Re: CRT “crack” sound + picture flicker

Posted on 2018-06-21, 20:02

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That's moisture in the neck connector and the moisture causes focus and acceleration voltages to arc every once in a while. Thoroughly dry out the connector (with a hair dryer or something). Also pay close attention to area around the flyback transformer, any discharge there can result in …

---

Re: RAM with TIN vs GOLD connectors compatibility

Posted on 2018-06-21, 15:22

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There are application notes from various connector manufacturers about tin and gold plated connectors mating and all of them say this is something that shouldn't be done as it degrades the gold plated connector.

---

Re: RAM with TIN vs GOLD connectors compatibility

Posted on 2018-06-21, 15:02

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

You can tin the contacts but you'll have to make sure there's no excess tin so as not to damage sockets. Use solder wick to get rid of any excess or even as a method to plate the pins. Apply flux, drag the wick with some solder over the pins while holding iron on it. Should work very well and be …

---

Re: The best 4:3 monitor?

Posted on 2018-06-20, 21:34

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It should be noted that 1280x1024 monitors are 5:4 and not 4:3. 1280x960 monitor would be 4:3 but those seem to be rare, like 1600x1200, 1920x1440 and 2048x1536 are. The few I have seen always go for a lot of money...

---

Re: Reading unmapped I/O ports on old PC hardware

Posted on 2018-06-20, 21:17

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

When ISA is also the FSB as it is case with stuff older than 386 you get last fetched instruction or data read/write on the bus held by capacitance when there are no pull up or pull down resistors on the bus.

---

Re: The best 4:3 monitor?

Posted on 2018-06-20, 17:25

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you take a photo in ambient light things aren't gonna look all that favorable, reflections and the light itself making phosphors glow (try turning light on and off for a second in a dark room and then look at the screen, you'll see a faint glow for a little bit). It doesn't help when the …

---

Re: ISA Graphics Card Dead, any chance of resurrection?

Posted on 2018-06-19, 19:22

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The pictures definitely suggest the fault being in some data line(s) of VRAM bus. Straight vertical lines at regular spacings. Address issue would manifest in repeating graphics. MCU wouldn't make a very good video card, there's no CPU time to handle both data writes and displaying the image. FPGA …

---

Re: ISA Graphics Card Dead, any chance of resurrection?

Posted on 2018-06-19, 13:56

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That kind of looks like bad a DRAM chip, since the machine boots and you get things happen the ROMs and ISA side of things works. What happens when you run some VGA game ?

---

Re: Tseng 4000AX Weird Characters

Posted on 2018-06-19, 13:51

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

You definitely cannot program an EPROM directly on the GFX card and none I have seen even has !WE signal so a flash chip wouldn't be upgradeable either (that came along well into the PCI era). 200ns might be too slow too, if you experience weird things with the new chip you'll want to get 150 or …

---

Re: Tseng 4000AX Weird Characters

Posted on 2018-06-14, 21:59

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

This makes me think of a localized charset for some specific purpose. Are you sure there's no charsets being loaded in config.sys or autoexec.bat ?

---

Re: Burning BIOS to a new EEPROM

Posted on 2018-06-14, 15:48

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The intel chip uses 12V programming voltage while the other part is 5V only

---

Re: Burning BIOS to a new EEPROM

Posted on 2018-06-14, 14:07

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Latchup is a real thing (and can and will happen if ground isn't gonnected) and also IO pins will become power pins through the ESD protection diodes putting unnecessarily high current requirements on the IO drivers of the motherboards during that time if VCC isn't getting connected. Reverse …

---

Re: Burning BIOS to a new EEPROM

Posted on 2018-06-13, 20:28

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Suppose you buy one of those epromm flashers from ebay that come with a kit full of tools and things. and over the years you were able to remove more than 10 bios chips from broken motherboards that were trashed. is it easy to flash those chips? you just remove the sticker, place them under a UV …

---

Re: Burning BIOS to a new EEPROM

Posted on 2018-06-13, 18:46

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That is called hotflashing and it is possible but care must be taken to make sure pins contact roughly at the same time. Stuff like pushing in one side and then other is a big no-no and can result in destruction of the chip and in worst case damage the motherboard too.

---

Re: Sound Blaster 2.0 project & IRQ from OPL2

Posted on 2018-06-10, 12:24

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

Real Adlib actually has IRQ almost ready for use, it just lacks the pin header (from factory) that actually connects IRQ output to ISA (though a buffer). I'm not aware of any sound card connecting the YM IRQ to ISA except YMF711/715/718/719 cards if the software configures the chip right.

---

Re: Wrong Color in DOS

Posted on 2018-06-06, 18:08

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Red color in the VGA cable/connector/monitor isn't working if all else is discolored too. Replacement of the cable can be done although it isn't very easy. Fixing a cable is near impossible. Try wiggling it at the point where it connectso to computer and to the monitor. I have seen many monitors …

---

Re: Would any modern-day fan/power supply work on 90s PC?

Posted on 2018-06-06, 09:03

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Voltage divider from -12V to -5V will fool the sensor in that case.

---

Re: ESS AudioDrive ES688F, weak/screatching sound

Posted on 2018-06-05, 16:09

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

Photo of back of card will reveal everything. Most stuff I see uses +/-12V, +/-5V is pretty uncommon.

---

Re: In Awe 64 there are wrong voices in midi music.

Posted on 2018-06-04, 14:31

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

Increase wait states / recovery time on 8bit ISA accesses in the BIOS or if that option doesn't exist then reduce ISA bus speed.

---

Re: CRT monitor Calibration - Anyone here ever did that?

Posted on 2018-06-03, 04:10

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Those are magnets used to improve purity mainly (i.e a pure color is that and tinted with another) but they will have effect on convergence too (alignment of individual colors). You could try move an existing one or add in another, in any case it'll be lot of trial and error with positioning aswell …

---