Tandy 1000 HD Troubleshooting Guide
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Most faults on the Tandy 1000 HD are diagnosed exactly as on the original Tandy 1000: the start-up self-test, the main board and the power supply are covered in the Tandy 1000 Troubleshooting Guide. The HD adds a 10 MB Tandon TM252 hard disk, a Western Digital WD1002S-WX2 controller and their cabling, which bring their own faults.[1]
Quick reference
[edit | edit source]| Symptom | Likely cause | Action |
|---|---|---|
| Machine asks for a system disk in drive A: or reports a boot failure | Cable to the internal hard disk upside down, or controller jumpers wrong | Check the 34-way card-edge connector at the drive and the SW1 jumpers.[2] |
| Drive select light on a hard disk comes on at power-on and stays on | Cable upside down at that drive | Turn off and reverse the cable.[2] |
| Drive does not spin up | No +12 V at the drive, or a supply that cannot deliver the start-up current | Measure +12 V at the drive during power-on.[3] |
| Drive works but transfers slowly | Formatted at an interleave of 5 | Reformat at interleave 4 after a full backup; see General Maintenance.[4] |
| Machine faults with no hard disk activity | Main board or supply fault | Follow the Tandy 1000 Troubleshooting Guide. |
Power to the drive
[edit | edit source]The TM252 needs +12 V within 10 percent and +5 V within 5 percent. At start-up it draws 2.0 A typical and 2.4 A maximum from +12 V for up to 12 seconds, then 1.4 A typical and 1.8 A maximum while running; on +5 V it draws 0.5 A typical and 0.8 A maximum. Tandon puts no restriction on the order in which the supplies come up.[3] Measure +12 V during power-on as well as once the drive is running. The HD's supply board is listed as part 8489073; the supplement gives no output ratings for it.[5]
Cables and jumpers
[edit | edit source]The WD1002S-WX2 sits in the expansion slot nearest the fan. It connects to the drive by a 34-way control cable and a 20-way data cable; on the controller, the internal drive's data cable goes on the connector nearest the control cable.[2] Jumper block SW1 on the controller, positions marked 1 2 3 4 8 7 6 5, is set in the 1000 HD with positions 2, 3, 4 and 5 fitted. Position 2 defines the internal drive as the 10 MB type; positions 3 and 4 define a second drive:[2]
| Type | Cylinders | Heads | Capacity | Positions jumpered |
|---|---|---|---|---|
| A | 512 | 8 | 30 MB | 3 and 4 |
| B | 306 | 4 | 10 MB | 4 |
| C | 306 | 6 | 15 MB | 3 |
| D | 612 | 2 | 10 MB | none |
The same note says a second drive must be jumpered as drive select 3 on the drive itself, must be hard-sectored with HSECT, partitioned with FDISK, and the machine reset with the reset button before HFORMAT is run.[2]
Software and BIOS
[edit | edit source]- The Tandy hard disk utilities are HSECT (low-level format), FDISK and HFORMAT; the HD speed-up note used HFORMAT from MS-DOS 2.11.22.[4]
- An owner recalls that Radio Shack advised that the original Tandy MS-DOS 2.11 for the 1000 did not support hard drives, and that a DOS upgrade was needed.[6]
- The Tandy 1000 FAQ lists 01.01.00 as both the original and the latest BIOS for the 1000 HD.[7]
Replacing the hard disk
[edit | edit source]One owner whose MFM drive failed fitted an XT-IDE adapter with a CompactFlash card in its place.[8] A replacement MFM drive must match one of the drive types the controller's SW1 jumpers can select.[2] General MFM drive repair is on Hard Drive Maintenance and Repair.
Related pages
[edit | edit source]- Tandy 1000 HD
- Tandy 1000 HD General Maintenance
- Tandy 1000 HD Capacitor Replacement Guide
- Tandy 1000 Troubleshooting Guide
- Hard Drive Maintenance and Repair
References
[edit | edit source]- ↑ Radio Shack, Tandy 1000 HD Service Manual, catalogue no. 25-1001, Tandy Corporation, 1986, hosted as File:Tandy 1000 HD Service Manual (25-1001, 1986).pdf. Contents and Introduction, p. 1.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 "Adding a second (external) hard drive to the Tandy 1000HD", t1khd.txt, TVDog's Tandy 1000 archive (retrieved 2026-10-21).
- ↑ 3.0 3.1 Tandon Corporation, TM252 Rigid Disk Drive product specification, document 179050-001 Rev. B, Table 2.1 "Power Requirements", p. 2-2, reprinted in the Tandy 1000 HD Service Manual (25-1001).
- ↑ 4.0 4.1 "Tandy 1000HD Hard Disk SpeedUp", hdisinf.txt, TVDog's Tandy 1000 archive (retrieved 2026-10-21).
- ↑ Tandy 1000 HD Service Manual (25-1001), "Tandy 1001 Main Logic Main Assembly", p. 31.
- ↑ "Upgrading the Tandy 1000 BIOS ROM to v1.01", Vintage Computer Federation forum, March 2026, thread. Post by vwestlife, 26 March 2026.
- ↑ Jeff Hayes, "Tandy 1000-series FAQ", version 2.52, 25 October 2005, TVDog's Tandy 1000 archive (retrieved 2026-10-21). Section III.E.2.
- ↑ "Tandy 1000 model 25-1002", Vintage Computer Federation forum, January 2024, thread. Post by seaken, 8 January 2024.