Tandy 5000 MC
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| The Tandy 5000 MC with a VGM-300 monitor, from a Tandy advertisement of 1988 (public domain, via Wikimedia Commons) | |
| Specifications | |
|---|---|
| Manufacturer | Tandy Corporation, sold by Radio Shack |
| Type | Desktop personal computer with Micro Channel bus |
| Released | 1988 |
| Intro price | US$4,999 (2 MB, no hard disk) |
| CPU | Intel 80386, 20 MHz, on a plug-in CPU card |
| Memory | 2 MB of 100 ns SIMMs on a memory card; up to 16 MB on two memory cards; 32 KB cache |
| Storage | 1.44 MB 3.5-inch floppy drive; optional ST-506, ESDI or SCSI hard disk |
| Display | VGA on the main board |
| Sound | Speaker |
| ROM | 128 KB BIOS (Phoenix) |
| FPU / coprocessor | Optional 80387, 20 MHz |
| Ports / interface | Serial (DB-9), parallel (DB-25), VGA (DB-15), keyboard, mouse |
| Expansion | Five Micro Channel slots (two 32-bit, three 16-bit); two 32-bit memory slots; CPU card slot |
| Power | 192 W; 105-130 V AC, 60 Hz |
| Compatibility | IBM PS/2 Micro Channel |
| Dimensions | 6¼ x 15¹¹⁄₁₆ x 17 in |
| Weight | 28 lb |
| OS / Firmware | MS-DOS 3.3, MS OS/2 or SCO XENIX 386 (sold separately) |
| Model no. | 250-6000, 250-6001, 250-6002 |
The Tandy 5000 MC is a desktop computer built round a 20 MHz Intel 80386 and IBM's Micro Channel bus, made by Tandy Corporation and sold through Radio Shack. Tandy announced it on 21 April 1988 and shipped the first units in the last week of July 1988, making it the first Micro Channel computer on sale from a company other than IBM.[1][2] Like IBM's PS/2 machines it has VGA, the floppy controller and the serial, parallel, keyboard and mouse ports on the main board, and its Micro Channel cards are configured from a reference diskette, as on a PS/2.[2]
History
[edit | edit source]BYTE listed three packages in early 1989:[2]
| Package | Price |
|---|---|
| Basic system, 2 MB, 1.44 MB floppy drive | $4,999 |
| With 40 MB hard disk | $6,499 |
| With 80 MB hard disk | $6,999 |
Radio Shack's service documents give three catalogue numbers, 250-6000, 250-6001 (with a 40 MB hard disk) and 250-6002.[3][4] PC World found it faster than IBM's PS/2 Model 70-121 and cheaper for a comparable system, but noted an FCC Class A rating and patch wires on the review unit's main board.[5] After Tandy bought GRiD Systems in 1988, the machine was also sold as the GRiD 386mc.[1]
Specifications
[edit | edit source]| Item | Detail |
|---|---|
| CPU card | 80386 at 20 MHz with a 40 MHz oscillator, Intel 82385 cache controller and 32 KB of 35 ns static RAM; socket for a 20 MHz 80387 |
| Memory | Two proprietary 32-bit memory slots; each memory card holds eight SIMMs, 2 MB with 256K x 9 SIMMs or 8 MB with 1M x 9 SIMMs; 2 MB standard, 16 MB maximum; 100 ns DRAM |
| Main board | Intel 82306, 82307, 82308 and 82309 Micro Channel support chips; 82706 VGA with an INMOS IMSG176 RAMDAC; 82072 floppy controller; NS16550A UART; 8742 keyboard controller; Dallas DS1287A clock and DS1220Y non-volatile RAM |
| Slots | Five Micro Channel slots (two 32-bit, three 16-bit), two memory slots and the CPU card slot |
| Drives | 1.44 MB 3.5-inch floppy drive; room for a second 3.5-inch drive and two 5.25-inch devices; ST-506, ESDI or SCSI controllers for hard disks |
| Ports | DB-9 serial, DB-25 parallel (bidirectional), DB-15 VGA, keyboard and mouse |
| Power supply | 192 W, 105 to 130 V AC, 60 Hz; heat output 363 BTU/h |
| Size and weight | 6¼ x 15¹¹⁄₁₆ x 17 in and 28 lb (Radio Shack); 17 x 15½ x 6½ in and 26½ lb (BYTE) |
Sources: Radio Shack's specification sheet, Ardent Tool's board notes, the brochure and BYTE.[6][3][7][2][5]
Hardware
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The 80386, the cache and the coprocessor socket are on a CPU card (Tandy part 8709839) that plugs into a proprietary connector, J18, at one end of the main logic board (8899061). The two memory cards (8899065, catalogue 25-6030) plug into J8/J9 and J11/J12.[3] BYTE describes the CPU slot and memory slots as proprietary 32-bit slots.[2] Ardent Tool's notes and PC Magazine (as summarised by Wikipedia) describe one 16-bit Micro Channel slot, J14, as having the extra video extension contacts; an owner on the VCFed forum says the machine does not support the video extension and so cannot take 8514/A or XGA cards.[3][1][8]
The power supply connects to the main board on J7, a 12-pin connector: +5 V on pins 1, 2, 4 and 5, +12 V on pin 3, ground on pins 6 to 9, −5 V on pin 10, −12 V on pin 11 and Power Good on pin 12.[3]
Clock and configuration memory
[edit | edit source]The 5000 MC has no separate clock battery. The clock and CMOS RAM are in a Dallas DS1287A (U19) and the configuration is also held in a Dallas DS1220Y non-volatile RAM (U11); both chips contain their own lithium cell.[3][9][10] Radio Shack sold replacements as parts MX-1560 (U11) and MX-1561 (U19).[6] The settings are made with the reference diskette, which can also back the configuration up to disk and restore it after the CMOS battery fails.[11] Ardent Tool hosts an image of reference diskette version 1.02.03.[3]
Known faults
[edit | edit source]- The DS1287A and DS1220Y run flat with age, and the machine then needs its reference diskette before it will start normally; owners have described being stuck without one.[12][13]
- One owner's machine would not power on and looked like a power supply fault.[13]
See the Tandy 5000 MC Troubleshooting Guide.
Documentation
[edit | edit source]- File:Tandy 5000 MC Professional System brochure (Radio Shack).pdf: Radio Shack's sales brochure with the full specification table.
- Radio Shack's faxback service documents for the 5000 MC (specifications, settings, memory, reference diskette, pinouts, video modes, coprocessor, printer ports, beep codes and parts lists) survive as text copies at Ardent Tool of Capitalism.[3]
- Ardent Tool reports that the complete Tandy 5000 MC Technical Reference has passed to a collector; no scan of it has been found online.[3]
Related pages
[edit | edit source]- Tandy 5000 MC General Maintenance
- Tandy 5000 MC Troubleshooting Guide
- Tandy 5000 MC Capacitor Replacement Guide
- Tandy 4000
- Tandy 3000
- Floppy Drive Repair
References
[edit | edit source]- ↑ 1.0 1.1 1.2 "Tandy 5000 MC", Wikipedia (retrieved 2026-10-21). Announcement on 21 April 1988 and first shipments in the last week of July 1988, citing The New York Times; resale by GRiD as the GRiD 386mc.
- ↑ 2.0 2.1 2.2 2.3 2.4 Mark L. Van Name, "A PS/2 in Channel Only", BYTE, February 1989, pp. 197-202, scan at the Internet Archive. First vendor to ship a Micro Channel-compatible PC; specifications, slots, prices and reference disk.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 "Tandy 5000 MC", Ardent Tool of Capitalism (retrieved 2026-10-21). Main logic board 8899061 layout and parts, CPU board 8709839, memory board 8899065, power connector J7, switch S1 and S2 notes, and copies of Radio Shack's faxback documents 1721-1728, 2410 and 22041-22043.
- ↑ Radio Shack faxback document 22042, "250-6001 Tandy 5000 MC w/40 HD drive", detailed parts list, copy at Ardent Tool (retrieved 2026-10-21).
- ↑ 5.0 5.1 Eric Knorr, "Tandy 5000MC", The Hardware Shelf, PC World, April 1989, pp. 102-106, scan at the Internet Archive. Performance against the Model 70-121, prices, memory boards, jumpers and DIP switches, patch wires, FCC Class A.
- ↑ 6.0 6.1 Radio Shack faxback document 1721, "5000 MC (250-6000/1/2) Specifications", copy at Ardent Tool (retrieved 2026-10-21). Dimensions, weight, processor, slots, memory, cache, power supply, heat output, ports, BIOS version 01.02.04, battery replacement parts.
- ↑ Radio Shack, Tandy 5000 MC Professional System brochure, hosted as File:Tandy 5000 MC Professional System brochure (Radio Shack).pdf. Specification table on page 4.
- ↑ "Tandy 5000 - Radio Shack Product Announcement - April 21, 1988", Vintage Computer Federation Forums (retrieved 2026-10-22). Owner's comment that the video extension is not implemented.
- ↑ Dallas Semiconductor, DS1287 Real Time Clock data sheet, copy at Ardent Tool (retrieved 2026-10-22), page 1: self-contained subsystem including lithium energy source and quartz; over 10 years of operation without power.
- ↑ Dallas Semiconductor, DS1220Y 16K Nonvolatile SRAM data sheet, copy at Ardent Tool (retrieved 2026-10-22): self-contained lithium energy source; 10 years minimum data retention without external power.
- ↑ Radio Shack faxback document 1724, "5000 MC Utility: The Reference Diskette", copy at Ardent Tool (retrieved 2026-10-21).
- ↑ "Tandy 5000 MC", Vintage Computer Federation Forums, 2006-2007 (retrieved 2026-10-22). Owners looking for the reference diskette; flat CMOS battery after storage.
- ↑ 13.0 13.1 "Tandy 5000 MC, incomplete, non-working, on eBay", Vintage Computer Federation Forums (retrieved 2026-10-22). Machine that would not power on; reference diskette hard to find; replacement ROMs.