Sharp PC-1251 Documentation
The Sharp PC-1251 documentation consists of two Sharp documents for the Sharp PC-1251 and the PC-1250: the service manual that covers both models, and the PC-1251 instruction manual.
Service manual
[edit | edit source]The Service Manual, Model PC-1251, PC-1250, code 00ZPC1251//E, was printed in Japan in December 1982 by Sharp's Industrial Instruments Group, Reliability & Quality Control Department, at Yamatokoriyama. The hosted copy is a 20-page scan from Sharp Pocket Computers.[1][2]
Contents
[edit | edit source]| Section | Printed page | PDF page |
|---|---|---|
| Cover and contents; the difference between the PC-1250 and PC-1251 | 1 | |
| 1. Products outline, 2. Specification, key and system layout | 1 to 2 | 2 to 3 |
| 3. System block diagram | 3 | 4 |
| 4. CPU internal block diagram and terminal descriptions (SC61860A02) | 4 to 6 | 5 to 7 |
| 5. LCD drive circuit and timings (SC43536), LCD power supply | 7 to 8 | 8 to 9 |
| 6. Service precautions | 9 | 10 |
| 7. Circuit diagram | 10 | 11 to 12 |
| 8. Parts and signal position (board drawings) | 11 to 13 | 13 to 17 |
| 9. Parts list and parts guide (exploded view) | 15 to 16 | 18 to 19 |
What it does not contain
[edit | edit source]- The scan has no printed page 14. The parts list on PDF page 18 begins part-way through the alphabetical list, at the 11-pin connector, so the entries before it are missing.
- The parts list gives no circuit designators, so capacitors and resistors are identified by value only.
- There is no disassembly procedure and no adjustment procedure beyond the display quality check in the service precautions.
Figures it settles
[edit | edit source]- Current consumption at a 5.8 V supply: 400 µA maximum on, 45 µA maximum off, after an all reset (page 9).
- The two polarised capacitors, 3.3 µF 10 V and 1 µF 6.3 V (circuit diagram and parts list).
- The PC-1250's program and data area is 2048 bytes smaller than the PC-1251's, and the two take different memory module boards.
Instruction manual
[edit | edit source]Sharp's English PC-1251 instruction manual (230-page scan) covers the keys and display, the ALL RESET button, cell replacement, use as a calculator, BASIC, the CE-125 printer and microcassette recorder (chapter 7), troubleshooting, maintenance, and appendices including the nine error messages and the specifications (appendix G, printed page 173).[3]
Pages that cite these documents
[edit | edit source]- Sharp PC-1251: specifications, parts, power and peripherals.
- Sharp PC-1251 General Maintenance: cells, reset, contrast, cleaning and the CE-125.
- Sharp PC-1251 Troubleshooting Guide: troubleshooting table, current limits, service precautions.
- Sharp PC-1251 Capacitor Replacement Guide: the two polarised capacitors.
- Sharp PC-1245 and its guides, for comparison with the related PC-1250 board.
Files
[edit | edit source]
Download: Sharp PC-1251 Service Manual.pdf · Sharp PC-1251 Instruction Manual.pdf
References
[edit | edit source]- ↑ 1.0 1.1 Sharp Corporation, Service Manual, Model PC-1251, PC-1250, code 00ZPC1251//E, December 1982: cover and contents (PDF page 1), back cover (PDF page 20). File:Sharp PC-1251 Service Manual.pdf.
- ↑ Sharp Pocket Computers, Printers, Cables, Level Converters & Accessories, sharppocketcomputers.com—link(accessed 2026-10-21) PC-1250/PC-1251 row: Sharp PC-1250/PC-1251 Service Manual and PC-1251 Operation Manual.
- ↑ Sharp, PC-1251 instruction manual, table of contents (PDF pages 3 to 5). File:Sharp PC-1251 Instruction Manual.pdf.