Re: Looking for BIOS for PAT48PG rev 0.30
Posted on 2023-09-21, 08:17
I do own the board in question. I´m unsure about its revision. I upgraded the board with a MrBIOS and it works well. I can dump the original bios if needed.
Re: C64 262 horseshoe connector - making your own for an 1802
Posted on 2023-07-21, 07:24
Have a look at https://www.c64-wiki.com/wiki/A/V_Jack
Re: adding activity LED to an internal ST-225 drive
Posted on 2023-07-01, 16:39
The drive itself has an LED on the front side. I could grab the signal there, but the LED would be dim I think, as the original LED is lit too. I dont want to take the drive apart to remove the original LED. The controller (WD1002A-WX1) has no LED header as far as I know. It has an DC power …
adding activity LED to an internal ST-225 drive
Posted on 2023-07-01, 15:07
I got myself an Turbo XT clone system. Other that it is (was) dusty and grubby it seems to work. I cleaned it thoroughly and am now in the process of reassembly. The no name MFM controller card does not have an header for the HDD activity LED. The ST-225 drive is mounted in a way that it does not …
Re: Reviving PAT48SA mainboard
Posted on 2023-05-29, 16:51
I've replaced the temporary bodge wire with a more robust resistor lead. Not the prettiest one, but this should do the trick. I normally do board level repairs on 8 bit equipment. This is my first one on more modern stuff. I'll cover it with solder mask after dealing with the passives. They are the …
Re: Reviving PAT48SA mainboard
Posted on 2023-05-29, 14:47
Success. I started checking the underside of the board for broken traces. i found a single one, which was affected by the battery leakage. Just this single one. It connects from the 74LS245 right before the first ISA slot to a via and then on the top side to the ISA slots. I temporary bodged it and …
Re: Reviving PAT48SA mainboard
Posted on 2023-05-29, 10:39
Yes, I'm on the hunt for it. The card I use is working fine in another board.
Re: Reviving PAT48SA mainboard
Posted on 2023-05-29, 08:57
Unfortunately I dont have another ISA VGA card to rule out any possible incompatibilities. I'll start toning out traces around the ISA bus at first.
Re: Reviving PAT48SA mainboard
Posted on 2023-05-28, 14:52
4 one megabyte sticks. The RAM is known good one.
Re: Reviving PAT48SA mainboard
Posted on 2023-05-28, 08:49
Thanks alot. I removed all the cache chips and the resistor network. Unfortunately the error persists. While I replaced the blown tantalum I removed the power connector. The trace across the battery place is fine and connects through an resistor and an diode to an 74LS00 chip right under the BIOS …
Re: Reviving PAT48SA mainboard
Posted on 2023-05-28, 07:27
There is a resistor network block, where you can set between 64k and 256k cache. I'm under the impression that removing the resistor network at all disables the cache.
Re: Reviving PAT48SA mainboard
Posted on 2023-05-28, 06:06
Let me bring up this topic again. The board landed on my todo stack and slowly worked up on top again. I've since replaced the blew up tantal with an 10uf/35V one. No change. The board does contrary to my former believe one long beep and eight short beeps. This should be a video related problem. The …
Re: Reviving PAT48SA mainboard
Posted on 2022-02-27, 18:42
Yes, VLB boards are a little cheaper to get these days. But when it comes to VLB addon cards you are in trouble. VLB I/O cards and graphics cards are not that easy to aquire.
Re: Reviving PAT48SA mainboard
Posted on 2022-02-27, 08:09
I started working on this board again and I can now report that the board at least starts POSTing. The post card shows that the board stops at the error codes 40 7b. Unfortunately the screen keeps being black/no signal. The board beeps (if I count correctly) one times long and nine times short. The …
Reviving PAT48SA mainboard
Posted on 2022-02-21, 16:57
It seems I do not have any luck in getting an working 486-era mainboard. I got an PAT48SA-1.30, which is an ISA-only 486 DX50 board, but it looks like it is dead. :-( I snipped the Varta battery as it was in the beginning of leaking. The leakage was only minor and most of the acid went into the …
Re: MS-4145 worth a try?
Posted on 2021-12-25, 17:37
I'll take out the connectors. Someone else dealing with this board was on the same route as one SIMM slot and one COM port is already desoldered.
Re: MS-4145 worth a try?
Posted on 2021-12-25, 17:01
Thanks for your words of encouragement. I`ll follow traces and tone it out as good I can, but I fear I will not have enough diagnostics skills to tackle this board. I even thought about contacting Necroware, as he is -like me- from Germany to the best of my knowledge. Maybe he's interested to make a …
MS-4145 worth a try?
Posted on 2021-12-25, 10:02
In a stash of old computer equipment I found a MS-4145 mobo with serious battery damage. I always looked for a 486 PCI board as I had back in the 90ies. I cleaned the board as good as I could and tried powering up. But it is dead as a doornail. To be fair, it has the most extensive battery damage I …
Re: Just added a IBM NetVista 8303-NUE to my computer collection...What does the NUE mean?
Posted on 2021-03-25, 07:15
With a little bit of luck you can check the original configuration of your machine at https://psref.lenovo.com/WithdrawnBook. IBM and Lenovo were very strict in documenting every possible configuration in their Product Specification Reference.
larger Harddisk for ancient IBM PS/2 56SX
Posted on 2021-03-12, 16:17
I got hold of an IBM DPES-31080 1GB SCSI disk which I would put into my IBM PS/2 56SX to have more space available. Originally it has an 250MB drive in it which works fine. After replacing the drive I got the expected I9990303 error which means the computer could not find its service/system …
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