[et_pb_section fb_built=”1″ _builder_version=”4.5.3″ _module_preset=”default”][et_pb_row _builder_version=”4.5.3″ _module_preset=”default”][et_pb_column type=”4_4″ _builder_version=”4.5.3″ _module_preset=”default”][et_pb_text _builder_version=”4.5.3″ _module_preset=”default” hover_enabled=”0″]<\/p>\n
A remake of the EA 2650 mini system<\/p>\n
In May 1978, Electronics Australia described a small development board based on the Signetics 2650 microprocessor. For many people in Australia (the author included), this was the first computer that was cheap enough to buy and build even if you were a student or beginner.<\/p>\n
This update to the simple and elegant design of the original provides a new PCB that evokes the original while adding modern alternatives to some of the hard-to-get parts of the original.
The original article text is included at the end of this document<\/p>\n
The new board has three options over the original.
\u2022 A crystal oscillator instead of the original monostable circuit.<\/p>\n
\u2022 A 2716 or 2732 EEPROM instead of the hard to get PIPBUG mask programmed device<\/p>\n
\u2022 An external 5V DC supply instead of a centre-tapped transformer<\/p>\n
\u2022 A TTL serial interface instead of 20mA current loop<\/p>\n
A short description of the PipBug system<\/p>\n
The debug\/monitor program, code by DAVID EDWARDS named \u201cPipbug\u201d, is resident in a 2608 ROM. Pipbug recognizes seven basic commands, each of which consists of an alphabetic character, any required numerical parameters, and a terminating return.<\/p>\n
The parameters are given as hexadecimal characters, with leading zeros unnecessary.
The seven commands and their functions are as follows:<\/p>\n
<\/p>\n
A \u2014 See and alter memory;
B \u2014 Set breakpoint (2 permitted);
C \u2014 Clear breakpoint;
D \u2014 Dump memory to tape;
G \u2014 Go to address, run;
L \u2014Load memory from tape;
S \u2014 See and alter registers.<\/p>\n
[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_2,1_2″ _builder_version=”4.5.3″ _module_preset=”default”][et_pb_column type=”1_2″ _builder_version=”4.5.3″ _module_preset=”default”][et_pb_image src=”https:\/\/www.vintagevibe.co.nz\/wp-content\/uploads\/2025\/04\/inside.jpg” title_text=”inside” _builder_version=”4.5.3″ _module_preset=”default” hover_enabled=”0″][\/et_pb_image][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.5.3″ _module_preset=”default”][et_pb_image src=”https:\/\/www.vintagevibe.co.nz\/wp-content\/uploads\/2025\/04\/running-1.jpg” title_text=”running” _builder_version=”4.5.3″ _module_preset=”default” hover_enabled=”0″][\/et_pb_image][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.5.3″ _module_preset=”default” hover_enabled=”0″][et_pb_column type=”4_4″ _builder_version=”4.5.3″ _module_preset=”default”][et_pb_image src=”https:\/\/www.vintagevibe.co.nz\/wp-content\/uploads\/2025\/04\/image.png” title_text=”image” _builder_version=”4.5.3″ _module_preset=”default” hover_enabled=”0″ align=”center”][\/et_pb_image][et_pb_text _builder_version=”4.5.3″ _module_preset=”default” hover_enabled=”0″]<\/p>\n
The Remake of the 2650 Mini System<\/p>\n
[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.5.3″ _module_preset=”default”][et_pb_column _builder_version=”4.5.3″ _module_preset=”default” type=”4_4″][et_pb_image src=”https:\/\/www.vintagevibe.co.nz\/wp-content\/uploads\/2025\/04\/Orginal-System.png” _builder_version=”4.5.3″ _module_preset=”default” title_text=”Orginal System” align=”center” hover_enabled=”0″][\/et_pb_image][et_pb_text _builder_version=”4.5.3″ _module_preset=”default” hover_enabled=”0″]<\/p>\n
Original 2650 Main board<\/p>\n
[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"
[et_pb_section fb_built=”1″ _builder_version=”4.5.3″ _module_preset=”default”][et_pb_row _builder_version=”4.5.3″ _module_preset=”default”][et_pb_column type=”4_4″ _builder_version=”4.5.3″ _module_preset=”default”][et_pb_text _builder_version=”4.5.3″ _module_preset=”default” hover_enabled=”0″] A remake of the EA 2650 mini system In May 1978, Electronics Australia described a small development board based on the Signetics 2650 microprocessor. For many people in Australia (the author included), this was the first computer that was cheap enough to buy […]<\/p>\n","protected":false},"author":2,"featured_media":661,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[7],"tags":[],"class_list":["post-658","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-vintage-computers"],"_links":{"self":[{"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/658","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=658"}],"version-history":[{"count":6,"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/658\/revisions"}],"predecessor-version":[{"id":1649,"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=\/wp\/v2\/posts\/658\/revisions\/1649"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=\/wp\/v2\/media\/661"}],"wp:attachment":[{"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=658"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=658"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vintagevibe.co.nz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=658"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}