Sharp – PockEmul

LC-3 Compiler User Manual for SHARP PC-1261/PC-1262

This is a compiler for Pocket Computer created around 1987~1988.

Compiler and Runtime Library are very compact and can coexist in memory.
- You can edit, compile, and run source code in memory.
A lot of useful instructions for the game.
The generated code is small and fast because variables are stored in RAM.

I recently made PockEmul compatible with the LC-3 Compiler for the Sharp PC-1261/1262. It will be part of PockEmul 2.10.0

This required extensive groundwork, as the compiler relies heavily on undocumented features of the SC61860 processor, many of which had not yet been implemented in the emulator.

The compiler enables developers to write programs directly in BASIC, using special instructions, and then compile the code into LM format, all within the pocket computer itself.

It is particularly well-suited for creating fast-paced graphical games.

Originally developed in Japan, the compiler had no existing English documentation available until now.

To address this, I’ve translated the X thread by @poyokoma_danna, which details LC-3 functionalities, and supplemented it with a translation of the official documentation (hiroog/LC3_Compiler: LC-3 Compiler for SHARP PC-1261/PC-1262).

An SC61860 bug since 25 years

Incredible — a bug in the SC61860 CPU used in classic Sharp devices has been fixed after 25 years!

Usually, a CPU bug is spotted quickly because everything crashes. But this one was a subtle side effect in batch instruction processing.

When I requested a batch of 0xFF, the loop exited without doing anything, instead of executing 256 times.

Turns out, it was just a while () {} that needed to be replaced with a do {} while ().

Now, the LC-3 compiler works correctly — it’s the one that uses 0xFF batches, unlike the standard ROM which never does.

It took me ages to find this bug, I was so convinced my algorithm was solid. obviously, after 25 years of faithful service…

PockEmul 2.9.0 New Release

Dear PockEmul’s fans, we are pleased to announce the new PockEmul release. It will be available in the next few days.

This new version brings several new models and some new features:

New Casio VX-3, VX-4 and FX-870p package
New Casio Almost PB-100, Almost PB-300, FP-12 and FP-40 (SB-42) package.
New CE-15x extension for PC-1500 series.
New Sharp PC-E500Jap and PC-E500-BL.
New HP-10c.
New Search feature for Local and PockEmul Cloud storage.
Share a Cloud session by QRCode.
CE-1600p new pen head rendering.
Keyboard Simulator new layout and overclocking up to x100.
A new ‘Lock Position’ feature in the contextual menu that fixes the position of a device on the screen.
The XP-140 Monitor Card is available for the X-07.
A lot of bug fixes.