15Khz RGB to VGA Converter Scaler

[alexh]

It's not. This is a Cypress CM-397. We've had them apart. The chips inside are 16-bit only.

Not only is it 16-bit only. Cypress said the Digital->Analog->Digital->Analog conversion process had an effectiveness of 12-bit

[alexh]

Unless they've re-done the internals, which I doubt it.

[alexh]

HopperJF wrote:
I just bought one of these:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=180301378360

To use with my Acorn multisync monitor. I'm hoping it is alright but if it isn't, it was only £15 so no big deal.  :-)

Depends which Acorn Multi-sync monitor it is. AKF50 and AKF52 will work and AKF85 I think works too.

This is a purely passive device. Just wires. Also known as a Sync-Dongle.

http://bboah.com/cgi-bin/showhardware.cgi?HARDID=733

[alexh]

Correct.

Early Acorn monitors were made by the infamous monitor company Microvitec. Well known for making 15-31KHz multi-sync monitors. Later ones which came with RISCPC's were AFAIK standard PC monitors (i.e. 31KHz)

[alexh]

You'll never find a PC monitor which support 15KHz horizontal scan rate and 50Hz vertical refresh rate through the VGA socket.

LCDTV or Plasma would be a better way to go but remember you'll need to connect via the SCART socket.

[alexh]

HopperJF wrote:
Edit: I was told the Acorn monitor I have is multisync, I will go check the model number.

Multisync does not mean anything these days. All it means is the monitor is not a fixed frequency monitor. Back in the old days it meant it support 15KHz and 31KHz but now it could be 31KHz+.

Multisync no longer means a monitor supports 15KHz

[alexh]

http://acorn.chriswhy.co.uk/docs/Monitors/Acorn_AKF506070.pdf

As you can see from this document, AKF5x series supports 15KHz will work fine with a sync dongle and an Amiga.

[alexh]

It will however flicker enough to trigger an epilepsy seizure when displaying 50Hz interlaced modes. :-)

The flicker will be much more apparent than say a CRT TV using RGB SCART due to the low persistence phosphor of the monitor. (But it will also be a lot sharper!)