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Expanded Basic 3 - Resources


dhe

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2 hours ago, dhe said:

YES! but, fortunately, for us, your this really smart guy who can get us a one of one dump and tell us how the bank switching REALLY works.

But hey, no pressure! ?

 

I think the issue is not the dump, but the architecture of the cartridge itself and how the two EPROMS are utilized. Which means someone with knowledge of such things would need to disassemble the cartridge.

 

 

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We have the dumps and we have photographs of the PCB, but there are four PALs that we don't know the operation of. At any rate, taking your cart apart won't teach us any more than we have. We can either reverse engineer the code to figure out how they work, or bug Gary to dump as much as he remembers. ;)

 

It's not at the top of my personal priority list, but it does look like a pretty impressive cart. ;)

 

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5 hours ago, adamantyr said:

Good to know, thanks Tursi!

 

I just tested my cart and it works with TIPI and SAMS and it worked fine. Even managed to load my CRPG through both XP3's auto-loader and the provided E/A module.

What does the SIZE command report?

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9 hours ago, adamantyr said:

If someone has a dump utility already written to do the work, great! I'll be happy to run it.

I have written a whole collection of dump tools; you can certainly get one - but I still have to adapt it to the banking scheme. Can I send you a file in TIFILES format or a DSK?

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11 hours ago, dhe said:
Comparing the two screens, yours is two years more mature, then the dump everyone else has. 1991 vs 1993, so it would definitely be a plus if you could dump it.

 

I don't know about what versions are all floating around out there, but @Schmitzi posted an archive that purports to contain this same version back in April 2017. 

 

 

In the archive are four dumps as well as photos of the board.

 

I haven't dug deep into the contents of the dumps, although there are a lot of duplicate files in the XB3_Winkler_DUMP folder. But the one labelled XB3_Winkler_Eproms seems to contain the dumps of the two 128KB EPROMs, and they look reasonably legit. The photos included say this is the same version that Adamantyr has.

Edited by Tursi
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I also had a look at the archive, and I trust the dumps of the two 128K EPROMs.

 

Still, I would like to make sure how these contents are mapped into memory. The DUMP folder has a lot of files that were been dumped by one of my tools, but intended for MBX cartridges, so I don't really feel confident that these are helpful. @adamantyr could run a test program that writes to 600x and we'll see what contents appear in ROM and GROM space.

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Well, it's not a complete analysis, but MOST of the Popcart EPROMs "just work" when mapped into Classic99 correctly.

 

The "Right" EPROM is two GROM bases, the entire memory space from >0000 to >FFFF is replaced at base >9800 and >9804. (Based on Gary's comments in the other thread, up to 8 bases are supported by the PALs, but here there are only two).

 

The "Left" EPROM is ROM data. It seems to contain 4 pages of 8K ROM paged with our usual write-to-ROM tactic, non-inverted order. Only three of the four pages are actually used, accessed with writes to >6000, >6002, and >6004. I don't know whether the PALs echo the rest of the space like XB does. The rest of the EPROM seems to contain some code, and a simulated disk image. There are certainly FDRs and the data is laid out in 256 byte blocks, there are even the recognizable E5 bytes of empty sectors, but I didn't see the index sector. Might have missed it. The GROMs contain a DSR called "CART" so I suspect this is the data for that.

 

It was not clear to me how to get these working, yet. The software frequently hits 9 CRU addresses - from 0x580 through 0x587 are always written in sequence. I couldn't get a clear pattern, except that it appears that 0x586 is related to turning the RAM chip on and off that Gary mentioned. (The Popcart in question did not ship with RAM, but there's an option for it in the XB3 menu, so I could toggle it at will. However, Classic99 had ROM there, and it appeared to test whether there was ROM or RAM before deciding what to send, so I only got one result). 

 

It also writes to CRU 0x780 at startup and before DSR access in XB3, but I only ever saw it set 0.

 

To get that far, I split the right EPROM into two 64K files, and then loaded it all with this Classic99.ini. Everything except the XB3 menu (and the software underneath it) appears to work.

 

[usercart1]
name=Test Popcart (menu not working)
; loading it all appears to work, and lets the XB3 menu start (but it is still corrupt)
rom0=8|0000|20000|D:\classic99\MODS\XB3_Asgard-Winkler-Birkenau-2017\XB3_Winkler_Eproms\left_AM27C010.bin
; GROM is loaded into two bases
rom1=G|0000|10000|D:\classic99\MODS\XB3_Asgard-Winkler-Birkenau-2017\XB3_Winkler_Eproms\right_xaa
rom2=G1|0000|10000|D:\classic99\MODS\XB3_Asgard-Winkler-Birkenau-2017\XB3_Winkler_Eproms\right_xab

This readme covers my findings so far...

 

readme.txt

 

Edited by Tursi
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7 minutes ago, arcadeshopper said:

It should but it only seems to detect the original smaller AMS not Sams

Sent from my LM-V600 using Tapatalk
 

I'm sure someone can hack it to fix the detection, unless the hardware is working differently [edit: in a non-backwards-compatible way]?

Edited by Asmusr
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Based on the TI Tech Pages (which admit they don't have the schematics to look at), it was substantially different enough to not be a simple change that could be hacked in.

 

In particular:

  • It could only be 128K or 512K (probably because it had only one memory chip)
  • The area >2000-3FFF could not be paged (?)
  • The most significant bit was permanently set to one, so page 0 would in fact be page 128 (??)

That's significant enough that wiring up the SAMS card would require a re-write of anything do to with expanded memory. And given we don't have source code, not happening.

 

Just use RXB instead. :D

 

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Academically, it would be interesting if Classic99 or MAME supported OAMS (Original AMS Memory System) - so if you did run in to a program that says - supports AMS memory, you could run it in emulation mode to determine, if it only supports AMS (Classic ? ).

I'd bet the number of original 128K AMS cards, is probably not that much greater than real XB3 modules. I know, at about the time period those came out, there had been enough shipping delays, that a fair number of people where only willing to purchase at a fair (if the product was available to take home) or from a dealer that had an item in stock.

But thanks Adam, I wasn't only vaguely aware there was a difference between AMS and SAMS, but your summary has helped a lot!

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