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rmjay
February 20th, 2017, 04:19 PM
Hello,

I have an AT&T PC 6300 that I got to run yesterday, other than a dead battery, and the floppy and hard drive having issues, it seems to function.
The questions I have are:

Can I use a 10 mhz NEC V30 in it?

Can I use any 8087 in it? Not just an 8087-2?

Can I just remove the battery on the motherboard and leave it off?

Would it be possible to change out the hard drive for a CF to IDE adapter? It has a Tandon hard drive and controller card.

I have a Citizen GSX-140 printer that I would like to hook up to it, can I just plug it in and use it? Or do I need some special driver?

Is it possible to run Windows/286 on this computer with the monochrome monitor?

Sorry for so many questions, but I don't know a ton about this machine, and I would like to actually do something with this computer.

Thank you

MrArgent
February 21st, 2017, 08:08 AM
Can I use a 10 mhz NEC V30 in it?
The CPU isn't socketed, so you'd need to be handy with a soldering iron, but theoretically it's doable!

Can I just remove the battery on the motherboard and leave it off?
Yup, and frankly that's the best option. If improperly stored, battery leakage can be positively catastrophic for a 6300... to "bricked system" extremes!

Would it be possible to change out the hard drive for a CF to IDE adapter? It has a Tandon hard drive and controller card.
Honestly, I've been wondering about that myself. There's apparently no reason a XT-IDE won't work, from what I've hard.

Is it possible to run Windows/286 on this computer with the monochrome monitor?
Yes, in fact! It'll run pretty well in Windows/86 (i.e. Real mode) mode. Be sure to use the AT&T native video option in setup for the best results!

glitch
February 21st, 2017, 08:37 AM
Would it be possible to change out the hard drive for a CF to IDE adapter? It has a Tandon hard drive and controller card.
Honestly, I've been wondering about that myself. There's apparently no reason a XT-IDE won't work, from what I've hard.

It's my understanding that the "Chuck Mod" won't work with the AT&T 6300, so you'll need a card that has jumper select for "Chuck Mod/Compatibility" modes. Any of the N8VEM boards or the current N8VEM-based XT-IDE rev 3 will work here. I've still got plenty of XT-IDE rev 3 boards, kits, and assembled units if you need one.

Chuck(G)
February 21st, 2017, 08:58 AM
Can I use a 10 mhz NEC V30 in it?
The CPU isn't socketed, so you'd need to be handy with a soldering iron, but theoretically it's doable!

It's worth checking--the CPU was socketed on my board and there's a V30 running in it now. Never used an 8087 with it (for what?) but it should work.


Can I just remove the battery on the motherboard and leave it off?

I replaced the NiCd battery on the motherboard with a lithium coin-cell holder in series with a diode. Works fine.

As far as printers go, you should be able to electrically interface any printer with a serial or parallel interface.

Glitch is right about the "chuck mod" not working. The 6300 has its own circuitry to translate 8 bit I/O requests to 16 bit--and it does it the opposite of the 8088 BIU. However, disabling the "chuck mod" works well, albeit not as fast as the mod.

rmjay
February 21st, 2017, 12:07 PM
So if I remove the battery all together all that would happen would be it says fail during POST, and I have to enter the date every time I start it up, right? And the 8087-2 is a math coprocessor.

rmjay
February 21st, 2017, 12:25 PM
Also, does anyone know if the Tandon controller card would work with a Seagste, or something else.

Thanks

Chuck(G)
February 21st, 2017, 12:57 PM
So if I remove the battery all together all that would happen would be it says fail during POST, and I have to enter the date every time I start it up, right? And the 8087-2 is a math coprocessor.

That's right--that's why I recommend a coin-cell-and-diode replacement. The holder will keep the cell off the PCB, and, since it's inverted, any leaks will drip down.

My comment about the 8087 was that, outside of spreadsheets and the very early CAD stuff, there really wasn't a whole lot in the 8088 era that could take advantage of it. In general, if you add it, you won't notice much difference in overall performance.

AlG
February 21st, 2017, 01:37 PM
I've got the Olivetti branded version (M24), and can second that the CPU on my unit is socketed. I'm considering trying a V30 in my unit, but haven't gotten around to it yet.

Trixter, has written a guide to Beefing up your AT&T PC 6300 (https://trixter.oldskool.org/2008/04/22/beefing-up-your-6300/), that includes the use of a V30, it's worth having a read if you haven't seen it yet.
I've got the math co-processor, but it was installed before I got the computer. Your software probably won't use it, but if you've got one lying round you might as well install it ;)

- Al

1ST1
February 22nd, 2017, 05:51 AM
All my three M24 (it's not branded, it's original, the 6300 is rebranded) have socketed 8086. At the times ind the 80's it was quite popular to replace it by a V30.

For 8087 you need to take care that it can run stable at 8 Mhz. There are also 4, 5 and 6 MHz types which get too hot on 8 Mhz. So you need an 8087-1 or 8087-2. Also some games like MS-Flightsim use the 8087 as soon as there is one.

You should remove the battery. If you don't have a modern replacement, the only problem you will have that at every power on the time+date is wrong.

Harddisk replacement: XT-IDE or XT-CF card from lotech is your thing.

Printer: As long as it has standard centronics interface and supports Epson ESC-P or IBM Proprinter control sequences you can use it with all software. There is no central driver management under MS-DOS. But GEM and Windows 1.0, 2.0 have central printer driver management like we do know it still today.

Windows for Intel 80286 on XT clone with 8086 or V30? I have my doubts... But there is also 8086/8088 version of Windows 1.0 and 2.0. And there is (Free-)GEM.

glitch
February 22nd, 2017, 06:01 AM
Harddisk replacement: XT-IDE or XT-CF card from lotech is your thing.

Someone correct me if I'm wrong, but I believe the current version of the Lo-Tech XT-IDE has a permanent "Chuck Mod" and won't work in the AT&T 6300.

Chuck(G)
February 22nd, 2017, 08:58 AM
I don't know, but it's simple to recompile the XTIDE BIOS with the option disabled.

rmjay
February 22nd, 2017, 10:21 AM
So, I managed to snag a ST-225 with a controller card, if that doesn't work, I'll look into this CF thing more. When it comes to the battery, can I just cut it from the socket using a small wire cutter, or do I have to fully desolder it? Also if I got an 8-bit ISA Ethernet card, could this computer actually do anything on the internet? I noticed it's kind of hard to find a Ethernet card that still comes with drivers on a 5.25 disk.

Thanks

Trixter
February 22nd, 2017, 11:49 AM
Can I use a 10 mhz NEC V30 in it?

Yes, and this is recommended for a modest speed boost, unless you want to run Geoworks Ensemble. For some reason, Geoworks Ensemble locks up if an NEC V30 is installed in a 6300.


Is it possible to run Windows/286 on this computer with the monochrome monitor?

I don't think Windows/286, but Windows 1.0 and 2.0 work fine, and even support the 6300's 640x400 mode.

Geoworks Ensemble is the most impressive GUI you can run on the system, but see the note above about the NEC V20.


So if I remove the battery all together all that would happen would be it says fail during POST, and I have to enter the date every time I start it up, right?

No, nothing bad happens if you remove the battery. The 6300 is based on the 8086 and does not have battery-backed CMOS settings. The only thing you'd need to do is enter the date every time it boots, that's it. You should remove the battery to prevent it leaking acid all over the board and ruining it.

noppa
February 22nd, 2017, 04:28 PM
If you can read italian there's some fun at page 41

www.introni.it/pdf/Elettronica%20Flash%201991_02.pdf

rmjay
February 23rd, 2017, 10:53 PM
Could a VGA card be put into one of these computers? I was just curious

AlG
February 25th, 2017, 02:11 AM
I believe installing a VGA card should be possible, but you'll need BIOS version 1.43 (the latest version). This is mentioned in the Italian document linked above. I'm not sure of all the required steps though.
Your machines current BIOS Revision appears at boot up.

The original video card is an integral part of the machine, connecting the motherboard to the ISA ports, so I'd guess the existing graphics board would need to be disabled somehow (but I'm not sure). Hopefully somebody else here has done it and can advise.

Stone
February 25th, 2017, 03:36 AM
You should remove the battery to prevent it leaking acid all over the board and ruining it.Acid?

These batteries, when they leak, emit a base. Unlike car batteries, they operate in a basic internal environment.

But, yes, bases are also corrosive, e.g., lye.

DDS
February 25th, 2017, 05:15 AM
Acid?

These batteries, when they leak, emit a base. Unlike car batteries, they operate in a basic internal environment.

But, yes, bases are also corrosive, e.g., lye.

I second what Stone says. He's not just carping on detail. Part of a successful clean up of any chemical spill is using an agent to neutralize any active hazardous materials. If you don't, any material you have not completely removed from the spill site will continue to do damage.

In short, in cases involving battery spills you start with knowing the chemistry of the battery involved in the spill. Next neutralize an acid spill with a weak base (common glass cleaners containing ammonia will work) or neutralize a base spill with a weak acid (vinegar or lemon juice). Finally flush the area if possible with distilled or de-mineralized water and allow to dry.

Chuck(G)
February 25th, 2017, 08:52 AM
In my machine, (1.43 BIOS), a VGA card was enabled by removing a socketed PAL on the video boards--and unfortunately losing it. (See my blog on cloning PALs).

rmjay
February 25th, 2017, 09:06 AM
My BIOS is 1.21, anyone know where I can get a 1.43 chip? The green screen monitor on my machine is starting to go bad, the text gets all flickery and wavy, and there are diagonal lines appearing on the bottom and right of the screen, like its not centering the image.

AlG
February 26th, 2017, 07:58 AM
I'm not sure about the monochrome monitors, as my system has the colour CRT unit. It sounds like upgrading you BIOS and switching to VGA is one possible solution to your display issues. Unless you want to keep the green-screen ;)
In regards to the BIOS upgrade, the EPROMs sometimes appear on eBay. I’ve recently purchased some to upgrade my M24. Otherwise the images can be downloaded from the web and burnt to two EPROM chips. I don't own an EPROM burner, so I just waited until some appeared for sale.
You could see if anyone else on here is able to sell you some pre-programmed EPROMs or just set up some eBay searches. I believe the BIOS version is common across the AT&T6300, Olivetti M24 and Olivetti M21.

I've just upgraded my M24 BIOS this weekend. It's gone relatively smoothly. Although I did encounter one issue, Following the upgrade, the system hung after POST while displaying :'Optional ROM at C800:0000'
It would successfully boot off a floppy, if I removed the hard-disk controller card.
I found some western-digital documentation that discussed an incompatibility with the AT&T 6300.
http://www.minuszerodegrees.net/manuals/Western%20Digital/wdcontr.txt


"The AT&T 6300 and the AT&T 6300 PLUS contain system BIOS
chips that support the hard disk drive. When using a Western Digital XT
controller card the system will not "boot." To solve this problem, one of the
ROM BIOS chips must be disabled. To disable the BIOS on your Western Digital XT
controller card, you must remove the jumper at position W-3 or add a jumper at
position R-23 (depending on which model of XT controller you are using)."

Whatever this issue is, it was obviously introduced in the later BIOS versions. I'm assuming the additional on-board hard disk support was added to these later versions.
I had to solder a resistor across R23 on the controller card. Since no value was given, I guessed at 100 Ohms based on the other resistors on the board (if anyone reading this, knows the right value for a WD1004A-WX1 let me know). It appears to be working so far.
I thought I'd mention it in case anyone else come across it. I don’t know if there’s also a Motherboard setting that would have resolved this.
In my case, I’m not having any display issues, but I had hoped the BIOS upgrade would allow me to install a spare SoundBlaster-16 (CT1740) into the computer, as I've heard this works in an 8-bit ISA slot. However, I still can't get the system to boot with both the SB-16 and HDD controller plugged in. Although this was happening before the upgrade, so I may just need a true 8-bit soundcard.

1ST1
February 26th, 2017, 10:35 AM
My BIOS is 1.21, anyone know where I can get a 1.43 chip? The green screen monitor on my machine is starting to go bad, the text gets all flickery and wavy, and there are diagonal lines appearing on the bottom and right of the screen, like its not centering the image.

The M24 graphics card outputs analogue RGB H+V-Sync which is understood by any VGA monitor. There is an instruction/pinout of the DB25 connector on et 6300 shrine website, so you can solder an adapter.

About the issue with the harddisk controller: Olivetti originally uses MFM controllers which have no BIOS, so removing/disable the BIOS chip is a solution. Maybe it also works if you tell the M24 that it has no harddisk with the onboard DIP switches, I never have tryed this!

pietja
February 26th, 2017, 11:05 AM
The green screen monitor on my machine is starting to go bad, the text gets all flickery and wavy, and there are diagonal lines appearing on the bottom and right of the screen, like its not centering the image.
I had the same issue with my green screen monitor, i have replaced all the electrolytic capacitors in the monitor and adjusted all the internal trimmers to get i stable again.
If you going to do that keep in mind that one capacitor is a high current bipolar one that is hard to find new, also you have to be careful with the high voltage.

rmjay
February 27th, 2017, 11:42 AM
It sounds like I am going to have to create a VGA adapter cable.

rmjay
February 27th, 2017, 01:23 PM
I just found the VGA adapter information on the shrine, is the pinout the same for a standard VGA plug, the smaller one?