First post, by manalog
Hi all, I am new to Vogons. I am a 23 years old guy really passionate about retrocomputers, especially the ones of 1990s. I got several of them, but now I’d like to ask you some suggestions about one of those, a Pentium 100 build.
Specs: Highscreen branded, PA-2000 motherboard, Pentium 100, 16 MB 72 pin DIMM, 1GB Quantum hard drive, S3 video card, Windows 95. It is a devilishly fast computer, really, it surprises all of my friends for how much it is fast. Soon (today perhaps) I’ll try to install a Creative CT3990 I found in the garage (was I lucky? Is it a good card?) and an Ethernet board. I am planning to order on ebay two 16mb modules, a 256kb cache dip module and a cf2ide adapter (planning to test other operating systems). Perhaps also a MPEG2 video decoder board.
Unfortunately this computer has a very weird problem, a problem for which I am doubtful if it has sense to plan all these upgrades or not. I remember when I was a kid (it was my granma’s computer) I played with it and I connected a PS/2 keyboard to it, a keyboard provided with a PS/2 to AT converter that was used at the time by my uncle on a very similar computer. That keyboard worked but, after that, a disaster has happened: this computer recognizes only that keyboard! I tried several working AT keyboards with no success, then a couple of PS/2 keyboards using that adapter and different adapters: nothing at all. I really cannot explain this thing. Now it is very problematic because I can use only that keyboard. The keyboard is an anonymous grey keyboard from early 2000s, it has no brand, only “Office Keyboard” on the top and “Smart keyboard” behind, “Made in China”, “Model No:Ez-9910”.
I have found in that same garage a mechanical IBM keyboard (perhaps the famous Model M, code is 1391404) with ps/2 connector: I tried it with several adapters on that computer but there is no way to get it working.
This is problematic because if the Chinese keyboard dies, then my Pentium will die with it. Moreover, I use this computer mainly for word processing (write stories) and, recently, I started a coding class and I really enjoy learning C on this computer. Now I am at the beginning, but I think very soon I will be able to try some mode 13h to write simple dos games (http://www.brackeen.com/vga/). I’d like to use the IBM keyboard, it is really a fantastic keyboard, but I can’t.
I don’t know if this can add some valuable info, but this computer has also another very strange “feature”: it is extremely sensitive to electrical (what, fields? I don’t know). That is, if there is something of “electric” happening on the same plug/room of the computer or I attach something to its ports, the buzzer will emit a sound. If I turn on the light in the room, sometime the buzzer buzzs and, if you don’t believe me I will try to replicate it and post a video, some days ago the top of weirdness happened: the computer was attached to its CRT Philips monitor via VGA Cable; my smartphone’s jack output was connected to Philips’ RCAs input for audio (I was listening to a coding lesson while programming on Borland 5 <3). PC, CRT and phone’s charger were all on the same plug. Well, if I moved the jack in the phone, then the buzzer made the sound. How is this possible? Bad insulation? Ground problems? Could it be related to the keyboard issue?
On this page: https://pcrebuilding.altervista.org/2/MOTHERB … D/SOCKET+5.html I have found several informations about the motherboard. Potentially, it has two connectors for PS/2 keyboard and mouse (CN1 and CN2), while now there is only AT keyboard (with the mentioned problem) and a very uncomfortable serial mouse. Moreover, I have found on the motherboard this table
JX1 AN6,7 RN5
EXT KB 2-3 ON OFF
INT KB 1-2 OFF ON
In the manual, JX1 is “Factory configured - do not alter”. I tried all the combinations but it didn’t solve the problem.
I am really frustrated by this issue. What could it be the cause? Could solder a ps/2 connector solve the issue? (but if I see the scheme it looks that at and ps/2 share the same contacts) Could I add an external controller in some way?
If you don’t understand something of my post tell it to me, I know my English is bad, sorry.
Thank you 😀