Re: Serial mouse worked only for a day on DOS machine

Posted on 2022-05-17, 13:43

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In the photo of the board the if I'm counting correctly it looks like it's JP5 set to 2-3, with JP6 set to 1-2? If that settings sheet is correct then JP5 on 2-3 disables the external serial port. [I'm guessing those resistors are pull ups for the game port switches. If you're not using the gameport …

---

Re: Serial mouse worked only for a day on DOS machine

Posted on 2022-05-13, 13:31

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Odd. Do you have access to any other machine to check the mouse is ok? Also, I think I've read somewhere that some mice could change protocol if you hold down the left button when turning the machine on, so maybe try that. Does it help if you pull the sound card out?

---

Re: Epox EP-58MVP3C-M - undocumented 5.5V multi, 112FSB?

Posted on 2022-05-09, 17:01

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

With a decent photo of the area around the J3 selection jumper block then it might be possible to work out if the clock generator has other options that you might be able to make a modification to select. It looks like they might be doing a unary to binary conversion so a single jumper sets the 3 …

---

Re: Searching for 8517 v3.3 Ali M1217 manual

Posted on 2022-05-05, 20:41

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There are 3 very similar looking boards on UltimateRetro: https://www.ultimateretro.net/en/motherboards/6803 https://www.ultimateretro.net/en/motherboards/2497 https://www.ultimateretro.net/en/motherboards/6813 of which the second one (Gemlight) has a MicroHouse sheet with some settings that might …

---

Re: What cpu to use on this olivetti motherboard?

Posted on 2022-05-03, 11:59

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

487SX co-processer? https://www.ardent-tool.com/Olivetti/Docs/ser … tems1/cap36.pdf

---

Re: Microsoft Serial Compatible Mouse only works in PS/2 mode

Posted on 2022-04-28, 09:21

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

On the adapter you got, it looks like the TX/RX/GND match and it's the +/- 12V and reset signals that are different. The colours of your internal 6 pin connector match the one that was in my mouse, and the PCB revision is the same. MS_900334122_PCB.jpg Some of the resistors are different values and …

---

Re: MT-203s Controller Card Manuals/Jumper Settings

Posted on 2022-04-25, 21:06

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If no one else jumps in, then here's a board with a similarish layout, including a bank of 10 jumpers, maybe you'll get lucky: https://arvutimuuseum.ee/th99/c/U-Z/21335.htm

---

Re: Blown and burned Mosfet, can it be repaired?

Posted on 2022-04-20, 16:24

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Drain tab will need to be connected somehow to the top layer of copper. Maybe you could modify a TO220 case style (rather than the TO263 / D2PAK) so you can solder the middle pin to where the tab was and screw a heatsink on. Getting it mechanically supported will be important so that no more damage …

---

Re: Help in identifying and troubleshooting an old motherboard

Posted on 2022-04-20, 15:19

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If someone can help me locate the charging circuit so I can place the diode, I will welcome any help. As Dionb said, looks like header J3 is an external battery connector, with diodes already fitted on the board. 3xAA cells should be ok, probably +ve to pin 1 and -ve to pin 4 (check if pin 4 …

---

Re: Microsoft Serial Compatible Mouse only works in PS/2 mode

Posted on 2022-04-19, 16:58

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I had a go at working out the wiring for a MS 45717 PS/2 mouse, which is also serial port compatible: Re: Microsoft PS/2 to serial pinout? But there's no guarantee that Microsoft used the same pinout for different mice.

---

Re: md-4duv-ver 2.1 Motherboard, Need to track down a Manual

Posted on 2022-04-17, 00:45

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Looks like JP1 pin 1 is +ve, pin 4 is Gnd. 3xAA battery pack (so 4.5V) should do.

---

Re: md-4duv-ver 2.1 Motherboard, Need to track down a Manual

Posted on 2022-04-12, 10:59

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Er, not sure if that's right. Compare pinouts of https://pdf1.alldatasheet.com/datasheet-pdf/view/47637/WINBOND/W24257AK-15.html with https://www.digchip.com/datasheets/parts/datasheet/523/W24512A-pdf.php That's the 28 pin 32KB vs the 32 pin 64KB. To get the pins to line up, pin 1 of the 28 pin …

---

Re: MOSFET testing question

Posted on 2022-04-10, 23:41

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I don't have massive amounts of experience, but it looks like it's FET with a low threshold voltage, datasheet says 1.5V typical, dropping as temperature increases. Perhaps there was some stray capacitance on the gate when it was in-circuit, enough to drop the drain-source resistance. Still sounds …

---

Re: md-4duv-ver 2.1 Motherboard, Need to track down a Manual

Posted on 2022-04-08, 16:57

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Not that I can find, sorry. With a bit of time and a multimeter it should be possible to figure out if any of the jumpers are voltage selects, and what the voltage options are.

---

Re: MS-6156 OEM Motherboard - Opinions on capacitors

Posted on 2022-04-08, 16:54

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

From the photos, looks like Vcore is controlled by an SC1152, datasheet here: https://pdf1.alldatasheet.com/datasheet-pdf/view/42490/SEMTECH/SC1152CS.html That says the lowest it supports is 1.8V, but it also says that any Vid not specifically listed will cause a shutdown. So if the CPU asks for 1. …

---

Re: md-4duv-ver 2.1 Motherboard, Need to track down a Manual

Posted on 2022-04-08, 16:07

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just had a closer look and it turns out there are differences between the DUV and DUVC where they shifted one of the two big jumper blocks by the CPU to make way for the voltage select jumpers. You can make them out in this photo of the DUVC: https://i.ebayimg.com/images/g/KlEAAOSw0R9gRC49/s-l1600. …

---

Re: Help in identifying and troubleshooting an old motherboard

Posted on 2022-04-08, 11:14

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

https://www.ultimateretro.net/en/motherboards/9758 Not all that useful since it's unknown and with no documentation. Could be a chance to fill in some of the gaps if you can get it running and/or get a copy of the BIOS. [edit: RAM might need to be in pairs, so you might need 2 sticks] [edit2: …

---

Re: intel VS440FX (Venus) - Socket 8 motherboard - need help

Posted on 2022-04-07, 08:43

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yeah, you can see the damage and some solder rework on the big inductor L9L1, and half of C9L1 is still on the board, plus there's some other rework been done with surface mount capacitor C8M1 being replaced with a through-hole. Given the amount of damaged components I'm surprised at how little …

---

Re: intel VS440FX (Venus) - Socket 8 motherboard - need help

Posted on 2022-04-06, 22:29

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I think the +ve marking is maybe for the diode CR9K1? As you say, I don't think ferrite beads have a polarity.

---

Re: intel VS440FX (Venus) - Socket 8 motherboard - need help

Posted on 2022-04-05, 16:03

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Not much help, but from the photo: L8L1 : HM00-94885A This'll be an inductor of some sort, but can't find a datasheet for it, so it'll need to measured or guessed FB8L1 : unmarked as far as I can see, a ferrite bead of some value, but again will need to be measured or guessed C9L1 : ceramic …

---