TRS-80 Model II

2021-10-03 (updated 2 days and 8 hours ago)

Quick refresh, the TRS-80 Model II is not compatible with the Model I, Model III, Model 4 or variants
The TRS-80 Model II had several successors in the line:
TRS-80 Model 12
TRS-80 Model 16
TRS-80 Model 16B (68000 built-in)
Tandy 6000 (68000 built-in).
Tandy 6000 HD (68000 built-in).

Had a z80 CPU with a 68000 CPU add-on option (later models included the 68K)
Used 8" floppy disks or an ultra rare and expensive (even when it was new) hard drive.
Built-in monitor and disk drive
Marketed exclusively to businesses.
Available OSes include TRS-DOS, Xenix, CP/M, LDOS
Available languages include BASIC-80, TRS-80 Level II BASIC, COBOL, FORTRAN, C, PASCAL. Only BASIC-80 was available as interpreted, the other were for compiling. The TRS-80 Level II BASIC for the Model II lacked cassette, graphics, peek and poke commands and system commands could not be executed from BASIC (basically, it couldn't run _any_ Model I/III/4 games). However, the BASIC-80 was very advanced having 11 graphics commands including "bit patterns" (software sprites or pattern fills), and ways to do collision detection and windowing. It was actually easier to run Model I/III/4 BASIC games by translating them to BASIC-80 code rather than TRS-80 Level II BASIC for the Model II. Using the 68000 CPU basically made it a different computer that only Model II specific 68K operating systems and software would run on. It actually had an advantage over other 68K computers at the time since the z80 and it's memory handled the hardware end of the system (I/O, network, keyboard, disk access) and left the 68K with it's own memory to run unhindered. There was a shared memory area and it was possible to put the z80 to general uses at the same time as the 68k but no software was ever designed to use this feature.

With a 68k, the computer could be put to good use as a multiuser system and in fact the last two models were advertised as such. While most multiuser systems limited the users' choices to one operating system (usually provided by the manufacture), the Model II series supported multiuser capability with LDOS, CP/M, and Xenix. Out-of-the-box, two terminals could be attached for three simultaneous users. Add-on cards with 3, 6, or 9 ports allowed additional terminals. 3rd parties made cards supporting more than 9 ports. While this could allow more total users, it was probably more useful as a way to free up expansion slots for other cards.

Well, there's apparently games for it.
SeaWolf. A scrolling shooter, of all things. Pilot a submarine in underwater caverns.
Scott Adams Adventures
Infocom Adventures