>>> you often knocked loose the cable connecting it to the expansion interface.
>
>Ah yes, I had the mighty expansion interface that increased RAM to 48K. The other 16K was for the OS and Basic language. Amazing to think that these days a "Hello world" app might require more resources than the whole Trash-80 OS.

If I remember correctly, the expansion interface was required for the Model I for adding past 16K that the main unit (basically keyboard where the CPU was located) could hold, and was also required if you wanted to hook up peripherals (e.g. diskette drive, printer, modem, etc.). Also since the hardware didn't have provision for bankswitching, there wasn't a way to expand beyond 48K RAM (the first 16K was for ROM code and memory-mapped hardware).

One thing that I do remember is since the BASIC interpreter in the TRS-80 was a distant relative of the BASIC interpreter on the IBM-PC (both being authored by Microsoft), translating code from TRS-80 BASIC to IBM-PC BASIC wasn't too hard. It also happens to be that on a project involving porting TRS-80 code to the IBM-PC is where I'd encountered problem similar to the Y2K problem -- TRSDOS wouldn't handle take dates beyond 1984 (which was one of the big reasons why the move from TRS-80 to IBM-PC was done).

I do remember back when I got a PalmOS device for about $200 and realized that from computing ability and memory installed, it wasn't different from the 486-based PC that I bought back in 1991 for $2000. Looking at specs of the Apollo Guidance Computer, it's almost hard to believe (as seen from perspective of what you have with 21st century desktop computer) that it could've performed the tasks that it did.