Re: 8-bit compatible ISA-16 Multi-I/O (and not only)

Posted on 2024-02-06, 00:15

by

by Gustavo

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The main question here is if there any well-known 16-bit Multi-IO card (such as Prime2, or something generic like that), having the similar 8-bit compatibility mode as TVGA cards, or a known method of connecting a standard drive to this 20-pin interface? I know about specific modern cards but I’m …

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Re: Connect CGA card to VGA monitor with better palette (circuit)

Posted on 2024-01-26, 11:29

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

VileR wrote on 2024-01-26, 09:47: Cute - that palette reminds me of the Apple ][, specifically those games that used HGR mode with the high bit always set (e.g. https://www.mobygames.com/game/23779/the-goon … enshots/apple2/): you get black, orange, sky-blue, and white. 😀 Sure! Also the TRS CoCo´s. …

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Re: Connect CGA card to VGA monitor with better palette (circuit)

Posted on 2024-01-25, 23:19

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

I have tried many other arrangements, but one thing that I needed was pure white to be present in the main palette (white, cyan, and magenta originally). Notice that when all three signals are high at the CGA card, the VGA connector gets the same value on R, G, and B, giving a white pixel.

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Re: Connect CGA card to VGA monitor with better palette (circuit)

Posted on 2024-01-24, 22:14

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

A CGA card outputs red, green, blue, and intensity signals in TTL voltage. That means +5 volts when each of these signals is active and 0 volt when it is not. There are 16 possible combinations, and so CGA can only display up to 16 colors. A VGA monitor accepts red, green, and blue signals in " …

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Re: Connect CGA card to VGA monitor with better palette (circuit)

Posted on 2024-01-24, 20:20

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

15 kHz is like a lottery. Some very cheap TFT monitors do accept 15 kHz. This is the one I got: MONITOR TGT ST17G, 17 POL., TN, HD, 3MS, 75HZ, HDMI, TGT-ST17G-BL01

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Re: Connect CGA card to VGA monitor with better palette (circuit)

Posted on 2024-01-24, 14:56

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

https://i.postimg.cc/FfgNc13p/Whats-App-Image-2024-01-24-at-10-55-26.jpg https://i.postimg.cc/rzpM0VmG/Whats-App-Image-2024-01-24-at-10-55-27.jpg https://i.postimg.cc/62WwhwhX/Whats-App-Image-2024-01-24-at-10-55-27-2.jpg https://i.postimg.cc/KKFyZFwM/Whats-App-Image-2024-01-24-at-10-55-28.jpg …

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Connect CGA card to VGA monitor with better palette (circuit)

Posted on 2024-01-24, 14:53

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

Hi Everyone! We all know how the CGA palette has been criticized. Recently, I acquired a 15-Khz-capable VGA monitor, and have been experimenting with various ideas to connect a CGA card to it. Eventually, this is the circuit I have come to: https://i.postimg.cc/Vs90nJJg/circuitopaleta.png It has …

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Re: Games that run on 8088 4.77mhz that take advantage of a VGA Card

Posted on 2024-01-05, 12:52

by

by Gustavo

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Pinball Fantasies will run fine on a 10Mhz XT with NEC V20 (It needs 286 instructions) and sound disabled. The CPU can´t keep up with the MOD player used in the game. I think it could be playable on a 4.77 XT with V20 processor. Another World (Out of this Wolrd) runs perfectly on that machine …

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Re: Possible to output 320x200 for EGA games? (re: doublescanned 640x400)

Posted on 2022-10-19, 01:50

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

I’m going to try some of the utilities mentioned but I’m confused how any of the tools can force 15 kHz when it sounds like everybody is saying VGA is always line doubled? It intercepts the BIOS calls and uses a modified video mode. I´ll post the README from the second utility: --- The program …

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Re: 15 FPS Doom 2 with Pentium MMX 200

Posted on 2022-10-18, 14:40

by

by Gustavo

in DOS

in DOS

What is going on. Is this the best a Pentium MMX 200 can do? Is my memory from '94 rose tinted? Try increasing the ISA bus frequency in the BIOS SETUP (that is decreasing the clock divider). You may also try other FSB/CPU clock combinations, as to increase the ISA bus frequency, even if it slows …

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Re: ISA sound card for Windows XP

Posted on 2022-10-16, 20:33

by

by Gustavo

in Marvin \ Sound

in Marvin \ Sound

These are the ISA sound cards I have on hand: SoundBlaster CT2290 - true OPL3 card, it's in my K6 system for now SoundBlaster CT4170 Vibra 16XV - fairly integrated card, CQM Aztech 138-MMSN855 - interesting card with a modem, but not sure how good it is Hi! CQM sounds very bad with FM music. I once …

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Re: Possible to output 320x200 for EGA games? (re: doublescanned 640x400)

Posted on 2022-10-16, 01:11

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

Does anybody know if it's possible to output 320x200 (EGA) on a VGA card? If I understand correctly, VGA cards doublescan the output resolution so 320x200 is output as 640x400 (confirmed on my PC monitor and scalers). I'm testing an upscaler (DExx, from the creator of the OSSC) which can upscale to …

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Re: Possible to output 320x200 for EGA games? (re: doublescanned 640x400)

Posted on 2022-10-15, 17:54

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

Grzyb wrote on 2022-10-15, 13:01: What VGA card you have in that Turbo XT? Chances are, it supports register-level CGA compatibility mode... Trident T8900D or 9000B, don´t remember now. But the utility I mentioned sets the VGA card to 480 line mode to obtain a 60Hz refresh. That´s the reason …

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Re: Possible to output 320x200 for EGA games? (re: doublescanned 640x400)

Posted on 2022-10-15, 11:50

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

https://github.com/joncampbell123/doslib/blob … hw/vga/vga240.c This utility can set some VGA modes to 60Hz. Tried with AlleyCat and it indeed set it to 60Hz (the image gets a little squashed). It did not solve the delay problem I mentioned.

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Re: Possible to output 320x200 for EGA games? (re: doublescanned 640x400)

Posted on 2022-10-15, 10:29

by

by Gustavo

in Marvin \ Video

in Marvin \ Video

maxtherabbit wrote on 2022-10-15, 02:42: CGA/EGA games do indeed sometimes run too fast at 70Hz Alley Cat has some small delay in the controls with VGA card on a Turbo XT. The problem of course don´t occur with a CGA card. Could it be the 70Hz refresh?

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Re: FLAC2WAV and WAV2FLAC [8088][286]

Posted on 2022-10-11, 09:35

by

by Gustavo

in Release Announcements

in Release Announcements

I'm wondering how long it takes to decode 1 minute of FLAC sound on an 8088@4.77... ...but no, I don't want spoilers, some day I'm going to revamp my Turbo XT, set it to de-turbo, and see for myself XD I´m curious too. I bet it will be more than an hour, but sometimes the little Intel surprises me.

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Re: Commander Keen 4 graphical glitches on Windows 95/98

Posted on 2022-10-11, 09:26

by

by Gustavo

in Windows

in Windows

Try changing these settings:

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Re: Joystick woes and questions

Posted on 2022-10-08, 10:14

by

by Gustavo

in Marvin \ Software

in Marvin \ Software

Jo22 wrote on 2022-10-08, 05:02: It could read natural information of our real world, like a reading from a temperatur sensitive resistor (NTC/PTC) or a light sensitive resistor (LDR). Yay! Hey!! I did that in the late 80´s, with QuickBasic, and plotted a graph or made some weird sound with the …

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Re: Joystick woes and questions

Posted on 2022-10-08, 00:21

by

by Gustavo

in Marvin \ Software

in Marvin \ Software

Flight simulators? Simulation games were much more playable with analogue joysticks. And corporate dudes totally loved simulations. Flight sims, golf sims, .. Yes, I know, but it really ruined the gaming experience for every other genre. The king of (bad) joystick is the TRS Coco with its non auto- …

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Re: Joystick woes and questions

Posted on 2022-10-07, 10:31

by

by Gustavo

in Marvin \ Software

in Marvin \ Software

With many old games (i.e. Montezuma´s revenge), the joystick will only work correctly with a 4.77 MHz machine. Even a Turbo XT (10 MHz) can break joystick support on these games. Why didn´t IBM go with digital joystick, like Atari, Amiga, MSX and almost all 80´s vidogame consoles.

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