Re: PC chips M912 cache
Posted on 2022-01-12, 07:37
Here are some pictures. Andrew
Re: PC chips M912 cache
Posted on 2022-01-12, 05:03
Which version of the M912 is it ? There are two (1.4 and 1.7) and they are slightly different..look by the Keyboard connector it should have a V #. Can you post a good picture of the board ? Apologies, I should have said. Its a V1.7 board. I'm at work currently, but will post some photos when home. …
Re: PC chips M912 cache
Posted on 2022-01-11, 23:30
My Moondog whitebox 486 DX4 has one of those M912s with a real Cache on it that works. Typically the way to tell is if the chips are socketed or not, and to see if the cache traces on the motherboard lead to other components, or if they just loop back into themselves. I also have a (dead) Pc Chips …
PC chips M912 cache
Posted on 2022-01-11, 19:56
Hi all Got given a PC Chips M912 a while back, which I'd quite like to use for a 486 DX4 build. However it is one of those boards with the fake cache. Having first checked that all the traces do actually seem to go somewhere, rather than just being for decoration, I desoldered all the chips and …
Re: Unknown BIOS chip and motherboard
Posted on 2021-12-15, 05:43
Sorry, me again. That site you linked is really helpful. I've had another look and I reckon its an M530. Cheers Andrew
Re: Unknown BIOS chip and motherboard
Posted on 2021-12-15, 05:39
Actually, just looking again, I spot a couple of differences? Mine only has two cache chips and then one of the chipset chips next to them, whereas the M535 has both chipset chips towards the middle of the board and 4 cache chips? Could this just be down to different revisions of the board? Andrew
Re: Unknown BIOS chip and motherboard
Posted on 2021-12-15, 05:37
Brilliant, thank you. I was slightly thrown as the diagram of the M535 I found didn't quite match, but a picture of the actual thing is spot on! Now just to sort this pesky BIOS chip! Cheers Andrew
Re: Evergreen 486 SuperChip - settings for DIP switch?
Posted on 2021-12-15, 05:33
Just seen this thread again. I'll try and dig mine out in the next few weeks and take another look. I've been meaning to ever since CPU galaxy did the video on enabling the L1 cache, which I now realise was never enabled on mine. I know mine used to refuse to post at a 16MHz "FSB" but worked fine at …
Unknown BIOS chip and motherboard
Posted on 2021-12-15, 03:50
Hi all Needing a Pentium 166MMX, I managed to find this motherboard complete with the CPU for basically the same price that CPUs only were selling for on ebay. Sold as non working, the keyboard port had been desoldered, but fitting one from a dead board and it was soon working fine. However, I …
Re: 286 motherboard CMOS battery
Posted on 2021-11-25, 04:20
Cheers, sorry, missed your replys I actually have gone with the 3x AA battery solution, on nice long wires at the bottom of the case. I've actually used 1.2v rechargable ones, and left the charging enabled. Seems to work well. Turned it on after a month of sitting the other day, CMOS settings as …
Re: 286 motherboard CMOS battery
Posted on 2021-10-08, 04:06
Well just an update I finally stripped the PC this was fitted to and traced the current path from the battery positive pin. Itt went to 4 places, one of the chipset chips which contains the RTC, a 14 pin IC, a tantalum capacitor and a PNP transistor. I pulled the transistor out and it tested as bad …
286 motherboard CMOS battery
Posted on 2021-04-29, 14:20
Hi all I have a DFI TOP286 motherboard that originally had the dreaded Varta battery on it, which when I bought it had wreaked its havoc. It was my first attempt at repairing a board like this, but it now works fine, except for 1 issue. It has pins and a jumper for an external battery, so after …
Re: Evergreen 486 SuperChip - settings for DIP switch?
Posted on 2021-03-06, 20:54
No rush at all, when you have time to have a think, drop a reply and I'll have a play with it when I get a chance! Skip
Re: Evergreen 486 SuperChip - settings for DIP switch?
Posted on 2021-03-03, 19:32
Could you confirm if the L1 cache is working and ensure that the CPU is running at 25 MHz? This will let us know that the DIP settings have the external 2x multiplier enabled and the L1 enabled. Hi feipoa, Apologies, I made a start on playing around with it, but have been crazy busy recently. I …
Re: BIOS image collection - requests, discussion etc
Posted on 2021-01-31, 02:07
Hi I have a BIOS that doesn't seem to be featured, I have dumped it and am happy to upload it, but I'm just not sure where to put it. Its a motherboard I bought the other day for cheap. It is a DFI TOP-286 board, however, it has an Evergreen 286-486 upgrade fitted and seems to be running a 386 BIOS …
Re: CRT monitor repair
Posted on 2021-01-25, 18:19
Thanks Tiido I think what I need to do is pack it away fir a little while, I have quite a bit on my plate currently ad I'm just starting some construction work. I need to do some research and then invest in a decent oscilloscope. Once I have that, I'll have a proper dig into it. At the moment I'm …
Re: Evergreen 486 SuperChip - settings for DIP switch?
Posted on 2021-01-23, 09:48
Well, I can now confirm that mine works. I have it set up with a fresh install of DOS 6.22, so if theres anything you'd like checking out, please let me know. Skip
CRT monitor repair
Posted on 2021-01-21, 03:04
Hi all I'm hoping to get some pointers from someone who has experience in repairing CRT monitors, as information online seems to be very lacking. I decided starting a new thread was probably best for this, as it is very much a tangent from the thread I posted the other day on the same monitor. …
Re: Evergreen 486 SuperChip - settings for DIP switch?
Posted on 2021-01-19, 03:18
Skip, thank you. It looks like the plot has thickened. The PAL revisions on yours are the same as mine and both of our units have no FPU, however, your DIP switch settings are still different than mine. Yours is 6:off, 4:on. Mine is 6:on, 4:off. All others are the same. From the 4 photo examples …
Re: Gateway 2000/Tatung CM-1495 CRT
Posted on 2021-01-19, 03:02
Thanks Hanamichi. I've checked the cable pinout and its just straight through, so have built myself an adaptor as per your first link. Went to test it and have discovered bigger issues, the monitor is dead! Power LED comes on, tube heater starts glowing, but I'm pretty certain I'm not getting HV as …
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