great stuff and programs were saved on cassette tapes a professor out in California wrote a program he called KARL. He showed how one could add two distances to each other. He offered to send a copy of his whole program to anyone who showed how to multiply two distances together before the next issue of Rainbow magazine, bigger than Life or Look, devoted to the coco, came out. I caught fire. I wrote my first Earl program and developed my multiply program. I typed it up and sent it in. On of his students typed it into a coco. He made a couple of typos and it didn’t work. I fired off a letter explaining how I had written my Earl program to develop my multiply routine. I put them on a cassette tape and sent it in. The tape had a bad spot on it and it wouldn’t load. He replied to me that he didn’t believe anyone could develop the programs that fast. I should have copied it onto a new tape and sent it in. I kept trying to make it better. I wanted to make it print itself out onto a printer. I never got it good enough. It’s always festered in my mind. I’ve developed my coco editor similar to the program I had back then. Then I had only single letter labels, opcodes, and addresses. Now I have two letter labels and addresses. That way I don’t need line numbers. In my last attempt I had labels and variables with all their characters significant. But I didn’t have on expr go to and go sub label list. Now I’m going to put them together and have the whole enchilada.

By earlcasper

Retired US Postal Clerk. BS at University of Washington. Studied computers at Arizona State University. Lives in Kansas City KS.

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