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[sigma7]

Attached is a schematic of the Twiggy Digital Board, updated from Rev C to Rev H1 by reverse engineering.

This version is designated H1 to distinguish it from an original Rev H schematic; the board itself is labeled 'H'.

Note this is the Lisa variety of the digital board, the Mac variety is different.

Errata:

• C20 should be 1. uF
• R66 on Rev H1 is shown connected to a power rail, but the +5V designation is missing.
• F3 LM2917 is actually at F1

edit: added Errata

[sigma7]

Found this image of the Twiggy Digital Board Schematic Rev F

Observed differences from the reverse engineered Rev H1:

R24 is 10K on Rev F, 10 ohms on Rev H1
R31 is 10K on Rev F, 10 ohms on Rev H1

+5 Sense on Rev H1 is named +5V Monitor on Rev F

Capacitor on underside of board connecting LM2917-3 to LM2917-5 is designated C17 on Rev. F vs C on Rev H1.

All capacitors on the Rev F schematic are drawn with a curved plate, including non-polarized caps, and the orientation for polarized caps is not consistent (eg. curved side of C4 is +). (Rev. H1 and other Lisa schematics typically only have a curved side if they are polarized, and the curved side is the negative terminal)

The LM2917 is designated F1 on Rev F, F3 on Rev H1
The CD4015 is designated D1 on Rev F, E1 on Rev H1