# Disassembled source for DR Logo (CPC / PCW)

**URL:** <https://forum.cpcwiki.eu/t/disassembled-source-for-dr-logo-cpc-pcw/764>\
**Category:** Applications\
**Tags:** cpm, logo, pcw\
**Created:** [October 9, 2026, 11:51am UTC](https://forum.cpcwiki.eu/t/disassembled-source-for-dr-logo-cpc-pcw/764 "2026-10-09T11:51:45Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![JohnElliott](https://forum.cpcwiki.eu/user_avatar/forum.cpcwiki.eu/johnelliott/32/161_2.png) [@JohnElliott](https://forum.cpcwiki.eu/u/JohnElliott)\
**Post date:** [October 9, 2026, 11:51am UTC](https://forum.cpcwiki.eu/t/disassembled-source-for-dr-logo-cpc-pcw/764/1 "2026-10-09T11:51:45Z")

</div>

From time to time over the years I’ve fiddled about with disassembling DR Logo, and I’ve now got source that rebuilds to the original in two versions: one for the CPC, the other for the PCW. Rather than try to reconstruct the original C source and build scripts, it’s just a lot of assembly, most of it not commented. The main aim was to try and separate the machine-independent and machine-specific parts. The differences, and the source, can be found at [CP/M information archive : Digital Research LOGO](https://www.seasip.info/Cpm/drlogo.html)

While it was already possible port DR Logo to other CP/M 3 systems by taking the PCW version and replacing the RSX it uses to perform graphical functions, building from source allows more flexibility; for example, by adding system-specific primitives, or implementing functions which the PCW stubbed out rather than implementing through the RSX.