Subject: RXB problem

From: "Michael Zapf" <[email-masked]>
Date: Thu, 31 Jan 2013 12:54:12 -0000

By chance I noticed that RXB in all its versions is not running in MESS anymore, and I eventually found the problem:

I classified the cartridges as "paged", which means an Extended Basic scheme with *6K GROMs*. Due to a glitch in the implementation, the check for 6K was broken, and when I fixed it about a year ago, the modules stopped working - unnoticed. 

RXB seems to access GROM space at "illegal" locations (like 7e00). So I conclude the cartridge does not use real GROMs but a GROM simulator which allows for accesses in the complete 8K space.

Is it so? Do we have more cartridges that have a GROM simulation? (emulation, whatever :-) )

(Not the cartridges with RAM area paging.)

Michael

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From: [email-masked]
Date: Thu, 31 Jan 2013 13:29:13 +0000

All the non-TI XBs use 8k groms to the best of my knowledge, Michael. I know that XB v2.5 and SXB do for certain. 

Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: "Michael Zapf" <[email-masked]>
Sender: [email-masked]
Date: Thu, 31 Jan 2013 12:54:12 
To: <[email-masked]>
Reply-To: [email-masked]
Subject: [TI994A] RXB problem

Michael

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From: "Michael Zapf" <[email-masked]>
Date: Thu, 31 Jan 2013 14:08:27 -0000

> All the non-TI XBs use 8k groms to the best of my knowledge, Michael. 
> I know that XB v2.5 and SXB do for certain. 

I suppose these use no real GROMs but EPROMs with some control circuitry which makes them look like GROMs.

As far as I know there have never been 8K GROMs. Were there any GRAMs, by the way? Again, not RAMs that pretended to be?

Michael

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From: "Tursi" <[email-masked]>
Date: Thu, 31 Jan 2013 10:21:38 -0800

I don't think RXB was ever released as an official cartridge, just as GROM 
files (not positive though). But there are a number of such modules that 
took advantage of the GROM emulators' 8k blocks. (I just got a neat one sent 
to me yesterday called Multimodule. ;) ) It's hard to know these days which 
ones were physical and which were just intended to be loaded into an 
emulator (simulator). ;)

Rich is active at the AtariAge group and released a 2012 update to RXB, 
including new documentation and new features, for anyone interested in that. 
Also videos of the new features.

http://www.atariage.com/forums/topic/163627-rxb-rich-extended-basic/page__st__50

-----Original Message----- 
From: Michael Zapf
Sent: Thursday, January 31, 2013 4:54 AM
To: [email-masked]
Subject: [TI994A] RXB problem

By chance I noticed that RXB in all its versions is not running in MESS 
anymore, and I eventually found the problem:

I classified the cartridges as "paged", which means an Extended Basic scheme 
with *6K GROMs*. Due to a glitch in the implementation, the check for 6K was 
broken, and when I fixed it about a year ago, the modules stopped working - 
unnoticed.

RXB seems to access GROM space at "illegal" locations (like 7e00). So I 
conclude the cartridge does not use real GROMs but a GROM simulator which 
allows for accesses in the complete 8K space.

Is it so? Do we have more cartridges that have a GROM simulation? 
(emulation, whatever :-) )

Michael

------------------------------------

Yahoo! Groups Links

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From: [email-masked]
Date: Sat, 2 Feb 2013 11:17:38 +0000 (UTC)

RXB was written using GKXB as a core. 
SXB and many other all use 8K GROMS. 
TI picked 6K GROMs and no one made these chips but TI. 

RXB is just like all the other Extended Basic versions. 
None of them use 6K GROMs. 

Rich 

----- Original Message -----
From: "Michael Zapf" <[email-masked]> 
To: [email-masked] 
Sent: Thursday, January 31, 2013 4:54:12 AM 
Subject: [TI994A] RXB problem 

Michael

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From: "Michael Zapf" <[email-masked]>
Date: Sat, 02 Feb 2013 11:51:59 -0000

HI Rich,

> None of them use 6K GROMs. 

except for the TI Extended Basic, of course.

To be more specific, my question was whether there were real 8K GROMs (as a chip, like the TMC0430). I would guess the cartridges you mentioned had an EPROM on board with some circuits that made the EPROM look like a GROM to the console, and that way you easily got an 8K space.

Michael

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From: [email-masked]
Date: Sat, 2 Feb 2013 11:56:17 +0000 (UTC)

Yes, the OPA POP cart and the Competition Computer Cart did this. 
Also Asgard made a RXB cart I think or someone that worked with Asgard said they did. 

There was also a build your own single GRAM cart project that some people used to make RXB carts. 
So yes they emulated a GROM. 

Rich 

----- Original Message -----
From: "Michael Zapf" <[email-masked]> 
To: [email-masked] 
Sent: Saturday, February 2, 2013 3:51:59 AM 
Subject: [TI994A] Re: RXB problem 

HI Rich, 

Michael

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From: "Ksarul" <[email-masked]>
Date: Sat, 02 Feb 2013 10:51:22 -0500

The Asgard XB III cart used a variant of the OPA cart, as OPA was building
the carts for Asgard (and OPA only delivered a few of them, at that-a
problem that triggered the departure of Chris Bobbitt from the TI world).
Note that the XB code in those carts is from Winfried Winkler-and that it
requires the computer to be running with at least 32K of RAM, as it expects
the Memory Expansion to be present.  He rewrote some of the routines to
eliminate bugs he discovered in TI Extended BASIC and added quite a few
routines of his own.  Rich, he was probably one of the few truly gifted GPL
gurus out there (other than you).

Jim

From: [email-masked] [mailto:[email-masked]] On Behalf Of
[email-masked]
Sent: Saturday, February 02, 2013 6:56 AM
To: [email-masked]
Subject: Re: [TI994A] Re: RXB problem

Also Asgard made a RXB cart I think or someone that worked with Asgard said
they did.

There was also a build your own single GRAM cart project that some people
used to make RXB carts.

 

Rich

  _____  

HI Rich,

To be more specific, my question was whether there were real 8K GROMs (as a
chip, like the TMC0430). I would guess the cartridges you mentioned had an
EPROM on board with some circuits that made the EPROM look like a GROM to
the console, and that way you easily got an 8K space.

Michael