Re: Bought these (retro) hardware today

Posted on 2021-03-10, 10:25

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There are actually jumpers incl. many undocumented if you look closely :) https://arvutimuuseum.ee/th99/m/A-B/32220.htm 486 boards with Intel chipsets are quite streamlined. They focus on processors with P24D-like pinout. So they don't need to alternate WB cache pins, altenative SL implementations, …

---

Re: Bought these (retro) hardware today

Posted on 2021-03-09, 19:37

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Won the later version for just over a tenner shipped. New collecting goal is to get the full Mach8 to Mach64 reference card set. And sort my collection to see which I already have :) Nice. I have personal attachment to the WinCharger model as it was the card I used in my Pentium PC back in 1996. I …

---

Re: Reviving a bricked Adaptec 1542CP (BIOS flash issue)

Posted on 2021-03-09, 19:35

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Got it working (with 512kBit EEPROMS and duplicated contents) thanks! Lesson learned. At least I am glad I saved the original ROMs. Anyway, if anyone has a BIOS version newer than 1.02 (that supports 4GB disks, please share it)

---

Re: Reviving a bricked Adaptec 1542CP (BIOS flash issue)

Posted on 2021-03-09, 16:09

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Oh. Silly me! I had no idea these can be progammed only once. I was assuming these are ordinary EEPROMs. What is the best way how to pad the ROM to fit larger chip? Just concatenate 32768 empty bytes to the end of the file? Like this? dd if=/dev/zero of=zerobytes.rom count=32768 bs=1 cat zerobytes. …

---

Reviving a bricked Adaptec 1542CP (BIOS flash issue)

Posted on 2021-03-09, 11:29

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I attempted to upgrade BIOS and microcode on my Adaptec 1542CP and it did not end well. I attempted to flash this one to this card: DSC_9387.jpeg I was too lazy to reach for new chips and attempted to update original EEPROM chips :( That was a stupid decision I know. The new update did not work so I …

---

Re: 486 SX 16 & 20 MHz

Posted on 2021-03-08, 21:12

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Going from ISA to VLB should reduce the IO latency on each IO call from 375ns to ~30ns, and should reduce the number of total IO calls by 50% because it is 32 bit wide instead of 16. While what you quoted is true the IO latency expressed in nanoseconds is just a different representation of the bus …

---

Re: Bought these (retro) hardware today

Posted on 2021-03-08, 19:40

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Bought an uncommon new old stock Socket 5 board with UMC chipset. Tandy / Pine / US Logic PT-730A

---

Re: 486 SX 16 & 20 MHz

Posted on 2021-03-08, 16:41

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What video card and storage did you use? Can you do a comparison of ISA vs VLB from 386 to faster 486s? I was always curious to see evidence of a clear MHz inflection point where VLB really starts to become important rather than the 486-66dx2 rule of thumb. Anyway you can quantify the % performance …

---

Re: 486 SX 16 & 20 MHz

Posted on 2021-03-08, 16:12

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

weedeewee wrote on 2021-03-08, 16:04: mpe wrote on 2021-03-08, 14:03: ...and the 486SX-16 is more or less equal to 486SX-16. Any comments are welcome. Just imagine a world where it isn't ... 😉 Edited. Thanks!

---

Re: 486 SX 16 & 20 MHz

Posted on 2021-03-08, 14:03

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hope you don't mind me reviving this thread. I finally got myself to comparing the 486SX-16 against 386DX-40 (where everything else is equal). Something I wanted to settle for a very long time (at least since 1992 when I started wondering about the same :). https://dependency-injection.com/wp- …

---

Re: Diamond Stealth se - ram upgrade won't work?

Posted on 2021-03-03, 22:22

by

by mpe

in Marvin \ Video

in Marvin \ Video

S3 Virge cards almost exclusively used EDO chips which might not work together with FPM you already have on your Trio 32 VLB.

---

Re: Motherboard BIOS Flash?

Posted on 2021-02-28, 11:51

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

For flashing nothing beats tl866ii That's being said. I think ROM don't get easily corrupted on their own (unless you happen to screw up BIOS flashing or something like that). It i just one of many things that can be wrong and unless you have some clear indication that it is the BIOS that's wrong …

---

Re: The good old and glorious 486 DX 50 - and - rant against 25 MHz buses in the Pentium era

Posted on 2021-02-27, 08:28

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

W.x. wrote on 2021-02-27, 06:02: Hey. Anyone knows, how performs DX4-75 (25x3) 16KB in comparsion to DX2/66 8KB? Will it be faster, slower, or about the same? Its is sightly faster (about 10-15%) as the cache and clock easily compensates the lower bus speed.

---

Re: What is the pins for BF0 and BF1 for pentium socket 5?

Posted on 2021-02-27, 07:57

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

BF0 and BF1 signals are simply sampled by the CPU at reset which sets the multiplier Screenshot 2021-02-27 at 07.53.44.png Please note that "0" in the above table means having low signal which typically means having a respective motherboard jumper closed as jumpers often shorten the pin signal to …

---

Re: Intel Over Drive Questions.

Posted on 2021-02-26, 13:49

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes. Those have a fixed multiplier so it likely runs at 166 (f you configure your board to 66 MHz bus) irrespectively what the BIOS says.

---

Re: Bought these (retro) hardware today

Posted on 2021-02-26, 13:22

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Two pickups Sound Blaster CT1920 WaveTable upgrade. Never had one of those so only now I realised it doesn't have any audio jack, just a proprietary header. Need to find out how to connect it. https://dependency-injection.com/wp-content/uploads/2021/02/DSC_9299-scaled.jpeg Also Stealth32 VLB without …

---

Re: Bought these (retro) hardware today

Posted on 2021-02-24, 15:48

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The Stealth64 VLB is a great find! Congrats!

---

Re: Diamond Stealth se - ram upgrade won't work?

Posted on 2021-02-24, 12:20

by

by mpe

in Marvin \ Video

in Marvin \ Video

The RP1 seems to be a pull-up resistor array on memory address bus outputs. I couldn't find a SE with RP1 installed. Two of my Stealth SE PCI cards also doesn't have this RP1 installed and they work fine with 2MB. My Stealth 64 VLB has them but PCI versions don't. I guess it is optional. I'd try a …

---

Re: Pentium on a 386 motherboard ( sort of)

Posted on 2021-02-22, 18:57

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The manual says either single 32x8k or two 8x8k when using 256k. But will try to use two chips. Write-back cache L2 is enabled (confirmed). The fastest timing I could use is 3-2-2-2. Surprisingly, disabling L2 cache delivers almost double memory throughput which is likely better for application …

---

Re: Pentium on a 386 motherboard ( sort of)

Posted on 2021-02-22, 09:28

by

by mpe

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

pshipkov wrote on 2021-02-21, 16:50: _ Thanks. Your AMI BIOS works fine. Haven't noticed any stability/performance difference compared to Mr. BIOS but it is good to have the version that is original for the motherboard.

---