TRS-80 PC-7
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| Tandy PC-7, opened out, with the error-code list printed in the lid (photograph Pocket Museum) | |
| Specifications | |
|---|---|
| Manufacturer | Casio, for Radio Shack (Tandy Corporation) |
| Type | Pocket computer |
| Released | 1986 |
| Intro price | US$69.95 |
| CPU | One HD61747B16, CMOS (Kaiser) |
| Memory | 2 KB, 1,568 bytes free for programs |
| Storage | None |
| Display | 12-character LCD |
| Sound | — |
| Power | Two CR2032 lithium cells |
| Dimensions | 139.5 × 87 × 13 mm closed; 139.5 × 180.5 × 10.4 mm open |
| Weight | 146 g with batteries |
| OS / Firmware | BASIC |
| Predecessor | TRS-80 PC-4 |
| Model no. | 26-3673 |
The TRS-80 PC-7, sold as the Tandy Pocket Scientific Computer PC-7, catalogue number 26-3673, is a folding pocket computer that Tandy introduced in 1986 at US$69.95. It is a modified Casio FX-5200P: Casio's model has 1 KB of RAM and a slot for a 1 KB OR-1 pack, and Tandy had Casio fit the second kilobyte on the board, giving 2 KB as standard. Casio does not appear to have sold that version under its own name.[1][2] It has a 12-character display, the TRS-80 PC-5's BASIC with its mathematics and statistics functions, and no expansion port of any kind.[1]
History
[edit | edit source]Kaiser describes the PC-7 as Tandy's replacement for the TRS-80 PC-4 in the low-price slot, combining the PC-4's slow processor, small screen and small memory with the folding case and part-membrane keyboard of the PC-5 and PC-6. It stayed on sale until 1990, longer than the TRS-80 PC-8 that followed it.[1]
The PC-7 is the only model in the line with an alphabetically ordered keyboard. The letters are on a membrane panel in the lid, with the list of error codes printed above them.[1][3]
Hardware
[edit | edit source]Kaiser describes the PC-7 as a cut-down PC-5: one processor instead of two, the PC-4's 12-character LCD, and no memory backup cell. Because the input/output support was in the second processor of the PC-5, the PC-7 has no port for a printer or cassette interface, and programs cannot be saved.[1] Inside there is an empty memory slot, where the FX-5200P takes its OR-1 pack.[1]
Sources differ on the processor. Kaiser lists an HD61747B16; the Pocket Museum gives the Casio FX-5200P the same HD61913A01 as the PB-100 (PC-4), and lists the PC-7's processor only as "VLSI specific".[1][2] No service manual for the PC-7 or the FX-5200P is available to settle it.
The PC-7 runs from two CR2032 lithium cells.[2]
Error codes
[edit | edit source]The PC-7 shows errors as a number. The list printed in the lid reads:[2]
| Code | Meaning |
|---|---|
| 1 | Memory overflow |
| 2 | Syntax error |
| 3 | Mathematical error |
| 4 | Undefined line number |
| 5 | Bad subscript |
| 6 | Variable error |
| 7 | Nesting error |
| 8 | Password error |
Known problems
[edit | edit source]Kaiser found the PC-7's folding case weaker than the PC-5's: all but his new-old-stock unit showed flex strain at the join, and some had torn open there, exposing the ribbon cable that links the two halves and that is stressed by the distortion.[1] With no backup cell and no way to save to tape, everything in memory is lost when the cells are changed.[1]
Documentation
[edit | edit source]No Tandy or Casio service manual or owner's manual for the PC-7 is held by the Floodgap archive or the Internet Archive. The nearest hosted documentation is the PC-4 service manual, for the display type the PC-7 shares, and the PC-6 service manual, for the HD61747 family.[1]
Repair guides
[edit | edit source]- TRS-80 PC-7 General Maintenance – cells, the hinge and ribbon cable, keyboard
- TRS-80 PC-7 Troubleshooting Guide – symptoms, error codes and the nearest manuals
- TRS-80 PC-7 Capacitor Replacement Guide – what is known of the board
Related pages
[edit | edit source]- TRS-80 Pocket Computer – the whole Tandy pocket computer line
- TRS-80 PC-4, TRS-80 PC-5 and TRS-80 PC-6 – the other Casio-built models
- Battery Explosion, Capacitor or Corrosion Damage
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 Cameron Kaiser, "Tandy Radio Shack Pocket Computer PC-4 and Tandy Pocket Scientific Computer PC-5, PC-6, PC-7", Floodgap Retrobits, Tandy! Pocket! Mania!. Retrieved 2026-10-21. PC-7 section: 26-3673, introduced 1986 as a modified Casio FX-5200P at US$69.95; HD61747B16 CPU; 12-character LCD; 1,568 of 2,048 bytes free; folded and open sizes and 146 g; the OR-1 memory built in, leaving an empty slot; one CPU, the PC-4's LCD and no battery backup; BASIC with the PC-5/6 mathematics and statistics but no Data Bank or assembler; no expansion port, so no printer or tape; flex strain at the join and torn cases exposing the ribbon cable; the membrane alphabetic keyboard; on sale until 1990.
- ↑ 2.0 2.1 2.2 2.3 Pocket Museum, "The Tandy PC-7 computer (26-3673)" and "The Casio FX-5200P computer". Retrieved 2026-10-21. PC-7: 2 KB RAM, 1,568 bytes available, one line of 12 characters, no sound, 180 × 140 × 10 mm opened, 146 g, two CR2032 cells, no extensions. FX-5200P: 1 KB RAM (2 KB with one OR-1 card), 544 or 1,568 bytes available, 12 KB ROM, HD61913A01 CPU, two CR2032 cells.
- ↑ Wikipedia, "Tandy Pocket Computer", sections "Purpose" and "Other notes". Retrieved 2026-10-21. The PC-7's rectangular, alphabetically ordered keyboard and the error-code list printed above the text keypad; the Casio-derived PC-4 to PC-7 sharing one BASIC line.