Tandy 102 Service Manual

The Tandy Service Manual: Tandy 102 Portable Computer covers catalogue number 26-3803, the Tandy 102. It was custom manufactured for Radio Shack, a division of Tandy Corporation, and printed in Japan; the copy here carries no date or manual part number. The hosted PDF has 111 pages and a text layer. It is a 2006 CD reproduction by Archive CD Books Australia: the first page is the CD's navigation page and the remaining 110 are the manual.

Contents

With the printed page numbers from the manual's own contents list:

• Part I, Introduction: system overview and external views (pp. 1-2 to 1-4), internal view with the main board drawing (p. 1-5) and LCD board (p. 1-6), specifications (pp. 1-7 and 1-8)
• Part II, Disassembly: cases, keyboard and LCD boards (p. 2-1), main board (p. 2-2)
• Part III, Maintenance: cleaning the body and LCD (p. 3-1)
• Part IV, Theory of operation (from p. 4-1): CPU and memory (p. 4-3), address decoding and bank selection, I/O map, keyboard, cassette, printer, bar code reader, buzzer, system bus, clock, serial interface, RS-232C and modem (including the modem transmit level adjustment), LCD, and the power supply, low-power detection and reset circuits (pp. 4-24 and 4-25)
• Part V, Troubleshooting: guidance and the troubleshooting guide flowchart (pp. 5-1 and 5-2), checking procedures for 12 functions (pp. 5-3 to 5-10), check list with a test program (p. 5-11)
• Part VI, Exploded view (p. 6-1), electrical parts lists for the main board (pp. 6-2 to 6-7), LCD board (p. 6-8) and keyboard (pp. 6-9 and 6-10), mechanical and assembly parts list (p. 6-11)
• Part VII, Schematic diagram of the main board (p. 7-1) and board views (from p. 7-3)
• Appendix A, Installation of optional RAM and ROM (p. A-1)
• Appendix B, Keyboard layout, connector pin assignments and character code table
• Appendix C, Technical information on the 80C85A, 81C55 and 6402, and the construction of the LCD

What this manual does not contain

The parts lists give values, tolerances and Radio Shack and manufacturer part numbers, but no temperature ratings for the electrolytic capacitors. The troubleshooting section names the parts to check for each fault and gives few measurements beyond the supply rails, the reset levels and the clock frequencies. There are no adjustment procedures apart from the modem transmit level.

Some printed details disagree with each other. The parts list gives C92 as 0.047 µF, but its part numbers (CC-474MJAP, CEVGR47ALX) and the schematic give 0.47 µF. The schematic marks C82 and C83 as 10 V parts where the parts list gives 25 V and 16 V, marks C103 as 16 V where the list gives 10 V, and shows an electrolytic C101 (1 µF) that the list gives as "not used". On the main board drawing (Fig. 1-4) the callout "Potentiometer VR1 for MODEM Transmitting Level" points to the part marked VR2, which the parts list gives as the modem control; VR1 is the contrast control. The manual does not cover the TRS-80 Model 100 or the Tandy 200.

Pages that cite this document

• Tandy 102: specifications, boards, memory, power supply, memory backup battery
• Tandy 102 General Maintenance: disassembly, cleaning, battery, modem adjustment, optional RAM and ROM, check list
• Tandy 102 Troubleshooting Guide: the checking procedures and check list
• Tandy 102 Capacitor Replacement Guide: the electrolytic capacitor values from p. 6-2

Download: Tandy 102 Service Manual (26-3803).pdf