Visit Atarimax Store


Free-Net Logo
The Atari SIG Historical Archive
Created and hosted by: atarimax.com
[ HOME | GO ATARI | 8-BIT | ST/TT | PORTFOLIO | LYNX | JAGUAR | LIBRARY ]


Article #61 (75 is last):
From: aa700@cleveland.Freenet.Edu (Michael Current)
Newsgroups: freenet.sci.comp.atari.prog.8bit.resource
Subject: Drive info and expanded ram info needed
Reply-To: aa700@cleveland.Freenet.Edu (Michael Current)
Posted-By: xx004 (Atari SIG)
Date: Sat Nov 15 17:50:13 1997


From: rje@co.umist.ac.uk (Raphael James Espino)
Date: 14 Oct 1997 12:43:10 GMT

Ok.. I've posted this once and apart from dklugh trying it out on an emulator
(thanks) I've had no answers to this request, so lets try again.

I would like to get hold of the configuration block info returned by various
Atari drives.  The stock 810 and 1050 don't have one, so no problem there.
I've got the info from a Happy 1050, and now I'm looking for info from other
drives, in any configuration they support, especially double sided drives.

You can get hold of a simple program I wrote to return this info from
my web page: http://www.co.umist.ac.uk/~rje/8bit/readcfg.txt 
or e-mail me for a copy.

So why do I need this info?

Well... I've been working on a new ramdisk program which will be DOS
independant and work with most types of expanded RAM.  So far I've got it
working under MyDos, Dos 2.0, 2.5 and even the much maligned 3.0 (it was
really cool switching back and forth between the various menus instantly).
The way it works is by making the ramdisk look like a real drive to DOS,
so any DOS should be able to use it without being hacked, even if it doesn't
have ramdisk support built in.  Hence my request for the above info.
Of course if you only have 64K extra ram, then not even a SS/SD disk will 
fit (you need at least 90K for that) so you can also set up custom sized
ramdisks (so you could set it up for DS/DD even if no one sends me the info,
but still I'd like to include it as a default).  And you can have multiple
ramdisks set up, so if you want to use your 1Meg ram with Dos 2.5 then you
can just set up as many ramdisks as you need (up to a maximum of 10).

It should be able to handle any size of ramdisk too, I've tested this with
a 256K and 1Meg XE and it works.  It should also be able to handle an 8K
ram under BASIC rom ramdisk (although I haven't tested that yet) so if you
haven't got expanded ram you can still have a (very small) ramdisk.

Now for the downside... the code uses the ram under the OS so it won't work
with anything else that does too (most Spartados versions, TurboBasic and
others), and it won't work with 400/800's either unless they can be modified
to have that same ram under OS as XL/XE's do. 

Mmmm.. while I'm at it what other types of memory expansions are there around
for XL/XE machines?  
I know about the standard XE type (16K banks appearing at 16,384 to 32,768,
bank switching at 54017 using various bits for different ramdisk sizes)
Are there any other types of expanded ram?
What are the bank sizes? where do they appear?  what address is used for
switching?  what bits are used?
Also what bits are used in 54017 for other XE ramdisk sizes? 128K? 192K?
512K? etc...

Once I've got this working I'll put the program up on the net so that anyone
who wants a copy can get one.  And I'll be looking for people to test it out
on different machines with different Doses.  So the more info I get now the
more systems will be supported.

Ta..
--
Raphael Espino - rje@co.umist.ac.uk
-- 
Michael Current, mailto:mcurrent@carleton.edu
8-bit Atari FAQ and Vendor Lists, http://www.faqs.org/faqs/atari-8-bit/
Cleveland Free-Net Atari SIG, telnet://freenet-in-c.cwru.edu (go atari)
St. Paul Atari Computer Enthusiasts, http://www.library.carleton.edu/space/


Visit Atarimax Store