I’ve had several SYM-1s in my collection for a few years but never really did anything with them. One did not work when I got it so about a year ago I spent time to remove all the memory jumpers; lots of traces were cut around the memory map jumpers. Over the last week I got things re-configured and now it runs BASIC in an 8K ROM quite nicely. The Synertek documentation about configuring jumpers had some errors in it, but a look at the schematic made it easy to figure out.
Every now and then a SYM-1 owner asks if my KIM boards work on a SYM, and I can now verify that the memory boards certainly do. There is no need for the I/O board as the SYM already has both 20ma and RS-232 drivers. The memory board plugs into the E connector and works great except that the KIM and SYM memory maps are slightly different so there is a minor problem. On the KIM, everything is on 8K boundaries; the on-board RAM, ROM and I/O fit exactly in the first 8K. My board is selectable on 8K boundaries such as 2000, 4000, etc. The SYM has unmapped memory starting at 1000 so my board can’t fill in there, nor any other of the 4K areas. So, while it works, it’s not ideal. I think my next project will be a RAM board tailored for the SYM (hint).
One of my other projects has been getting a good source code port of the FOCAL-65 3D interpreter. Right now I can build and run it, but there are a lot of unknowns about some areas of the disassembly that don’t seem to be used anywhere and might be position dependent. While fun, this project might be moved to a background task.