TRS-80 Model 4
| Manufacturer | Tandy Corporation | 
|---|---|
| Type | Home and small business computer | 
| Release date | April 26, 1983 | 
| Introductory price | $1999 (64K, 2 floppy drives, RS-232C), $1699 (64K, 1 floppy drive, no RS-232C) | 
| Discontinued | Late 1991 | 
| Operating system | TRSDOS 6.2, LS-DOS 6.3, TRSDOS 1.3, LDOS 5.3, CP/M 2.2 or 3.0 | 
| CPU | Zilog Z80A @ 4 MHz, 6+ MHz with Z80B / Z80H, or HD64180 / Z180 | 
| Memory | 64 KB or 128 KB, 1 MB plus with third-party upgrades | 
| Display | Model 4 mode: 24 rows, 80 or 40 columns, Model III mode: 16 rows, 64 or 32 columns, block graphics | 
| Graphics | optional 640 by 240 pixels for $249 extra | 
| Sound | beeper | 
| Backward compatibility | TRS-80 Model III | 
| Predecessor | TRS-80 Model III | 
| Successor | none | 
The TRS-80 Model 4 is the last Z80-based home computer family by Radio Shack, sold from April 1983 through late 1991.