Back in the day (early 1990s) I remember connecting the output of a CGA graphics card to the 1084s, I think by building a custom cable for it, and using a secondary TTL input my specific 1084s had (not all of them have it). I no longer have this 1084s sadly.
But yes, I think SVGA refresh rates and resolutions are out of the question. If you really want to use the 1084s with something modern, your best bet would be a SVGA/HDMI to SCART/Composite converter. Depending on the version of the 1084s you have, you may need an additional scart-to-9-pin adapter (or round barrel adapter). IMHO it's too much hassle for what it's worth but can think of scenarios where it makes sense (physical space considerations, a preference for a CRT to use with emulators etc.).
