TRS-80 Model 6000
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| Exploded view of the major assemblies, from Tandy's 1985 service manual | |
| Specifications | |
|---|---|
| Manufacturer | Tandy Corporation |
| Type | Multi-user business computer |
| Released | 1985 |
| CPU | Motorola MC68000 (8 MHz) and Zilog Z80A (4 MHz) |
| Memory | 512 KB for the 68000, expandable to 1 MB; 64 KB for the Z80A, expandable to 128 KB |
| Storage | 6000: two Tandon 8-inch Thinline floppy drives; 6000 HD: one floppy drive and a 15 MB Tandon TM503 hard disk |
| Display | Built-in green monochrome monitor |
| Sound | — |
| OS / Firmware | Xenix; TRSDOS |
| Predecessor | TRS-80 Model 16B |
| Model no. | 26-6021, 26-6022 |
The Tandy 6000 is the last of Tandy's business computers descended from the TRS-80 Model II. A Motorola 68000 runs Xenix and user programs, and a Z80A I/O processor, software compatible with the Model II, handles the disks, ports, keyboard and screen.[1][2] It replaced the TRS-80 Model 16B in 1985 and was sold under the Tandy name alone, without the Radio Shack and TRS-80 badges of the earlier models.[3]
History
[edit | edit source]The TRS-80 Model 16 of 1982 became the Model 16B with 256 KB in July 1983, and the Tandy 6000 followed in 1985 with an internal hard disk option, ARCNET support and an 8 MHz 68000. Tandy sold an upgrade from the Model 16 to the 6000. For the line, it offered external hard disks of 8.4, 15, 35 and 70 MB and up to six extra RS-232 ports for multi-user terminals.[3] The 6000 came with Xenix and TRSDOS, though few owners ran TRSDOS or CP/M, and the machine cannot boot from its hard disk. In 1987 Tandy announced that the 6000 hardware would not be developed further, and by 1988 Radio Shack was selling 386 PC compatibles for professional users and had retired the Model II family.[3]
Hardware
[edit | edit source]The 6000 is built as a display console, with the screen, drives and electronics in one case, and a separate keyboard on a coiled cable. The electronics module in the base carries the I/O processor board and the power supply, with a seven-slot mother board standing in the middle of the I/O processor board for the 68000 CPU, memory, video and option boards.[1][4]
| Assembly | Tandy part no. | Main parts and functions |
|---|---|---|
| Mother board | 8897701 | Seven card slots, J1 to J7 counted from the bottom, and extra filtering of the supply input |
| MC68000 CPU board | 8898855 | MC68000 (8 MHz part) and AM9519A interrupt controller; clocks derived from a 48 MHz crystal; eight levels of vectored interrupt, four levels of bus arbitration, up to 7 MB addressable |
| Memory board | 8898854 | 512 KB with optional byte parity; can be mapped on any 256 KB boundary; 1 MB supported by the software |
| I/O processor board | 8898423 | Z80A at 4 MHz with DMA, CTC, SIO (two RS-232 ports) and PIO (parallel printer port); floppy disk controller; 64 KB of RAM, expandable to 128 KB; 2 KB boot ROM |
| Video/keyboard interface | 8898022 | MC6845 CRT controller and the serial keyboard interface |
| Power supply | 8790047 | Astec AA11082, 140 W switching supply |
| Sound board | 8898429 | Key-click tone; mounted in the base at the left front |
| Keyboard | 8790522 | 82-key low-profile capacitive keyboard with eight function keys, scanned by an 8021 microcontroller |
| Hard disk controller (6000 HD) | 8898798 | WD1010 controller for one internal and one external 5.25-inch drive |
| Video monitor | 8790614 | TCE monitor board; the manual says monitors came from several makers |
Sources: service manual sections 1, 2, 7 and 8 and the parts lists.[1][5]
The I/O processor board is described as functionally equivalent to, and software compatible with, the Model II.[2] The service manual's own troubleshooting of the CPU and memory boards starts by running the Model II diagnostics, as the Model 16 manual does.[6]
Drives
[edit | edit source]- The standard 6000 has two Tandon Thinline floppy drives; the manual's appendix covers the TM848-1E and TM848-2E, 8-inch, 48 tracks per inch drives. The optional disk bay expansion unit takes one or two more drives, holding 500 KB per single-sided or 1 MB per double-sided double-density diskette.[1][7]
- The 6000 HD replaces the second floppy drive with a 15 MB Tandon TM503: three 5.25-inch platters, six heads and 306 cylinders. The drive has its own 38 W switching supply, model AA 11330, which also runs a 12 V fan under the drive tower.[8]
- The hard disk controller uses the Z80 interrupt daisy chain, so it must sit in the bottom card slot, or the one above it when an ARCNET board is fitted.[8]
Two internal layouts
[edit | edit source]The manual has separate cable diagrams for "Version 1" and "Version 2" machines. A 6000 whose fan sits in a metal housing on the back of the access panel is to be taken apart using the Model 16B service manual; other units follow the 6000 manual's own procedure.[9]
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Console (W x H x D) | 21.0 x 13.5 x 20.5 in (53.3 x 34.3 x 52.1 cm); 49.9 lb (22.5 kg) |
| Keyboard (W x H x D) | 18.0 x 2.5 x 7.5 in (45.7 x 6.4 x 19.1 cm); 3.3 lb (1.49 kg) |
| Mains | 95-135 V AC (US) or 190-270 V AC (Europe), 47-63 Hz; 1.5 A typical, 2.0 A maximum |
| Operating temperature | 55-85 °F (12-30 °C) |
| Serial ports | Two RS-232C on DB-25 connectors; channel A asynchronous or synchronous, channel B asynchronous |
| Printer port | Parallel, 34-pin connector; 8 bits out, 4 bits in |
| Expansion | Four free slots for hard disk interface, graphics, ARCNET and multi-terminal boards |
Source: [1]
Software
[edit | edit source]Xenix and TRSDOS were supplied with the machine.[3] The boot ROM reads track 0 of the floppy and looks for the strings "BOOT" and "DIAG"; a disk without them gives "BOOT ERROR RS", meaning not a Radio Shack diskette. TRSDOS 4.0 and later need an extra 16 KB above the first 64 KB, taken from Z80 memory or the 68000's memory, which the boot diagnostics do not test. If it is missing or faulty, loading stops with "LOADING" on the screen and no error message.[6]
Known faults
[edit | edit source]- No fault reports specific to the 6000 were found. The trs-80.com repair notes, which cover the whole range, warn that the bleeder resistor in the CRT anode cap can fail open and leave the tube charged; the writer's own Model 16 had this fault.[10]
- The service manual's boot error codes and board charts are listed in the TRS-80 Model 6000 Troubleshooting Guide.
Documentation
[edit | edit source]- Tandy 6000 Service Manual: disassembly, adjustments, troubleshooting, theory, schematics and parts lists for every board, with appendices for the monitor and the Tandon drives
- Radio Shack TRS-80 Model II Technical Reference Manual: referred to by the 6000 manual for Model II diagnostic failures
Related pages
[edit | edit source]- TRS-80 Model 6000 General Maintenance
- TRS-80 Model 6000 Troubleshooting Guide
- TRS-80 Model 6000 Capacitor Replacement Guide
- TRS-80 Model II
- TRS-80 Model 12
- TRS-80 Model 16
- TRS-80 Model 16B
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 Tandy Computer Products, Service Manual, Tandy 6000/6000-HD, catalogue numbers 26-6021/2, 1985, hosted as File:Tandy 6000 Service Manual (26-6021, 26-6022, 1985).pdf. Section 1, "Introduction", pp. 1-5, and Section 2, "Technical Specifications", pp. 7-8.
- ↑ 2.0 2.1 Service Manual, Tandy 6000/6000-HD (1985), Section 7.4, "Main Logic Board", p. 121.
- ↑ 3.0 3.1 3.2 3.3 "TRS-80 Model II", Wikipedia (retrieved 2026-10-21). Section "Model 16B and Tandy 6000".
- ↑ Service Manual, Tandy 6000/6000-HD (1985), Section 7.1, "Mother Board", p. 55, and parts list p. 59.
- ↑ Service Manual, Tandy 6000/6000-HD (1985), Section 7, "Theory of Operation": 7.2 CPU board (clock logic; parts list pp. 93-95), 7.4 main logic board, 7.5 video/keyboard, 7.6 power supply (p. 193), 7.7 sound board, 7.8 CRT assembly, 7.9 keyboard, 7.10 hard disk controller.
- ↑ 6.0 6.1 Service Manual, Tandy 6000/6000-HD (1985), Section 6, "Troubleshooting Procedures", pp. 47-54.
- ↑ Service Manual, Tandy 6000/6000-HD (1985), Appendix B, Tandon TM848-1E and TM848-2E Thinline Flexible Disk Drives OEM Operating and Service Manual (1983), section 1.
- ↑ 8.0 8.1 Service Manual, Tandy 6000/6000-HD (1985), Section 7.10, "Hard Disk Controller", pp. 219-228.
- ↑ Service Manual, Tandy 6000/6000-HD (1985), Section 3, "Disassembly/Assembly Procedures", pp. 9-18, and Section 5, figures 5-2 to 5-5.
- ↑ Ira Goldklang, "TRS-80 Troubleshooting Guide and Repair Q&A", Ira Goldklang's TRS-80 Revived Site (retrieved 2026-10-21). "All Models" section, "CRTs".