Re: 80286 Adventures

Posted on 2019-03-10, 05:32

by

by retardware

in Marvin \ System Specs

in Marvin \ System Specs

yes, take care to not put the cables the wrong way around! There is almost always a pin 1 mark, make sure that cables are right around both ends. MFM and RLL drives are the same, just the encoding/data rate is ~50% more effective, resulting in higher data density, and smaller bits that decay quicker …

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Build Log: My DOS/Win98 playstation in old IBM 5170 shell

Posted on 2019-03-10, 03:53

by

by retardware

in Marvin \ System Specs

in Marvin \ System Specs

I am going to share the build, because it requires a bit of unusual tinkering. Build aim: To play DOS up to late Win95/98 games with maximum atmosphere and enjoyment factor on an upgraded 1985 IBM PC AT, using a flicker-free high-quality CRT monitor, M keyboard and first-generation MS mouse. Build …

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Re: What retro hardware you killed today or in the past :(. Stories from autopsy room.. RIP= rest in pieces..

Posted on 2019-03-09, 20:16

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

...the colors were messed up lol In the early 1980s I had found a early Goldstar color TV. It had such a shitty tube, so I didn't bother to repair and sell it (I did that for making $$ when at school), instead made an experiment: dropping it hard, turning it on, and looking how the picture changed …

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Re: Need advice: Is this 486 mobo good for a crazy freeclocker project?

Posted on 2019-03-09, 18:25

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

$4 Si5351A dev board https://www.ebay.com/itm/Si5351A-I2C-25MHZ-Clock-Generator-Breakout-Board-8KHz-to-160MHz-for-Arduino-B6R4/173636246022 Great! Looks very sweet! I think this could be what I need! Thank you very much! For the rest I tend to using parts already present here, old arduino with …

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Re: Any way to remove the blue circle mouse cursor from overlaying older games?

Posted on 2019-03-09, 16:01

by

by retardware

in Windows

in Windows

maybe call HideCursor() or equivalent.

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Re: Is there a way to change the internal multiplier of 486DX/n processors?

Posted on 2019-03-09, 15:56

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thank you all for these helpful replies! I will have to let all that information settle to decide which approach I try first. The idea is to implement some kind of "gear" for adjusting the speed of a retro game rig for games from PC 4.77 to end-486 . So it looks possible to implement a 4-speed-gear …

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Re: Need advice: Is this 486 mobo good for a crazy freeclocker project?

Posted on 2019-03-09, 15:37

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

On paper, it goes down to 2MHz, in reality I could boot it at 8MHz but even at that relatively high frequency it just forgot how to write on a PATA device. So the built-in I/O gave up there. Very interesting! Exactly this kind of problems I am expecting. I guess I'll have to experiment which …

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Re: Mouse jumps around screen with HDD activity

Posted on 2019-03-09, 15:13

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

... that was severely bottlenecking. Sorry for OT again, but exactly this is the reason why in my current retro project (upgrading my IBM 5170) I am going to use PCI sound cards. Long ago I read a report in the German "c't" which analyzed the ISA soundcards' impact on computer performance and found …

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Re: Mouse jumps around screen with HDD activity

Posted on 2019-03-09, 05:23

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Borderline power supply which got so borderline that now the HDD load spikes manifest as problems in other locations?

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Re: Showing Off CRT Monitor I Got Today

Posted on 2019-03-09, 02:16

by

by retardware

in Marvin \ Video

in Marvin \ Video

Well I am not nostalgic about getting a 1980s Sony CPD-1402 (my first VGA monitor) back again with its poor 38kHz limit. But what I want is that sharp display in all resolutions, together with the brilliance that only CRT can give. Even the Dell 2007FPb which I initally intended to use for retro …

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Re: Chipset chipped

Posted on 2019-03-08, 19:49

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Multilayer boards often have ground layers for shielding. I'd make sure that there are no shorts between layers and leads (scalpel and magnifier, drop of oil to make FR4 fiber transparent). Sometimes it still works even though it looks bad. But when testing, test only with the most necessary stuff …

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Re: Bought these (retro) hardware today

Posted on 2019-03-08, 19:20

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Bought some parts for my planned low end real mode gaming PC build: https://i.ebayimg.com/images/g/5dIAAOSwe9VcVvSQ/s-l1600.jpg cacheless 486 mobo with hardware UMB and EMS support ( for technical details see this thread ) a lot with containing a few possibly useful cards, a few of them: https://i. …

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Re: 775 to 771 mod - BIOS microcode issues

Posted on 2019-03-08, 15:58

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There is a bios modding section in this forum, where some very experienced bios modders hang out: https://www.win-raid.com/forum.php Definitely worth reading! Regarding microcodes, you might find what you are looking for here: https://github.com/platomav/CPUMicrocodes

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Re: DOS Video Issue @ 700x400 via VGA

Posted on 2019-03-08, 05:32

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

At one point, after running SJGPlay for a while, after the screen lost some pixels, I wiggled the analog audio cable that connects from my Yamaha MU80 into my audio splitter (which then connects to the header on my Sound Blaster Live 5.1 card). This temporarily fixed the problem. [...] I'm not sure …

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Need advice: Is this 486 mobo good for a crazy freeclocker project?

Posted on 2019-03-08, 04:36

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hello, I have a crazy idea and need your advice. My idea is making a pure-real-mode freely-clockable DOS PC that can run very old software from Zaxxon (for 8088 PC) up to software that works fine up to 486s. (Ideally in the end finely adjustable by a steampunk potentiometer and an giant analog …

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Re: Can anybody identify that TMS34020 Number Nine card?

Posted on 2019-03-08, 02:44

by

by retardware

in Marvin \ Video

in Marvin \ Video

Thank you again @Elianda! I just did some testing, and found the reason for which was wrong. https://i.postimg.cc/TYVt15T6/DSCN9353.jpg When displayed in 1152x870x24, it looks like shown above. Distorted and with a white bar in the middle right section. The card for some reason seems to support only …

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Is there a way to change the internal multiplier of 486DX/n processors?

Posted on 2019-03-08, 00:25

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What I would like to do is to change with, say a 486DX/4-133, between, say, 1x, 2x, 3x and 4x. So the processor works with 33MHz (respective bus frequency), 66, 100 and 133, respective. Is this possible? if it is possible, does it work the same way on all 486 or only on particular types/brands?

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Re: ATX I/O shield models for 3D printing

Posted on 2019-03-07, 23:43

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just found out which single shield layout probably will "sell" best: with just one DIN connector, nothing else... ...just for putting an AT mobo into an ATX case! Maybe there might be an additional variation with some holes for DB9 (COMx), DB25 (COM/LPT), mini-DIN (PS/2mouse), for which on many …

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Recommendable DOS network cards/chipsets for ISA bus?

Posted on 2019-03-07, 23:04

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Which network cards would you recommend? I could need one for using another Windows machine or a Samba server for storage. You know, MS Lanman and all that almost forgotten stuff. Priorities: 1. Ideally the card supports 100Mbit. 2. It must have a modern RJ patchcable connector. 3. The card is known …

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Re: 50-pin SCSI controller advice ?

Posted on 2019-03-07, 22:43

by

by retardware

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Nowadays because of the driver support there is no real no-pain alternative to the 1542 🙁 If you have a separate diskette controller, a 1540 does, too.

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