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From: omega@ut-ngp.UUCP (Omega.Mosley`)
Newsgroups: comp.sys.ibm.pc,comp.sys.att
Subject: Re: PC Jr. Questions
Message-ID: <5862@ut-ngp.UUCP>
Date: Mon, 10-Aug-87 19:42:42 EDT
Article-I.D.: ut-ngp.5862
Posted: Mon Aug 10 19:42:42 1987
Date-Received: Wed, 12-Aug-87 01:08:18 EDT
References: <2275@oliveb.UUCP> <661@ge-dab.GE.COM>
Distribution: na
Organization: UTexas Computation Center, Austin, Texas
Lines: 47
Keywords: disk display memory configuration XT-compatibility
Summary: Speaking of the Jr...
Xref: mnetor comp.sys.ibm.pc:6582 comp.sys.att:924

In article <661@ge-dab.GE.COM>, byrnes@ge-dab.GE.COM (Arthur J. Byrnes) writes:
> >
> >	Pardon my ignorance.
> >	I want to know if PC Jr.'s can read and write MS-DOS 5.25" floppies.
> >	Also, can PC Jr.'s work with programs expecting  Color Graphic Adapter.
> The PCJr writes IBM standard double sided 360k floppies.  

...it also writes single-sided as well, but I'm not sure about the 1.44 meg
format. Also, unless IBM has solved the problem, the Jr will not format 3 1/2"
disks under any circumstances despite the fact it will read the blasted things.
there was once a twin-drive undercarrage available for the Jr, but reportedly
never sold because of the DOS problem. This was too bad, since the unit only
cost 199 bucks (99 when it was phased out last May) for two drives and the
controller (it replaced the 5 1/2 one, tho...)

> The graphics adapter is fully compatable with the CGA card on an xt/pc.
> Be sure to use the bios interface when programming, (this is great aadvice
> to any programming done for the IBM and clones.)

...this is true, however many software developers are now ignoring some of the
BIOS calls that prodice different results when used in the Jr rather than an
XT. This takes any redefined ASCII graphics and retranslates them back into the
original form. Two games, Space QUest and Pinball Construction Set, are notorious for this problem, and thier developers really have no interest in helping the
Jr user in fixing the problem.

> The "standard" configuration for the jr is 128k memory. It can be 
> expanded to the full dos limit, 640k, but only using special add ons
> which may or may not still be available.

...actually, to boost your Jr to 640k, all you need is a sidecar (IBM's or
Techmar's. This will not work on Microsoft's Mousecar), 18 256k chips, a
jumper wire, a pair of dykes (nonono...Diagonal Cutters, you twit!), Soldering
(pronounced SOL-DER-IN') Gun, Solder, Vaccuum pump, and a LOT of patience.
Once you get these, if I can figure out how I'll post up a doc file on how to
install teh new chips. You will also need a file called PCJRMEM.COM, which is
installed mby CONFIG.SYS, and will only work with DOS 2.1. This may pose a
problem, but how many Jr. owners have a hard drive?

> >	What other incompatibilities to PC XT that you know about.
> The XT has very poor sound when compaired to the Jr.
> But if the programmer has done his job properly, and not tried to
> prove how well he can avoid the bios 1/3 :-), any program should 



                                    Omega.Mosley
				    ...who owns a Jr and is damn proud of it!