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yann64andClaude Opus 5.5 b274874139 All machines linked to their forum thread (full comment import)
1,289 discussions, 9,527 archived comments; pages no longer carry the comments themselves.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YDRjtmAiNpo5mK5N3d7QwZ
2026-10-13 17:26:43 +02:00

6.1 KiB

title, categories, types, origins, years, cpus, params
title categories types origins years cpus params
Sharp PC-1245
Computers
Pocket
Japan
1983
Sharp SC61860 CMOS 8-bit
name image company company_name specs tabs forum_thread photos emulators links related oc_id source
PC-1245 /media/museum/photos/sharp_pc1245_system_s1.jpg /companies/sharp Sharp
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NAME PC-1245
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MANUFACTURER Sharp
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TYPE Pocket
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ORIGIN Japan
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YEAR 1983
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BUILT IN LANGUAGE BASIC interpreter
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KEYBOARD 52 keys, QWERTY calculator type with numeric key-pad
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CPU Sharp SC61860 CMOS 8-bit
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SPEED 576 KHz
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RAM 2.2 KB - 1486 bytes available for BASIC programs
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ROM 24 KB
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TEXT MODES LCD display - 1 line x 16 char. 5x7 dot matrix
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GRAPHIC MODES None
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COLORS monochrome grey LCD
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SOUND CPU controlled piezo buzzer, fixed frequency and duration via BASIC statement
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SIZE / WEIGHT 135 (W) x 70 (D) x 9.5 (H) mm / 115 g with batteries
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I/O PORTS Proprietary 11-pin expansion bus
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BUILT IN MEDIA Memory safe guard
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POWER SUPPLY 6 volts, 2 x CR 2032 lithium cells
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PERIPHERALS CE-126P thermal printer\ CE-124 Tape recorder interface\ CE-125 Thermal printer and micro cassette recorder
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PRICE Unknown
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emulators
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1105
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LARGE VIEW /media/museum/photos/sharp_pc1245_system_s2.jpg
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BOTH SIDES LCD contrast button on the right side,\ 11-pin expansion connector on the left side. /media/museum/photos/sharp_pc1245_sides_s1.jpg
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BACK COVER /media/museum/photos/sharp_pc1245_back_s1.jpg
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WITH CE-125 INTERFACE /media/museum/photos/sharp_pc1245_ce125_s1.jpg
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CE-125 #2 The AC adaptor jack is used to recharge the internal battery. The Audio In jack allows an external tape recorder to be used to read programs. /media/museum/photos/sharp_pc1245_ce125_s2.jpg
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LOGIC CARD #1 **(1)** LCD contrast adjustment\ **(2)** CR 2032 cell connectors\ **(3)** 2 KB RAM chip\ **(4)** Buzzer leads\ **(5)** SC43536 display driver chipset\ **(6)** 11-pin expansion connector\ **(7)** SC61860 CPU\ **(8)** LH532920 ROM, holds the BASIC interpreter\ **(9)** Reset switch. /media/museum/photos/sharp_pc1245_pcircuit_s2.jpg
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LOGIC CARD #2 Keyboard and display side. Keyboard switches are covered with a rubber mask. /media/museum/photos/sharp_pc1245_pcircuit_s1.jpg
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USER'S MANUALS As usual with Sharp pocket manuals, the 1245 manual is very complete and detailed. /media/museum/photos/sharp_pc1245_manuals_s1.jpg
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POEMS http://sourceforge.jp/projects/poems/ Unix / Linux PC-12xx, 14xx & 13xx emulator
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PockEmul http://pockemul.free.fr/ Multiplatform Emulates nearly all Sharp pocket computers!
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Web Wiz CAPTCHA http://www.webwizcaptcha.com
/museum/sharp-pc-1210-1211-1212
/museum/sharp-pc-1250-pc-1251
/museum/sharp-pc-1260-pc-1261-pc-1262
/museum/sharp-pc-1401-pc-1402-pc-1421
/museum/sharp-pc-1403-h
/museum/sharp-pc-1500-pc-1500a
/museum/sharp-pc-2500
1135
url date
https://web.archive.org/web/20230608211319/http://www.old-computers.com/museum/computer.asp?c=1135 2023-06-08

Basically, the PC-1245 was a low-cost version of the PC-1251.

The following features were affected: First, it had only 2.2 KB RAM instead of 4 KB, thus only 1486 bytes were available for programming. Second, the display provided only 16 characters instead of 24. Third, the RESERVE mode, which had allowed to assign BASIC commands or functions to 18 of the alphanumeric keys, had been eliminated. Instead, these keys were assigned BASIC shortcuts for easier program entering.
As a cosmetical difference, the colour scheme of the keyboard had been reversed, that is the alphanumeric part was brown and the numeric keypad grey for the PC-1245.

Internally, the electronics were more or less the same, except for an updated ROM chip and the eliminated RAM chip. The SC61860 microprocessor, the display driver chip SC43536, the LH532920 ROM and one HM6116 2k x 8 RAM chip were all mounted on a single PCB. The 146 bytes of additional RAM were located in the display driver chip.

Needless to say, that the PC-1245 could use the same peripherals as the PC-1251: The CE-125 thermal printer and micro cassette recorder unit, the CE-126P thermal printer and the CE-124 tape recorder interface.

Seiko sold a slightly modified versions of the PC-1245, named MC-2200

Thanks to Roman von Wartburg and his site for information.

About the missing RESERVE-Mode, Joerg Lemmer clarifies:
There ist no Reserve-Position of the switch right to the display on the PC-1245, but you can assign programs to keys on the keyboard using the DEF-Key. Therefore you have to start a program like
10 "A": AREAD X: ...
This program will then be available in run-mode using , whereas the AREAD-command uses the already displayed value as input and assigns it to variable X. By this it is possible to use the PC-1245 in RUN-mode as a normal calculator and then use the result for a BASIC-routine. That is the main reason for me to have this nice little thing still on my desk.
I could write books about it and all the fun we (friends in school) had with this thing. We used it to cheat in tests, used undocumented commands to make music with it and even programmed some games.