Settings

Screen

Phosphor

Green, amber or white. A tint on the emulated raster — the display is one bit deep, so this is simply the colour of "lit".

Screen shape

Original (800×1024, 88 columns) or Wide (1152×1024, 127). Changing it restarts the terminal, because the size is set during its power-on self-test. See the DMD 5620.

Scaling

Crisp rounds to a whole-number multiple so stipple patterns do not shimmer;Fill uses the whole window. Crisp falls back to filling below 1:1, where there is no whole number available.

Pointer speed

How far the emulated mouse moves for a given movement of yours. The 5620 integrates deltas from free-running counters rather than being told a position, so this is a feel setting rather than a precise one.

Glass terminals

Colours and text size

For the vt100 windows only. The 5620 is a raster and takes no part in this.

Log tty01 in automatically

On by default. The app watches for the login prompt on tty01 and logs in as your account. Turn it off if you would rather do it yourself, or want that line free.

Terminal

Terminal speed

How fast the emulated serial line runs. The default is well above 1985 — the wire is the one place where authenticity costs you a minute and a half of watching a progress-free download. Lower it if you want the period-correct experience.

Remember terminal settings

Keeps the 5620's non-volatile memory between launches, as the real one did. Off means it powers on factory-fresh every time.

Log wire diagnostics

Writes throughput and queue statistics beside the machine. For diagnosing the serial line; off unless you are asked for it.

Saved session

Shows whether a snapshot exists and when it was taken, and lets you discard it. Discarding means the next launch is a cold boot — which is slower, and occasionally what you want.

The snapshot and the disk are a pair. A snapshot describes a machine whose filesystem is in a particular state, and restoring one over a different disk would write stale metadata onto media it has never seen. The app keeps them together or discards them together; there is no third option, and this is why nothing here offers to delete just one.

Disk

Export

Writes the emulated machine's disk out as a file. It is a plain disk image — usable with SIMH on a desktop, and a perfectly good backup.

Import

Replaces the machine's disk with one you supply. Staged: it takes effect at the next launch, because swapping a disk under a running VAX is exactly as bad an idea as it sounds.

Reset

Puts back the disk the app shipped with. This erases everything inside the emulated machine — your files there, not on your Mac. Files on shared folders are on your Mac and are untouched.

Worth knowing: when an app update carries a newer system image, the working disk is replaced automatically at launch — no prompt, and Reset is not involved. An update is not a decision you should have to make. Reset stays yours and means something different.

Machine

Ethernet card (NI1010)

Adds or removes the network hardware. Off is a machine that never had a card, not a machine with networking disabled — and shared folders go with it, since they travel over the same emulated network. See networking.

Shared folders

Choose a folder for /n/macos, optionally offer your home folder at/n/home, and decide whether the machine may write to either. Full detail insharing files.