[BUG]Amstrad PC1640 Video

Discussion of development and patch submission.
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jvernet
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Joined: Wed 31 Jan, 2018 9:49 pm

[BUG]Amstrad PC1640 Video

Post by jvernet » Fri 02 Feb, 2018 8:26 am

Hello,

When I select Amstrad PC 1640, config panel don't let me choose EGA (as it should automatically done), but only a grayed CGA box. I need to select any AT configuration, choose EGA, then fall back to PC 1640.

PC1512 do not let choose 8086 speed (only 8086/8).

There is no way to change DIP setting af the Emulated Amstrad (change language, for example).

nerd73
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Re: [BUG]Amstrad PC1640 Video

Post by nerd73 » Thu 15 Feb, 2018 11:07 pm

The config panel not letting you choose EGA is not a bug, as it's locked to EGA no matter what is selected beforehand.

jvernet
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Re: [BUG]Amstrad PC1640 Video

Post by jvernet » Thu 22 Feb, 2018 3:09 pm

It's locked on CGA. And only emulate CGA if you stay like that.

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SarahWalker
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Re: [BUG]Amstrad PC1640 Video

Post by SarahWalker » Thu 22 Feb, 2018 5:33 pm

It will be emulating the PC1640's onboard EGA, regardless of what is displayed in the video menu.

Zup
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Re: [BUG]Amstrad PC1640 Video

Post by Zup » Fri 23 Feb, 2018 7:42 am

How about displays?

AFAIK, PC1640 was sold with three displays: MD (monochrome), CD (colour), ECD (EGA colour). I'm not sure about it, but I guess that MD and CD were CGA monitors (so they couldn't display EGA modes). Maybe the card is not "locked" (you could try to start EGA modes with any display), but it seems that any MD display would at least thrown out of sync.

In this page, John Elliot shows different values for dip switches on PC1640 mainboard (funny, it seems that there were TWO EGA displays).

(BTW, some "video locked" computers as the PC200 had some free ISA slots so they could get any other video card... in PC1512 and 1640 you'll need a external PSU because it was inside the display, but is possible)

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JohnElliott
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Re: [BUG]Amstrad PC1640 Video

Post by JohnElliott » Sat 24 Feb, 2018 11:32 am

Zup wrote:
Fri 23 Feb, 2018 7:42 am
In this page, John Elliot shows different values for dip switches on PC1640 mainboard (funny, it seems that there were TWO EGA displays).
I think you've misread it -- the 'Secondary EGA' settings mean that the built-in EGA remains active, but a CGA or MDA card in an expansion slot is used as the primary display.

There is, I think, a problem with the setup screen in that when the computer has a built-in video card, the settings shown are always for a CGA even if the built-in card is something else.

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SarahWalker
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Re: [BUG]Amstrad PC1640 Video

Post by SarahWalker » Sat 24 Feb, 2018 6:31 pm

Rev 1074 makes it slightly more obvious when a machine with built-in video is selected.

Zup
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Re: [BUG]Amstrad PC1640 Video

Post by Zup » Sat 24 Feb, 2018 10:03 pm

JohnElliott wrote:
Sat 24 Feb, 2018 11:32 am
I think you've misread it -- the 'Secondary EGA' settings mean that the built-in EGA remains active, but a CGA or MDA card in an expansion slot is used as the primary display.
Sorry, I was referring to the fact that second and third line of settings imply that Amstrad could set up the computer with two different models of EGA monitors, one with 200 lines and another with 350. Maybe there were two kinds of EGA monitor for this computer, or maybe they thought about it but scrapped the idea...but the DIP switches allowed that.

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JohnElliott
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Re: [BUG]Amstrad PC1640 Video

Post by JohnElliott » Sun 25 Feb, 2018 2:17 pm

As far as I can tell from the manual, that feature's for compatibility with awkward programs rather than a particular monitor.

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