What sort of hw needed for Spectrum demos?

category: offtopic [glöplog]
Started hoarding more 8-bit stuff to the closets again :) What kind of hardware would be the optimal - and preferably somewhat available/affordable - combination for running ZX Spectrum demos? Apparently most of them require a 128k model. Real 128ks seem to be a bit on the expensive side, so would it hurt compatibility-wise to get a +2 or a +3? Another big issue is that there seem to be numerous different file formats for emulators etc. Demos seem to come mostly as .tap and .scl.

At the moment I'm considering getting some divIDE variant (there seem to be countless versions and countless firmwares for them, too) or a HxC Floppy Emulator, but have really little idea whether they would be enough to run everything. .taps can apparently be uploaded to a real Speccy by playing them as audio, but that won't cover the disk-based demos and requires a PC around. Any insights welcome!
added on the 2011-09-24 13:01:53 by Marq Marq
For russian demos, which are major amount of ZX demos, you need something Pentagon-compatible, with TR-DOS and without slow RAM. Most of them won't work correctly or at all on Sinclair/Amstrad models, even being converted from TR-DOS to tape (not always possible).
added on the 2011-09-24 13:18:17 by Shiru Shiru
It's unlikely that you'll find a TR-DOS machine for a reasonable (sub-100 Euro) price. I don't think the situation with Russian demo compatibility is quite as bad as Shiru suggests, though - it mostly affects releases from around 1997-2001, when demo parties were encouraging people to do increasingly Crazy Shit with the hardware, but the Russian scene was still fairly isolated and unaware of the importance of their demos running on 'western' Spectrums. There's still enough good stuff - old and new, from Russia and elsewhere - to make it worthwhile to buy a regular Spectrum.

I'd recommend looking out for a +2 with a light grey case - these are 99.9% functionally equivalent to the original 128 (the only difference is the ROM version, and I'm not aware of any demos that rely on that). The +3 and +2A (which says "Spectrum +2" on the case, but has a black case) have slightly different timings, which may affect stuff like multicolour effects, and some revisions of them have totally fucked-up sound output.

I'd definitely go for the original DivIDE (not the DivIDE Plus - there are some reported hardware bugs, and the extra features are not particularly relevant if you're mainly using it for demo watching), as sold by divide.cz, Lotharek and often other people on eBay. The Fatware firmware will give you a nice UI for loading .tap files. ESXDOS is expected to offer TR-DOS emulation at some point, for loading .trd and possibly .scl images (albeit only at a high level, so it won't work with certain Russian software that uses low-level tricks), but it's the usual "one guy in his free time" type of project, so don't hold your breath for any particular release date...

The other benefit of a +2 is that if you're feeling adventurous, you'll be able to fit Velesoft's Profi interface which enhances compatibility with Russian software - it's going into production over the next week or so, and I suspect it's about to become the Next Big Thing in the Spectrum world :-)
added on the 2011-09-24 15:33:39 by gasman gasman
Thanks for the tips. It seems there's no silver bullet, so probably need to get two machines to support everything. Will probably go with +2/divIDE and ZX Evolution.
added on the 2011-09-25 12:37:24 by Marq Marq