IBM Space Saving Keyboard matrix simulator (WIP)

This interactive tool simulates the key-matrix of a IBM Space Saving Keyboard so that you can test if possible key combinations work without needing to test on a physical keyboard. Model M keyboards are all fundamentally two-key rollover (2KRO) due to the use of a membrane assembly, but this doesn't mean Model Ms cannot register more than 2 keys unlike popular belief. This tool demonstrates this and can allow you to see if a given Model M key-matrix would be suitable for your needs.

Disclaimer & notes

This tool is intended to be a guideline only. The results from any input are based on physical key-matrix data only and doesn't take into account firmware (ie, differing deghosting algorithm implementations or bugs/quirks). If you're using this tool as part of a purchasing decision, if possible, it would be prudent to try verifying results on a real keyboard someone you know has or ask on /r/modelm subreddit. The tool is also best viewed on desktop.

Keyboard simulator (ISO)

Esc
F1
F2
F3
F4
F5
F6
F7
F8
F9
F10
F11
F12
Print Screen
Scroll Lock
Pause
`
1
2
3
4
5
6
7
8
9
0
-
=
Backspace
Insert
Home
Page Up
Tab
Q
W
E
R
T
Y
U
I
O
P
[
]
Enter
Delete
End
Page Down
Caps Lock
A
S
D
F
G
H
J
K
L
;
'
#
LShift
ISO \
Z
X
C
V
B
N
M
,
.
/
RShift
Up
LCtrl
LAlt
Space
RAlt
RCtrl
Left
Down
Right
Switch to ANSI​/US English

Only UK English functional layout is available for the ISO simulator at this time

Key

Firmware caution: A 3-key combination that may or may not be problematic depending on keyboard's firmware. A custom QMK-based controller would probably be fine with these, but IBM/Lexmark/Unicomp native firmware may not.
Hardware block: A N-key combination that will block in any circumstance due to the matrix's design. There is nothing you can do about these since they're a fundamental key-matrix limitation.

Matrix

This is a tabular representation of the data used by the simulator above. A keyboard matrix is constructed from a series of columns (X-axis) and rows (Y-axis) whose intersections are used for key assignment. Such matrices allows a large number of keys to be driven by relatively few traces, as opposed to each key requiring its own circuit.

0 1 2 3 4 5 6 7 8 9 A B C D E F
0 k_b k_space k_n KC_NO k_fwslash k_down k_right k_left k_ralt
1 k_rctrl k_rshift k_z k_x k_c k_v k_return k_m k_cm k_period k_nuhs k_pause
2 k_a k_s k_d k_f k_backsl k_j k_k k_l k_semicolon
3 k_q k_w k_e k_r KC_NO k_u k_i k_o k_p k_scrl
4 k_1 k_2 k_3 k_4 k_f10 k_7 k_8 k_9 k_0 k_f11 k_f12 k_pgdn k_end k_prscr
5 k_lctrl k_tild k_f1 k_f2 k_5 k_f9 k_6 k_equals k_f8 k_minus k_del k_ins k_pgup k_home
6 k_lshift k_tab k_caps k_f3 k_t k_backspace k_y k_squarebrcl k_f7 k_squarebrop
7 k_esc k_nubs k_f4 k_g k_f5 k_h k_f6 k_singlequote k_up k_lalt

More info