Turbo Everdrive 2.4

[Bonknuts]

Hey elmer, or anyone else familiar with TED 2.4 (MooZ ?), can you run by the ram mode for me again?

 Can SF2 be run in all ram mode? Is all 4megabytes of ram accessible in some other mapper mode?

 The reason I ask, and this came up in another thread, is that it would be cool to convert a few stages of PCE CD games to run on hucard. Ram mode would definitely allow for that. Gate of Thunder and Force Gear are the two that I had in mind.

[elmer]

Hey elmer, or anyone else familiar with TED 2.4 (MooZ ?), can you run by the ram mode for me again?

Can SF2 be run in all ram mode? Is all 4megabytes of ram accessible in some other mapper mode?

Yes.

The reason I ask, and this came up in another thread, is that it would be cool to convert a few stages of PCE CD games to run on hucard. Ram mode would definitely allow for that. Gate of Thunder and Force Gear are the two that I had in mind.

All the details are here (sadly, not stickied, yet) ...

http://www.pcenginefx.com/forums/index.php?topic=20120.msg436168#msg436168

Look at the TED_REG_MAP bit settings. 

[elmer]

Hey elmer, or anyone else familiar with TED 2.4 (MooZ ?), can you run by the ram mode for me again?

Can SF2 be run in all ram mode? Is all 4megabytes of ram accessible in some other mapper mode?

OK, trying to be a bit more explicit ...

The TED2 has 8 banks of 512KB.

Bank 4 is always mapped into the low 512KB of HuCard address space.

Any of the the 8 banks can be mapped into the top 512KB of HuCard address space.

"Yes", you can leave the system in RAM mode instead of ROM mode when you enable/use the SF2 mapper at bytes $1FF0-$1FF3, but then you're going to overwrite those bytes when you change the bank.

You only have access to 2.5MB if you use the SF2 mapper.

To access the whole 4MB you've got to write to the TED2's mapping register directly.

Whenever you enable/use the RAM mode, then unlocking and writing the TED2's registers is going to overwrite/corrupt RAM locations $00:$0005, $00:$0006, $00:$0007, and $00:$000A.

It's a fairly good idea to not actually use the bottom 12 or 16 bytes of bank $00.

[Bonknuts]

This should be a sticky.

To access the whole 4MB you've got to write to the TED2's mapping register directly.

Whenever you enable/use the RAM mode, then unlocking and writing the TED2's registers is going to overwrite/corrupt RAM locations $00:$0005, $00:$0006, $00:$0007, and $00:$000A.

It's a fairly good idea to not actually use the bottom 12 or 16 bytes of bank $00.

 Ohh, that's good to know. For the CD2HUey, I'll need to relocate the bios function entry points there (mostly CDREAD and CDBOOT).

 Kinda offtopic, but I was looking into the bios function list to see if there was any free space, and I came across some functions that aren't covered in the CD manual (the last 5 or so). What is MA_CBASIS???

 EDIT: Have you tested to see if TED 2.x loads 4megabyte rom data into the all 8 banks? Or does it stop at the first 5 (ala SF2)?

[elmer]

This should be a sticky.

Or you could just modify your 1st post in the "Graphic, Sound, & Coding Tips / Tricks / Effects / Etc." thread to be a "links" post to other threads with interesting and useful information. 

Whenever you enable/use the RAM mode, then unlocking and writing the TED2's registers is going to overwrite/corrupt RAM locations $00:$0005, $00:$0006, $00:$0007, and $00:$000A.

It's a fairly good idea to not actually use the bottom 12 or 16 bytes of bank $00.

 Ohh, that's good to know. For the CD2HUey, I'll need to relocate the bios function entry points there (mostly CDREAD and CDBOOT).

Yep, that's the problem that I had with the TED2 System Card hack.

I ended up keeping copies of the first and last 16 bytes of bank $00 and then copying them back into place after they'd been corrupted by having to write to the TED2 registers while bank $00 was in RAM mode.

You can actually use the SF2 mapper to access the top 2MB of RAM space ... you've just got to use the TED2's registers to decide which 2MB region you want the SF2 mapping to use, and then understand that the bottom 512KB of HuCard space is always the TED2's bank 4.

Have you tested to see if TED 2.x loads 4megabyte rom data into the all 8 banks? Or does it stop at the first 5 (ala SF2)?

I've not tested it, but I imagine that it only loads 2.5MB maximum.

Krikzz doesn't seem to bother too much with thoughts of theoretical concerns of what us homebrew folks might do in the future with the extra memory.

BTW, Krikzz is using some of that extra 1.5MB of space for the TED2's OS.

[Necromancer]

They're both stickied now.  I don't know if it'd make sense or not (this stuff is way over my head), but I can merge 'em if you want.

[elmer]

They're both stickied now.  I don't know if it'd make sense or not (this stuff is way over my head), but I can merge 'em if you want.

Thanks! 

From my POV, I don't think that we need this thread to be stickied, just the "TED2 Programming Notes" thread.

That's the one with the core information, and I'll be updating that thread when I finally get the time to get back to figuring out how to access the SD Card.

Best to check with Bonknuts, though.

[Bonknuts]

One thread is fine.

[MooZ]

I only have a v1.
I can't imagine how much unrolled self modifying code I can put into 512KB of RAM...

[elmer]

I only have a v1.
I can't imagine how much unrolled self modifying code I can put into 512KB of RAM...

I really can't recommend the TED v2 highly enough, especially with the USB link because you're a programmer.

Having 1MB/2.5MB/4MB of RAM (depending upon how you want to set it up) is a really, really nice. 

The only reason to limit stuff to 512KB would be in order to run on a semi-cheap-to-make 512KB ROM + 512KB RAM HuCard that nobody has made yet.

Even then ... I'd honestly prefer a simpler and even cheaper 1MB RAM card (using the Duo's built-in BIOS), or just paying the little bit extra for the TED v2.

[TheOldMan]

The only reason to limit stuff to 512KB would be in order to run on a semi-cheap-to-make 512KB ROM + 512KB RAM HuCard that nobody has made yet.

I thought you were worried about fracturing the market for flash cards. Worried that games would have to have code to deal with various mappings, etc.

Did you want one? It works like a standard HuCard, except banks $40-$67 are available. They only have a memory test on them, so you would need an eeprom programmer and adapter to re-program it. I'm working on pulling together bios and some extra stuff, but there's no hurry, since there is no demand.

I've been thinking about what tom said, though. I may do one with the RAM in the $8000 area, just to see if I can get a 8Mb rom and 512k Ram to work.

[elmer]

The only reason to limit stuff to 512KB would be in order to run on a semi-cheap-to-make 512KB ROM + 512KB RAM HuCard that nobody has made yet.

I thought you were worried about fracturing the market for flash cards. Worried that games would have to have code to deal with various mappings, etc.

Definitely ... when it comes to translations, which was the primary driver for this whole "I need more memory" discussion that we've been having over the last year.

Limiting things to 512KB certainly makes the most sense for translations that just need a little extra space and want to work on pretty-much-any expanded-memory card that's been released, or is ever likely to be released.

When it comes to homebrew, then I think that things are a bit more open to each individual developer's desires.

Did you want one? It works like a standard HuCard, except banks $40-$67 are available. They only have a memory test on them, so you would need an eeprom programmer and adapter to re-program it.

Thanks for the offer, I really appreciate it, but I'm afraid that I really can't quite figure out what I'd actually use one for.

I'm working on pulling together bios and some extra stuff, but there's no hurry, since there is no demand.

This is my problem with a ROM/RAM card when we talk about it as a new System Card "standard".

It's software that sells things, not the hardware.

I already have 2 alternatives for doing a CD game that gives me lots of memory ... the Arcade Card, or the TED v2.

I have difficulty imagining a CD project that I'd be interested in, where the additional cost of a new System Card with only 512KB on it would make any sense.

The TED v2 makes sense for folks to buy ... it does a lot of stuff.

The Arcade Card is something that a lot of folks already have.

I'm just having trouble seeing where a 512KB/512KB System Card fits in, or would actually be cheap enough to sell to folks.

*************

Conversely, looking at things from a HuCard perspective, where I don't have a large CD of stuff to load, then I really don't need that much RAM. I wouldn't know what to do with it!

If I'm shipping something on ROM, then I want as much space as possible for data, and don't really need lots of RAM.

Something larger than the 8KB in the base PCE console would be nice, sure, but 64KB or 128KB would be plenty if I just need space to decompress stuff from the HuCard.

At that point, I'd probably be tempted to rely on using the 64KB of memory in the CD system and leave the 1MB of HuCard space entirely for ROM.

It would require folks to have a CD system, but that's not exactly a show-stopper these days.

OTOH, putting a small amount of RAM in upper memory isn't that difficult (except for fitting it on the HuCard) if you don't mind charging folks for it.

Then again, these are just my thoughts and perspectives based upon the kind of game projects that would interest me to do.

Perhaps other folks have a different perspective.

I've been thinking about what tom said, though. I may do one with the RAM in the $8000 area, just to see if I can get a 8Mb rom and 512k Ram to work.

Do you mean the bank $80 area???

If so, then you definitely can't use that, because you'd conflict with the 64KB of memory in the CD interface.

But banks $a0-$df are free AFAIK if you want to put some RAM in the upper area.

[TheOldMan]

Thanks for the offer, I really appreciate it, but I'm afraid that I really can't quite figure out what I'd actually use one for.

Funny, that's kind of my problem.too. I don't think i've ever used all of even the stock 8K of ram.

This is my problem with a ROM/RAM card when we talk about it as a new System Card "standard".

I don't think of it as a new 'standard'. I doubt that many would be produced.
Where I do think it would be useful is for an in-expensive debugging tool.

At that point, I'd probably be tempted to rely on using the 64KB of memory in the CD system and leave the 1MB of HuCard space entirely for ROM.

I can see that. But then you are limited to CD systems (which isn't a big deal to most of us).

I'm just having trouble seeing where a 512KB/512KB System Card fits in, or would actually be cheap enough to sell to folks.

Ok. But it's been fun to play with, And see how cheaply it could be done. (Its about $20 in parts)

Do you mean the bank $80 area???

Actually, I meant the $80000 area, as in upper half of the address space. I still think I could fit 512k ram up there cheaply. And no, not at the $80 bank. Maybe the  $A0-$D0 bank range. Right in the middle. (Physical addresses $a0000-$Cffff, I think)

I'll go back to working on the video converter now. With toms quick cd read routines and 512K Ram for bufferring, I might just get sewer-shark working yet

[Bonknuts]

I already have 2 alternatives for doing a CD game that gives me lots of memory ... the Arcade Card, or the TED v2.

 I like the arcade card, but the failure rate on those things makes me a bit more reserved about using it. I've already had one fail (never had a hucard rom fail). I know of five other people/instances were the cards were bad. I opted for the Duo card replacement, simply because of less hardware in the case that something might go out, but there's still a lot of hardware on that card as well. It's be really nice if the next TED, assuming there is one, emulates the AC regs.

Conversely, looking at things from a HuCard perspective, where I don't have a large CD of stuff to load, then I really don't need that much RAM. I wouldn't know what to do with it!

I do! Copy over graphics into a buffer for levels.. as embedded opcodes for super fast VRAM updating.

[Bonknuts]

I'll go back to working on the video converter now. With toms quick cd read routines and 512K Ram for bufferring, I might just get sewer-shark working yet

It'd probably be easier to isolate/rip the huvideo player for that kind of thing.. which I don't have :/