View Full Version : Compaq Portable EGA/VGA CRT

August 1st, 2017, 08:14 AM
Is it possible to upgrade and replace the crt in the portable so as to add color? I know that the VDU card by defualt has cga emulation, and that there was an ega emulator card that would work with it,(https://books.google.com/books?id=Y01EX9nPrTwC&pg=PA50&lpg=PA50&dq=hercules+in+compaq+portable&source=bl&ots=RRJwtl_QV0&sig=CS9faFRagAYtELPZaiWvJSkFU1I&hl=en&sa=X&ved=0ahUKEwjV76jlsrbVAhVm5YMKHR6bAq4Q6AEIVjAL#v=on epage&q=hercules%20in%20compaq%20portable&f=false) but has anybody ever tried to upgrade the crt? What would that entail?

August 1st, 2017, 09:07 AM
That card would have used the existing Compaq Portable CRT and CRT circuit board. The Compaq Portable contains what is essentially a MDA/Hercules Monochrome monitor but it can also sync CGA video. The Compaq Portable proprietary video card makes use of this by displaying text mode in a higher resolution, and then switching down for graphics modes.

That card in the ad supports translating EGA images to MDA/Herc compatible output. So in the case of the Compaq Portable, one would just yank out Compaq's CGA card and plug in this one instead.

At any rate, at minimum you would have to find a CRT (or LCD flat panel display) that fits, as well as stuff in the CRTs associated circuit board (less of an issue for a flat panel). You would need to be aware of the machine's heat and power constraints. Beyond that, the Compaq Portable motherboard probably should accept any EGA or 8088 compatible VGA card.

August 1st, 2017, 02:56 PM
A couple of the ATI EGA Wonder cards have pins for the connectors to the IBM 5155 and Compaq portable's internal monitors. (Some budget versions released later removed the pins) It works by converting the EGA to greyscale for the monitor. I have one for my 5155 and it works great and the documentation mentions jumper settings for the compaq portable monitor. But yes, it's still greyscale.

Never heard of someone upgrading the CRT.... I think making it work properly with the PSU would be one of the harder parts. The other hard part would be making the monitor fit... everything's quite tightly packed in there. If you did all that work, you'd probably use a standard VGA connector to connect to it.