@4kToaster
How do you plan to use your A4000? If you only want to play games on it from yester-year, you could get away with a TV modulator (aka the A520) easily obtainable from eBay. These take the Amiga's analogue RGB and output a (crappy) composite signal. There are mods on the internet that upgarde this to S-Video output, for a sharper image, useful for todays TVs. An Alternative to TV/modulator is one of the traditional Commodore 1080/1081/1084/1084s monitors which feature in almost all Amiga print or film/video advertising. These run at 15kHz and will probably leave you wondering if you have tinnitus :-D
If you want to use it with a standard PC monitor, you should keep in mind that the A4000 (or AGA Chipset) can only 'promote' certain display modes to a VGA compatible (31kHz) signal (and those usually only after workbench is up and running). If you want to run any of the more common Amiga display modes (eg during boot, or playing games etc), you'll need a scan doubler (SD), which preferably is also a flicker fixer (FF).
I believe the best way is to get a SD/FF and use it in combination with an LCD TV which has both RGB or S-Video 15 kHz in and VGA in. That way you only need one display, and you switch between the inputs on the LCD TV.
The AGA chipset is 'limited' to 256 colours from ~16-million when NOT using the 'static' HAM modes (ie most games, workbench etc)so if you want hi-colour, another route you might take is to buy a (very expensive) ReTargetable Graphics (RTG) video card. Names such as Picasso, GVP EGS Spectrum, and CyberVision are all included in this group. They are basically 'PC' video chipsets that allow Amigas to use hi-colour displays for the workbench environment (using a feature of WB3.x and above, and a relevant driver). Some of the better cards include a SD/FF, while most (all?) of the others include a pass-thru port. This allows 'multi-sync' monitors which are capable of displaying 15kHz - 31kHz images (see below for a couple of models) to use just a single port, or to pass in a scan doubled signal from a separate SD/FF, which can then also display on just one monitor.
A final alternative is to mod your A4000 and put it in a tower, then buy an after-market PCI busboard and use PCI display cards, such as the venerable 3Dfx VooDoo cards or ATi Radeon 9000 series cards, and some others. This is even more expensive, as the custom case and PCI busboard are usually around $Aus500 each, and you'd still want a SD/FF as these PCI cards only 'work' once workbench is running and the drivers are loaded. On the other had, this allows you to use more commonly available PCI cards like 10/100 NICs and TV Tuner cards, and NOT have to go hunting around for the esoteric and uncommon (read: very expensive) Amiga specific hardware. (Edit: You cn get a PCI busboard which fits into the A4000 desktop case, negating the need for an expensive custom tower case, but it's still expensive.) You may need a more powerful (custom/hacked) PSU for use with a PCI busboard and expansion cards also. Depending on what your Amiga has in it already, a CPU Upgrade (accelerator) might be necessary when using such a setup also.
A simple 23-pin <-> 15-pin converter won't do much for you, unless you have a monitor capable of 15kHz - 31kHz. Like the NEC 3D Multisync (and others in the family), the Commodore 1940/1942 or 1960 and others of their ilk.
Regards,
tiffers
