Close

Running BASIC

A project log for Sol-20 Reproduction

I am making a full sized Sol-20 reproduction, the first fully assembled microcomputer with a built-in keyboard and television output.

michael-gardiMichael Gardi 02/20/2022 at 16:160 Comments

While I had tested my Sol-20 emulator on many programs (mostly games) I had not gotten around to running BASIC on the machine. Recently I found the MS_BASIC seemed to work fine, but the two Processor Technology offerings BASIC-5 and Extended BASIC had issues. With the help of some 8080 test programs I was able to track down a couple of 8080 instructions that I had not implemented quite right.  The changes were subtle but obviously significant. 

Once I had the BASIC interpreters running correctly I was keen to try out some of the many cool BASIC programs that can be found on Jim Battles great Sol-20 site. Most of these programs are quite long. Typing them in was not a viable option, so I added a new feature that allows you to "load" a text file as though it were being typed into the keyboard. 

Pressing ALT-L on a regular keyboard, or pressing the LOCAL key on Dave's SOL-20 keyboard will pop up a file finder dialog.  Once an appropriate text file is selected the characters in the file will be "typed" in via the keyboard interface. When the whole file has been entered manual control will be returned to the keyboard. 

The latest fixes and some BASIC programs to try out have been added to GitHub.

Discussions