Jump to content
IGNORED

Found a 130XE with a hacked OS ROM...


Recommended Posts

Thought I would offer it up here. The differences that are apparent:

 

- Screen is a darker shade of blue.

- Cursor is moved all the way to the left

- Function of Option key is flipped: if not held down BASIC is off, if held down BASIC is on

 

When compared through a hex editor it was closer to the Rev 2 XL OS than the Rev 3 XL/XE OS.

 

There were 974 differences with the Rev 2 XL OS.

 

I attached the dump of the ROM and the report file. The ROM seems to work OK in Altirra.

 

Have fun!

xl-xe-rom-16k-27c128-modified.rom

Report-130XE-mod-OS_vs_XL-Rev2.txt

Edited by firebottle
  • Like 4
Link to comment
Share on other sites

I noticed that the Marslett Fast Math isn't there. IIRC the real US+OS has readable

ascii copyright notifications instead of having it in internal form or however

rdea6 showed those notices, I don't see them in my PC hexeditor in other words and

seem to recall no issues with the genuine US+OS in that regard.

 

I'm in the same boat with TXG/MNX on this one, kinda iffy. But thanks for sharing,

would like to know what it is/does too.

Link to comment
Share on other sites

Thanks to the XL/XE appendix in Mapping the Atari, I see that the area with the most changes is where the international font is: 0C00-0FFF in the ROM, CC00-CFFF in memory. Using Altirra's debugger, the code has a lot of device equates like DSTATS, DCOMND, DUNIT, etc.

 

The standard font area (2000-23FF in the ROM, E000-E3FF in memory) has a few characters changed: a fatter exclamation point, a right facing double quotation mark, a right facing single quotation mark and a thicker caret... thanks to Compute's 3rd Book of Atari.

 

There are two bytes changed in the handler code area (095C-095D in ROM, C95C-C95D in memory) which are part of jump instruction (JSR CC00).

 

In a routine at 3348 to 3365 ( F348 to F365 in memory) there are changes to the branching behavior involving the Caps key. I don't see any difference using BASIC.

 

Also looking at the XL Rev 2 ROM source code posted elsewhere on AtariAge forum, there are changes in the "preset memory" area (036D-03AC in the ROM, C36D-C3AC in memory): C36D is the margin setting... LEDGE is changed from 02 to 00, C383 to C388 has changes to a setting of the key repeat rate to a JSR CFB2 (???), and in the "check for memory problems" code... C3AB-C3AC changes from LDA NGFLAG (or rather, LDA $01) to LDA #$BF... don't know what this is doing.

 

049D is the option key change (C49D) and 3B09 & 3B0A are the color changes (FB09 & FB0A).

 

Playing around with two 130xes, an SIO2PC serial cable and Atari810 software, I noticed that switching serial speeds in the program worked with the modified ROM 130xe... 2x was OK, 3x crashed eventually. The normal 130xe... the speed stayed at 1x. Using Aspeqt, the speed was even faster and didn't crash at 3x.

Edited by firebottle
  • Like 2
Link to comment
Share on other sites

I found this, but I'm thinking it's wounded due to hardware data showing in the self test area

which means it was an unsophisticated rom move and write to file operation without the

really necessary things done to capture the self test portion.

 

http://ftp.pigwa.net/stuff/collections/nir_dary_cds/ROMS/ROMS_OS/MISC/ULTRAOS1.EPR

 

But it will show enough that this isn't that one. Interesting detective work, thanks.

Link to comment
Share on other sites

I'll check but I don't think I have the source code for that ROM. I have the source code for the hi-speed SIO that Bob used in various things because he gave me a copy for the backup program I did for CSS. For the CSS stuff I generally only have the source code for things I was involved with. I'm pretty sure I don't have source for a whole ROM of anything that Bob did, but I will have a look.

Link to comment
Share on other sites

It matches my copy of the Ultraspeed OS from C.S.S. At least the SIO code at offset $0C00 is the same and so is the copyright notice at $0CF8.

Some confusion exists as to which rom you are saying is a match. I'm positive the file

link I posted is Bob's OS (US+OS) as can be read in ascii within it. My nickname for it,

perhaps a little cruel is BOBOS because of that unique text snippet in there.

And this is not the mystery OS that concerns the thread title here.

 

However this US+OS file is also broken and can never work as intended - it's a bad copy.

It would be a waste of time putting this on an eprom and trying it, if it did boot,

it wouldn't be long before something went sideways with it.

 

I do believe that you are correct with "CSS Multiplexer slave machine" OS though.

Or master, I don't know how those work either. I assumed all the slaves could

be standard machines and again I really know nothing about it.

Link to comment
Share on other sites

I have two rom files, ultraspd.os and ultra.xl and your rom seems to match the first.

 

A multiplexer host machine can be a stock xl because the host software will drive the mux card, whereas a slave machine requires a custom rom. I'd have to pull up the patch source, I don't recall offhand whether it's the international char set or the cassette handler that gets deleted to make room for the slave handler.

Link to comment
Share on other sites

  • 1 year later...

Necrobump.

I came across a 130XE with the Omnimon XE installed. The old BBS operator for Action Annex used it to fix and tweak things. I noticed on archive.org the manuals and docs for the XL version. I have two old eproms also that appear to the be the 400/800 version (white label, red text, no version number)

As I restore some of the 800s I will test the rom and see what it is exactly. I was thinking of just putting it in the cart slot to read it on the 130xe Omnimon.

Also, in this collection is an Omniview card for an 800.

I can dump the Omnimon XE rom for anyone that wants a copy. I am not sure where it loads exactly, I do know the switch to toggle it on and off works. I need to dust off my copy of "mapping the Atari " again after 30 years.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...