Base Junior computer, quite a small system: PCB 80089-1,-2,-3.
Equivalent to a KIM-1 without serial TTY and cassette interface: keypad, 6 seven segment LEDs, 1K ROM (2708), 1k RAM (2x 2114). Partial memory decode as in the KIM-1: first 8K block mirrored in memory.
Subtle differences in the ROM and hardware (RIOT 6532 versus RRIOT 6530: I/O and RAM at $1Axx instead of $17xx).
The monitor in ROM is quite similar and inspired by the KIM-1 monitor, but not identical.
(from Book 2, in Micro Ade format
Have a look at the Elektor Articles and Books page for a mullti-lingual overview of all publications on Elektor/Elektuur Junior and more.
PCB layout front (from March 1980 Elektuur article)
Note that this layout is not as shipped, the Junior PCB’s were front/back swapped. The book is correct.
PCB layout front (from Junior Book 1, as shipped)
PCB layout back (from March 1980 Elektuur article)
PCB layout back (from Junior Book 1, as shipped)
LED display PCB and layout
Photo of (stripped clean) PCB front
Photo of (stripped clean) PCB back
CPM-65, a CP/M-80 analogue operating system for 6502 based microcomputer Dietrich Lausberg build a Junior long ago an...
This source for an enhancement of the KIM-1 contains Jim Butterfield's Supertape and some other utilities and code. The...
A thesis by Jian - Xiong Shao, 1983, titled OUP/M - A 6502 Operating system, contains a floppy disk based operating syst...
This is a replica PCB made with KiCAD. This board is not a 100% accurate replica, because the added directly on the P...