Search \ VOGONS

Re: Market value for popular or rare classic computer hardware

Posted on 2022-04-13, 13:04

in Milliways

TrashPanda wrote on 2022-04-13, 05:42: And from experience 90% of drives in that class and of that age tend to give up the ghost during POST what an absolute load of BS

Re: Remarked Dallas RTC chips?

Posted on 2022-04-12, 18:05

by maxtherabbit

in Marvin \ General Old Hardware

Filename 20220412_135534.jpg File size 1.23 MiB Views 345 views Filename 20220412_135515.jpg File size 1.42 MiB Views 345 views Filename 20220412_140052.jpg File size 1.23 MiB Views 345 views Definitely a remark job. No way a lithium primary self discharged to 0.9V in 5 years of shelf life without …

Re: Remarked Dallas RTC chips?

Posted on 2022-04-12, 15:41

by maxtherabbit

in Marvin \ General Old Hardware

Same thing happened to me a while back... another thing I noticed was that the legs of the chip were unusually thin, which caused a couple of them to break when I removed it. Not sure if we're talking about the same seller but I won't be buying from that one again. shit now that you mention it it …

Re: Max no. of 16 bit ISA slots in a 386 board

Posted on 2022-04-12, 15:14

by maxtherabbit

in Marvin \ General Old Hardware

some very old 8-bit cards actually extended down below the edge connector behind the 8 bit slot, omitting the 16bit extension was a mechanical backwards compatibility measure

Remarked Dallas RTC chips?

Posted on 2022-04-12, 14:24

by maxtherabbit

in Marvin \ General Old Hardware

About roughly 2 years ago I bought a DS12887+ from ebay. Was from a highly rated seller and sold as NOS. 2017 Production date printed on it. As soon as it arrived, I tested it in a machine and it worked fine. The project I had intended to use it for never materialized, so I stopped the clock as …

Re: VGA cable replacement for PN17J0

Posted on 2022-04-11, 15:22

by maxtherabbit

in Marvin \ General Old Hardware

First of all, based darkplace enthusiast. Secondly, you can either desolder the cable and replace it with another one (using mini coax, please) or you can kludge together a female DE-15 into the monitor case, cut off the existing cable inside amd solder it directly to the back of the jack

Re: PowerVR Fun Thread

Posted on 2022-04-11, 00:55

by maxtherabbit

in Marvin \ Video

Was there anything special about the driver code in the matrox version of the hexen 2 demo? Or was it just the same old SGL wrapper? (Sorry for shitting up the PVR esoteria thread with such a mundane topic)

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-10, 13:26

by maxtherabbit

in Marvin \ General Old Hardware

my best guess is they just couldn't be bothered to implement different bus timing logic for memory and I/O transactions, either due to laziness, cowardice, or both

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-09, 19:52

by maxtherabbit

in Marvin \ General Old Hardware

However the ~2MB/sec figure I was citing earlier can be seen in other benchmarks 20220409_130450.jpg Likely, those benchmarks use 8-bit cycles to address the video card. That will drop performance by a factor of two. I don't think so. (This was with the 24MHz ISA oscillator FYI) 20220127_193709.jpg …

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-09, 17:05

by maxtherabbit

in Marvin \ General Old Hardware

So our quick math is indeed commensurate with what we're getting in landmark Filename 20220409_130248.jpg File size 782.16 KiB Views 599 views However the ~2MB/sec figure I was citing earlier can be seen in other benchmarks Filename 20220409_130450.jpg File size 1.23 MiB Views 599 views

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-09, 16:25

by maxtherabbit

in Marvin \ General Old Hardware

SBHE# is low for the duration of the transfers, so it is doing words not single bytes

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-09, 15:05

by maxtherabbit

in Marvin \ General Old Hardware

So it looks like your writes are 4 clocks apart, whereas ideally with the zerows mode it should be less than that. But at this rate you should still be getting close to 4MB/s? Unless these are only byte writes? around 3.8MB/s yeah hmm....... I'll move the probes over to MEMCS16# and SBHE to make …

Re: Which is the best and most memory efficient CD-driver?

Posted on 2022-04-09, 14:19

by maxtherabbit

in Marvin \ General Old Hardware

I've literally never had a problem with cute mouse been using it for like 10 years almost Are those of you having troubles with it using serial or ps/2?

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-08, 23:05

by maxtherabbit

in Marvin \ General Old Hardware

1) its triggering on the memory strobe 2) who cares 🤣 3) I didnt bother to ground that probe

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-08, 20:30

by maxtherabbit

in Marvin \ General Old Hardware

Here are some more with a 3rd probe on 0WS#

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-08, 20:14

by maxtherabbit

in Marvin \ General Old Hardware

Looking at the width of the memory write strobe (~100ns) we can see that the memory writes to VRAM are working as intended and 0WS# is being properly sampled. Looking at the number of clocks between the strobes we can see many extra cycles, indicating the board applying IO recovery time.

Re: 486 Motherboard with abysmal ISA performance

Posted on 2022-04-08, 19:12

by maxtherabbit

in Marvin \ General Old Hardware

Top trace is MEMW#, bottom trace is ISA clock. Probed while running 3dbench2 on continuous loop

Re: Voodoo 2 banding issues in 640x480 only

Posted on 2022-04-08, 17:00

by maxtherabbit

in Marvin \ Video

yeah that's normal, look for something to low-pass that signal before trying to digitize it I recently got back to this after acquiring two Voodoo 2s for SLI and they exhibit the same issue. (Was kinda hoping the interleaved signal would maybe hide it a bit, but it only doubled the amount of bands …