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Solve : Comtex Turbo XT computer.? |
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Answer» hey all. OTOH, there are "upgrade" things that allow you to force a 286 onto a XT. Can't remember if that was a card, or what.This by the way did not make much sense to me. I don't see how one could force a 286 (processor) onto a XT. Unless you meant forcing a 286 OS onto it. Okay, thanks so much, I am not at all really familiar with computing in the 80's. I have no clue what things like an "ISA slot" or a "MDA plug" is. I've attached a bunch of shot of different parts of this PC so you can tell me a bit more. Hope this help. ----------------------------------------------------------------------------- Picture Guide: Picture1 - Graphics card I believe Picture2 - Motherboard and cards Picture3 - a card (don't know what kind), with 2 port on it that were labeled "Game Port" & "LTP2" in picture "Picture 0088.jpg" above. Picture4 - another card Picture5 - all 3 cards Picture6 - the complete inside of the PC [Saving space, attachment deleted by admin]here are the last 2 pictures (did not fit in last post). [Saving space, attachment deleted by admin]Quote from: BC_Programmer on October 12, 2009, 04:51:03 PM I would say the video card (I can almost assure you it's the card on the right) is an ATI EGA Wonder, since it has dip switches. IIRC that was a 8-bit ISA card.Well it says EPG right under the dip switches.Coool... regarding the 286 upgrade, I'm not sure exactly how it worked, but it was in later XT models... it was some kind of card, that had a 286 processor, and you installed the driver and you could run 16-bit programs that otherwise would need a 286. Not sure exactly how it worked or how well. An ISA slot was the slot used before PCI (obviously ) and was found on the first IBM PC as well. it came in 8-bit and 16-bit varieties, the 16-bit being first found on 286/AT class PCs. the 9-pin connector on the video card is either MDA, MGA, or CGA, which were different display technologies predating the VGA 15-pin plug. (I think EGA used 15-pin, but I'm not sure... checking... I was wrong- EGA also uses a 9-pin connector- if I had to guess, I would say that was what it was- something like the ATI EGA Wonder of the time, which had connectors like those funky video in/out on that card.) MDA could only display text, and the monitors were often either black and white, or sometimes even lime green or amber. MGA had a graphics mode on top of the ability to display simply text characters, mostly thanks to more video memory for addressing each pixel (80x25x2 bytes (1 byte for the char, another for attributes) characters only take about 4K of Video RAM, whereas addressing each pixel of the 720×348 would require one bit- therefore around 30K of Video RAM.) Picture one: definitely the video card. I believe the 9-pin output is either MDA,MGA, or CGA. (it could also be EGA...) you won't find those monitors around anymore, so if you don't have one you'll need to find a 8-bit VGA card on ebay, or something... (or a monitor, if you're feeling bold, but those might be costly for shipping). as for the second card, this is the Controller card. I can't really tell, if it's IDE in this picture, I can only count 34 wires (confirmed by the other pic that has 34 pins) on the larger ribbon. the floppy cable is there though. This overview tells us that there are no 16-bit ISA slots, which posess two connector tabs. This means, as I originally suspected, that the PC is not AT class at all, and posesses a 8088 or 8086 processor. (probably the newer 8086, given it is labelled as an "XT"). as a history lesson, it wasn't until about the 486 that we got integrated motherboard hard drive and floppy drive controllers, Com ports, or the like; prior to that one needed a Controller card for their Drives, a I/O card for parallel and COM ports (which is what your card installed closest to your PSU is. (notice the connector at the front bottom of the card being one of the serial ports) The hard drive is ESDI- ESDI has a 34-pin interface, I believe. Moving to the motherboard- I notice, in the lower left, that not all the memory DIPP's are occupied. I'm not sure how much there would be there, I only see 11 slots, 3 of which are occupied. However, I will further guess that since the total possible RAM in a XT is 1024KB, that there are actually 16 slots, which hold 64KB each. This means, that there are 5 slots not shown, possibly under the ribbon cable; Don't know if these are occupied or not. This means that if they are empty, you have 3*64KB, or 192KB; or 7*64KB=448KB. Not sure, how well it'll work for your intended purpose- I doubt there are many games at all that will run with this machine, since even something like commander keen NEEDS a 386 :/ Definitely something to learn from though So is this like a clone of the "IBM XT"? http://en.wikipedia.org/wiki/IBM_PC_XTQuote from: BCP (probably the newer 8086, given it is labelled as an "XT"). XTs had 8088 cpus - I had an Epson Equity+. The "Turbo" indicates it can run at either original 4.7 MHz or some higher speed 8 or 10 MHz usually selectable via a switch accessible externally. 286 upgrade cards fitted in an ISA slot and had a ribbon cable ending in a connector that fitted in the old 8088's socket. They were not always very reliable. Before the ZIF socket for CPUs, removing a processor was a tricky affair, often resulting in a few BENT pins on the CPU. I remember doing 2 CPU upgrades where the old CPU was pulled out and the new processor, and some supporting chips, was on a daughter board that plugged into the old CPU socket. One worked fine and the other crashed a lot. |
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