Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-10, 21:19

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

Two steps forward, two steps back. There is certainly +5V and -12V elsewhere on the card, I can measure them on Pin 4 and Pin 11 of U11, for example. However, there is still no +5V on Pin 14 of U12. There is +5V on the +5V side of R38, but the side that is connected to Pin14 shows no voltage, it is …

---

Re: Bought these games today

Posted on 2020-07-10, 07:31

by

by appiah4

in Milliways

in Milliways

And the Microsoft rampage continues 😀

---

Re: Open source "Dallas" RTC replacement

Posted on 2020-07-10, 07:30

by

by appiah4

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've looked into sourcing parts and building these myself as well but the DS12885 does not seem to be a cheap acquisition in the required SOIC packge type..

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-10, 07:18

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

OK, ZD2 is installed. When I was shopping for a 500mW diode, the seller gave me some that looked suspiciously large, so I bought some 250mW ones as well. I came home and checked the markings vs datasheets online and the alleger 500mW ones were 1W, and the alleged 250mW ones were actually 500mW. It …

---

Re: TXPro Chipset Drivers?

Posted on 2020-07-09, 15:25

by

by appiah4

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The ZIDA 5STX in my daily retro rig is apparently giving up the ghost as it has started having all kinds of stability issues and Memtest86+ results in errors with all kinds of DIMM and SIMM sticks I've tested with it. Possibly needs a recap. Regardless, I am replacing it with a PCChips MB560TG with …

---

Re: Bought these (retro) hardware today

Posted on 2020-07-09, 12:54

by

by appiah4

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hups...I agreed on an acceptable price for 3 boxes with more than 30 kg in total... :-/ There was at least one interesting card in each, therefore I will take only some few items and sell the remaining parts again asap. 1 sellers pic of each box... Boxes arrived, 1st one processed. What I am going …

---

TXPro Chipset Drivers?

Posted on 2020-07-09, 12:15

by

by appiah4

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The ZIDA 5STX in my daily retro rig is apparently giving up the ghost as it has started having all kinds of stability issues and Memtest86+ results in errors with all kinds of DIMM and SIMM sticks I've tested with it. Possibly needs a recap. Regardless, I am replacing it with a PCChips MB560TG with …

---

Re: VLB Multi I/O (UMC) won't work with CF-IDE

Posted on 2020-07-08, 22:05

by

by appiah4

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I did not, I eventually settled for an ISA IO Controller for that DX-33 build. By the way, that DX33 with the missing A27 pin turned out to be a fluke regardless.

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 17:59

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

Looks good. I'd also check the DAC (when removed) in continuity mode. Pins 3, 13, 14 and 15 are in question and should not buzz against pin 2 (GND) and between each other in both ways (switching probes). I checked out of circuit and there is no short between any of the pins 2/3/13/14/15 both ways.

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 16:03

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

Remove SnarkBarker from the machine and check PC's power rails first. On white 4-pin Molex connector black wires are GND, red is +5 and yellow is +12. Google your motherboard and find where you can measure -12V as it is absent on Molex. When, after you install new ZD2, install SnarkBarker and check …

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 15:41

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

Vref- = 0V is good as it is GND. Firstly you should check the power rails of your machine with SnarkBarker removed. You need +12, -12 and +5 rails. -5 is not used. If they look good - remove the DAC (U12) from SnarkBarker, install the card and measure all local supply points, i.e. outputs of ZD1- …

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 15:12

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

Question is why did the diode fail. Was it broken? Did it get destroyed by some overvoltage? I have no clue how the 5V gets created, but a shorted diode is definitely one part of the whole problem. But are there more problems lurking...? ZD2 is on a very simple circuit and it's connected to some …

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 14:35

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

Measure ZD2 out of circuit, e.g. by desoldering one leg. Might be that it failed short. Cap failing is also possible, but more unlikely I would say I checked Pin 11 of U11 and there is no -5V there, so the -5V circuit has failed indeed. Which is strange because I am 100% certain there was -5V there …

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 13:56

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

Try using the diode mode of your meter on the powered off card. It should show the forward voltage of the diode, something between 0.3 and 0.7V. Not sure where Zeners are, but I guess 0.7V. EDIT: https://www.fluke.com/en-us/learn/best-practices/test-tools-basics/digital-multimeters/how-to-test- …

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 13:29

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

I'd measure reference voltage on pin 14 of U12 (DAC). If it is not 5V then the clipping may occur. If it is not - check R38 and voltage drop circuit ZD1, C46-C48, R21. And make sure R22 and R25 are 27k. LABS, You may be onto something! I have absolutely 0V on Pin 14 and Pin 15 (Vref+ and Vref-)! …

---

Re: Bought these (retro) hardware today

Posted on 2020-07-08, 12:24

by

by appiah4

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

MKT_Gundam wrote on 2020-07-08, 12:05: Bancho wrote on 2020-07-08, 10:41: Sound Card/Wavetable Board arrived today. From reading i think this card come out of an IBM machine. S-16FP/L Crystal CS4236 Sound card & S-W1/C Daughterboard with Crystal CS9233 Synth. IS the CS4236 the "broken" Crystal card …

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 12:10

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

I'd measure reference voltage on pin 14 of U12 (DAC). If it is not 5V then the clipping may occur. If it is not - check R38 and voltage drop circuit ZD1, C46-C48, R21. And make sure R22 and R25 are 27k. LABS, You may be onto something! I have absolutely 0V on Pin 14 and Pin 15 (Vref+ and Vref-)! …

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 10:14

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

If you leave the LM393s like that you will have a bunch of baby op amps very soon... same goes for the 74LS74 and a bunch of others... Maybe I should leave them like this overnight? Might be profitable business! I am sad to report that after replacing each and every one of these ICs, the distortion …

---

Re: Tube Time: Announcing The Snark Barker, a 100% Compatible SB 1.0 Replica!

Posted on 2020-07-08, 09:12

by

by appiah4

in Marvin \ Sound

in Marvin \ Sound

Parts are in, more bug hunting tonight 😀

---

Re: What retro activity did you get up to today?

Posted on 2020-07-08, 07:34

by

by appiah4

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Replayed Dune II a lot, thanks to Dune Dynasty. With modern controls, this game is amazing again. However, I still don't know how I got the patience back in the day (on the Amiga, with floppy disks) to win with the Atreides. By the time I had won the final mission, its duration was off the charts …

---