Re: Booting DOS system with Arcade Monitor on OK?


[ Follow Ups ] [ Post Followup ] [ Build Your Own Arcade Controls message board ] [ FAQ ]

Posted by MrTomcat on 8, 2001 at 10:54 AM:

In Reply to: Booting DOS system with Arcade Monitor on OK? posted by webjester on 7, 2001 at 6:58 PM:

: Hey folks,

: Just bought a Konami 29" sit-down style cabinet, and am getting read to MAMEify it (leaving the original JAMMA goodness intact no less).

: Question though is, once everything is wired up properly, will it be safe to boot the DOS box with the Arcade Monitor on?

: I've read through the FAQ's that i've found, but haven't seen that specific issue addressed. Are the BIOS/DOS refresh rates and frequencies safe for the monitor, or am I better off rigging two power switches into the box, one for the monitor and one for the system?

Its a gamble....I've heard of PC monitors dying when their sync frequency has been driven too high. Generally I would say standard VGA frequencies are not safe for arcade monitors. You certainly won't be getting a recognisable picture (probably just a high pitched whistle).

Some of the responses to your query suggest using ARCMON.SYS to force safe frequencies from bootup, but the thing is this only comes into effect when your PC starts booting from the HD. Up until that point when your Pc is doing its memory/cpu/hd checks immediately following power on, you will still be getting VGA (e.g. too high) frequencies to your monitor.

Your 2 power switch idea is one possible solution, but there is a more elegant one. It requires a little soldering expertise, but essentially you build a small circuit that plugs into the printer port and sits between the rgb+sync outputs from your PC and arcade monitor.
An electrical path is only made between the two when a certain byte is written to the parallel port. This byte is only written once the PC is outputting arcade monitor friendly frequencies...e.g. once your PC has booted your game selector front end. ArcadeOS supports this.

Chris.


Follow Ups:



Post a Followup

Name:
E-Mail:

Subject:

Comments:

Optional Link URL:
Link Title:
Optional Image URL:


[ Follow Ups ] [ Post Followup ] [ Build Your Own Arcade Controls message board ] [ FAQ ]