Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!cbosgd!mandrill!neoucom!wtm From: wtm@neoucom.UUCP Newsgroups: comp.sys.ibm.pc,comp.sys.att Subject: Re: 6300 bugs? Message-ID: <709@neoucom.UUCP> Date: Mon, 28-Sep-87 00:07:47 EDT Article-I.D.: neoucom.709 Posted: Mon Sep 28 00:07:47 1987 Date-Received: Thu, 1-Oct-87 00:55:14 EDT References: <290@gvgspd.UUCP> <862@sask.UUCP> <1409@homxc.UUCP> Organization: Northeastern Ohio Universities College of Medicine Lines: 99 Xref: utgpu comp.sys.ibm.pc:7316 comp.sys.att:1158 Summary: Adding an EGA card isn't too bad... << Re: stuff about an EGA card being a pain to run in the AT&T 6300 >> Well, I'm writing this from an AT&T 6300 running with an EGA card. I didn't think "ugrading" to an EGA was too awful. First, old versions of the 6300's BIOS did not test for the presence of the EGA BIOS. Anybody remember the old IBM XT's made before March, 1982? They couldn't use EGAs either. AT&T isn't the only company that has improved its BIOS over the years. Update your 6300 by calling 1-800-222-PART. Just ask for the version 1.43 BIOS chip set. They'll know what you want, so you don't even have to scrounge for the infamous AT&T com item number!! They'll accept Visa/MC and ship it to you within 7 days. The cost is aobut $35.00 US. The kit includes two ROMs and a PAL chip. It takes about 10 minutes to install the chips. The instruction manual is pretty clear about what to do. If you are just updating the BIOS, you don't need to change any of the dip switch settings. The PAL chip fixes a bug related to putting out the bytes of a 16-bit OUT instruction in reverse order. Since the 6300 was actually desinged before the AT hit the market, AT&T just happened to pick the opposite order of IBM for 16 bit OUTs. AT&T has become IBM compatible as of v 1.43. Note that some EGA cards use 16 bit OUTs (eventhough designed for an 8 bit buss) when they shouldn't. They intend for the unneeded 8 bits to fall off into never-never land. Unfortunately, old 6300s kept the garbage and threw away the real data. -- While you have the bottom cover off, try substituting a NEC V-30 vor the original 8086-2 CPU. Integer mults are performed in 1/2 the number of clock cycles on the V-30. A very noticable performance boost results. I have had a V-30 since Jan 21, 1987 in my 6300 and have nary an ill experience with it. It is also fully compatible with my 8087-2. I wish I could say nice things about the V-20 like that w.r.t. subbing for an 8088. Elec-tek has V-30s for about $12 + S/H. Very much recomended. -- If you are installing an EGA card. You might want to consider getting the STB Co. "Multires EGA". You should be able to find it for around $230 or so. It has modes that allow it use the AT&T color monitor in full EGA display mode. Neat. Actually, I had a Taxan 640 which is a clone of the AT&T monitor. You need to make a small adapter cord to go from the db-9 on the STB card to the 25 pin cord of the AT&T monitor. If you aren't electrically adept, the cord should be available from STB. If you don't have an "investment" in an AT&T color monitor. You should be able to use most any EGA card and EGA monitor. -- There are two methods for shutting of indigenous video on the 6300, which you must do to enable an EGA card. If you have a relatively recent 6300, moving the jumper, W1, near the front of the bord next to C11 will disable internal video. W1 should be on pins 1&2. By the way, these boards are indentified as version P8. On older machines, a 74LS00 IC must be pulled from its socket and a header installed. These boards are indentified as P4. The offending 74LS00 is in a socket near the bottom of the board right above where the thick red&black wires attach to the buss adapter. On some particularly ancient 6300s, the 74LS00 might be soldered in (ugh!!). The header to install in place of the 74LS00 is as follows: jumper pin 3 to pin 14 jumper pin 6 to pin 7 to pin 8. leave every other pin unconnected. (The above info on making the header comes from Mike Slifcak of Olivetti ATC.) Neither Mike nor I can take responsibility if you burn up your computer trying this. If you have any reservations about your abilities, by all means, get somebody that knows about electronics to assist you. -- I really like my 6300. It is still my favorite MS-DOS (gurgh!) machine. Unfortunately, AT&T / Olivetti / Xeorx were just a bit ahead of their time bringing it out. At the time the 6300 made its debut, most PC buyers were more than satisfied with the lumbering, noisy 4.77 MHz XT. I mean buyer, in the sense of coportate buyer. The corporate mentaility was locked in by IBM f.u.d., and wouldn't risk anyting like a 6300 when the XT would do the job. --Bill Bill Mayhew (wtm@neoucom.UUCP)