tag:blogger.com,1999:blog-6993165553021868648.post3956326643221673548..comments2024-03-27T05:39:24.505-04:00Comments on Nerdly Pleasures: Turbo Duo - Issues and SolutionsGreat Hierophanthttp://www.blogger.com/profile/04409413307024477304noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-6993165553021868648.post-52526888185849180552016-03-05T12:22:40.204-05:002016-03-05T12:22:40.204-05:00Thanks for the reply!!! :-)
Emulating the CD-Rom ...Thanks for the reply!!! :-)<br /><br />Emulating the CD-Rom is an interesting question. But my question is not about emulating the CD-Rom. My question assumes one is using either a Turbo Duo, or that the CD-Rom add-on is physically present.<br /><br />My question relates more to the relationship between the PCE proper, the system card, and CD drive. Unless my understanding of the relationship is totally wrong, the system doesn't look to the CD-Rom directly. Instead, other than the ADPCM channel, the PCE pretty much ignores the CD-Rom, but only reads from the system card as if it reads any Hu-Card. Instead, the CD interacts with the system card and fills it with the data for the system to then interact with. In other words, as far as just the actual internals of the PCE itself as a stand-alone device is concerned, there's no difference between Lords of Thunder and Legendary Axe.<br /><br />Also, my understanding of the relation between the extra RAM in the Super CD-Rom2 and Arcade CD-Rom2 cards with the system is ---NOT--- one of a RAM boost for the system, but rather as a giant ROM for the system to read......once again.......just like any Hu-Card.....only much bigger.<br /><br />So ---IF---, (and I said "If") I'm right on both of those points, and -IF- a physical disc drive is present, then I'm at a loss to see what the challenge would be in simply putting the CD ISO on the SD card and pointing the Everdrive to it, especially if the system is looking at the Hu for the game, rather than disc drive anyway.<br /><br />So, why wouldn't this work? Even if I'm wrong, and it does look to the disc drive, all someone would have to do, I'd think, is write a disc that simply redirects back to the SD card and we'd be good.<br /><br />Anyway, if this wrong, please help me see why it is and help me understand why we'd need more than just an ISO on an everdrive in a system wth a CD Drive present to play a CD game.<br /><br />Thanks!!! :-)The Long Versionhttps://www.blogger.com/profile/04124696417717624036noreply@blogger.comtag:blogger.com,1999:blog-6993165553021868648.post-9099897118473780142016-03-05T11:48:23.582-05:002016-03-05T11:48:23.582-05:00I am not sure how capable the latest Turbo EverDri...I am not sure how capable the latest Turbo EverDrive (2.4) is, so I do not know whether it would be even possible to try to emulate the CD interface. If it were, I'd be all over it.<br /><br />The CD seems to be something of a simple device, adding 64KB of work RAM, 64KB of sample RAM and the ADPCM chip. The CD System Card adds the BIOS and the Super CD System Card adds the BIOS and 192KB of extra work RAM. <br /><br />Unlike the Turbo EverDrive v1, the Turbo EverDrive v2 has at least 1MB of RAM instead of flash memory, so emulation becomes a little more feasible. I do not know how flexible the RAM addressing is, or whether the EverDrive has the logic blocks available to emulate the ADPCM chip or the streaming CD audio. <br /><br />If you compare the pinouts for HuCard connector and the Expansion Connector, you will find that all or almost all the signals you need for the CD expansion can be found on the HuCard connector : http://www.gamesx.com/misctech/pcebp.phpGreat Hierophanthttps://www.blogger.com/profile/04409413307024477304noreply@blogger.comtag:blogger.com,1999:blog-6993165553021868648.post-56843053016225851692016-03-04T22:39:24.839-05:002016-03-04T22:39:24.839-05:00Hi! Help me to understand why PCE CD Rom ISOs woul...Hi! Help me to understand why PCE CD Rom ISOs wouldn't work on an everdrive:<br /><br />Correct me if I'm wrong, but the way I understand the CD games to work on the PCE is to load their data (in batches) onto the system card (HuCard) and then have the system read from the system card the same way it'd read from, say, Keith Courage. In other words, the system card doesn't point the "system proper" to the disc drive in order for the system to read from the disc directly. Instead, the CD "feeds" the system card, and then the system just interacts with the card like normal.<br /><br />So, the Arcade CD-Rom2 card, then, is not some kind of RAM booster for the system itself, so it can better handle the disc, as this article implies. The system doesn't need extra RAM since unlike the Genesis and SNES (which can only read from RAM) it can read straight from ROM. Therefore, RAM doesn't really matter, at least not in the way it matters for SNES/Genesis, or heck, even for modern PCs (my understanding is that the Neo Geo also works this way). The CD writes to the card, yes, but in terms of how the system "sees" and interacts with the ACDR2 card, it's just a giant ROM. In fact, in terms of "ROMs the system 'sees'", it never even "sees" the disc. It "sees" the card which is in turn, "fed" by the disc. <br /><br />This is also why it's improper to say the ACDR2 "enhances" the standard base PCE hardware, but simply "liberates it", "gives it room to 'breathe', to 'fly'" rather than the strangulation and hobbling of monster hardware that we more commonly see in the teeny tiny, mapperless ROMs of the HuCards (other than SF2CE). So the Garou Densetsu Special ACDR2, for instance, is not running on "boosted" hardware, but on a "boosted" ROM on standard hardware. If that's the case, as I believe it is, then that tells us that we've SERIOUSLY underestimated the raw power of the circa 1987, technically 8-bit hardware, and there is an absolute beast lurking inside "the little engine that could".<br /><br />So, if all of this is true, then I see no reason why a CD Rom game couldn't work from the everdrive SD slot since the system is going to be looking for the game on the HuCard anyway, and not the CD tray. I don't know, maybe you would need to program the "load spots" into the ROM, so it doesn't try to load the whole game at once. But unless you can demonstrate for me that I just have a complete misunderstanding of the relationship between PCE and PCE CD (which I am open to seeing) I am having a hard time seeing the problem here. <br /><br />If the everdrive doesn't have the memory capacity of an ACDR2, then I can see how ACDR2 games wouldn't work. And I also acknowledge that just like you'd need an actual Supergrafx with its second GPU in order to play Supergrafx games on the drive, you'd still need the actual CD add-on (or TurboDuo) present since some games use large ADPCM sound files (like voice clips during battle sequences or whatever) and those are all handled by an extra sound channel in the CD system itself (the ONLY thing CD adds to the hardware proper!) <br /><br />So no, you and an everdrive, and a plain Jane TG16 are not gonna be playing Double Dragon 2. But if all the requisite hardware is present and accounted for, then I see NO REASON why a CD-Rom2 ROM or even a SuperCD-Rom2 would not work on an everdrive.<br /><br />So help me out here! What am I missing? Why don't CD Rom games work if, assuming my hardware analysis is correct, they should work beautifully?<br /><br />Cheers!<br />The Long Versionhttps://www.blogger.com/profile/04124696417717624036noreply@blogger.com