Neo Geo games to Jaguar? Would be possible?

[laymanpigeon]

Some of you people want to be taken seriously only to resort to insults and when I do an eye for an eye then you label me a troll, if you want to correct someone, debate and provide counter arguments while being taken seriously then do not resort to insults and accusations that are slanderous. Now that includes you DEATH and if this is a problem with many people then why do not you write Frequently Asked Questions? If you were that smart then you and people like you would have done so yet here we are when none of you did that despite this forum being over 20 years old I think.

 

6 megabytes/48 Megabits limit makes sense when only consideration were 2D games and flat shaded or phong shaded polygons, yet that was equal to maximum for Super Nintendo and a bit larger than 40 megabits for Sega Genesis. Meanwhile Neo Geo had limit of 330 megabits initially then bank switching was implemented thus raised maximum to 716 megabits in order to store so huge sprites with many frames to achieve smooth animation. CD-ROM Drive on Jaguar would be needed for Neo Geo games as to not compromise content of with cutbacks yet unsure if DRAM cartridge could work on Jaguar since it would be needed to store all those graphic asset. Unlike on Saturn with CD-ROM Drive and cartridge port being separate. Well it would have been a different story if Atari survived long enough to release Jaguar II. 48 megabits / 6 megabytes cartridge was perhaps one of turn off's for developers since Jaguar was supposed to be next generation system yet had cartridges that did not store more data than Super Nintendo's. At least Super Burnout demonstrated Jaguar being next generation in terms of 2D graphics with smooth sprite scaling that would give Sega Saturn run for its money.

 

[DEATH]

Oh, I found in my personal archives the datasheets of a FPM DRAM with a Fast Page Mode cycle time of 25ns (and even 23ns) and an access time of 45ns (or less). Which means that IF (my aunt had any, we'd call her my uncle) the Jaguar was able to maintain a page mode cycle of 1 clock cycle at 40Mhz it could have a bandwidth of 320MB/s, woohoo. And a refresh time of 2 cycles. UNNNbelievable! I feel that someone here is not going to sleep at night.
Well, no luck these datasheets date from 1999. Tough luck huh. Not to mention that the Jaguar, even at 26.6Mhz and 2 cycles time of Fast Page mode, is not even capable of maintaining this speed for more than 2 or 3 cycles of FPM reading, there is always 1 cycle that gets lost in the middle of the race... Too bad huh.

[laymanpigeon]

Availability of SDRAM

March 1993

Removing 68HC000 would offset increased cost of implementing SDRAM over FPM DRAM.

68000 and FPM would no longer be limiting factor for frequency of both Tom and Jerry.

DRAM Prices in 1993

June 1993

[phoenixdownita]

Someone should stop rewriting history.

 

Even in the very competitive PC market Intel would support EDO only starting in 1995.

https://www.pctechguide.com/chipsets/intels-triton-chipsets-explained-their-history-architecture-and-development
 

 

[+CyranoJ]

Well, you got a like from philipj, once JagChris gives you a kiss you will have a complete seal of approval from the two most eminent scholars of the forum.

[DEATH]

13 minutes ago, phoenixdownita said:

Someone should stop rewriting history.

 

Even in the very competitive PC market Intel would support EDO only starting in 1995.

https://www.pctechguide.com/chipsets/intels-triton-chipsets-explained-their-history-architecture-and-development
 

 

He just posts stuff he found on the Internet while doing research without understanding the meaning. He doesn't realize that the capacities available for the most recent and efficient RAM were insufficient and overpriced, he also doesn't understand that in any case the design of the Jaguar as it is did not even allow to reach the maximum speed of the technology used, he doesn't understand the principle of mass production costs, he doesn't even see that the availability date of what he's talking about already exceeds the design date and even the release date of the Jaguar, he doesn't understand the principle of inflation and that for example $15 in 1993 is the equivalent of more than $32 today, etc. etc.

[phoenixdownita]

43 minutes ago, DEATH said:

He just posts stuff he found on the Internet while doing research without understanding the meaning. He doesn't realize that the capacities available for the most recent and efficient RAM were insufficient and overpriced, he also doesn't understand that in any case the design of the Jaguar as it is did not even allow to reach the maximum speed of the technology used, he doesn't understand the principle of mass production costs, he doesn't even see that the availability date of what he's talking about already exceeds the design date and even the release date of the Jaguar, he doesn't understand the principle of inflation and that for example $15 in 1993 is the equivalent of more than $32 today, etc. etc.

Yeah and the constant harping on price of the 68hc000 that even Sega adopted in 93 for their late md1, the cost reduced md2 and the cd1 and cost reduced cd2, is so annoying.
I am 100% sure by the time the design was finalized the 68k was cheaper than the 020 (EC too) and it stayed so throughout for Atari and the other companies using it.

I would not be surprised Motorola was moving to depletion process fully and stopped nmos production, likely Atari, Sega and others got the HC for the same lower price as negotiated or as they had before if not even cheaper.

 

 

Edit: completely forgot HMOS power is largely independent from frequency vs CMOS https://en.m.wikipedia.org/wiki/Motorola_68000#CMOS_versions

Also in the same section “Motorola ceased HMOS production of the 68k in ‘96” … so both variants were available and afaik swappable.

Edited September 13 by phoenixdownita

[42bs]

Ok, what did we find out in this long thread?
 

1) Jaguar is a 3D console perfect for 2D games and weak for 3D.

 

2) If Atari/Flare had enough money and would not care for production cost it would have been _the_ killer console for the 90s running at 40MHz on a 68EC030.

 

3) Some people _start_ insulting others when they run out of arguments and then complain for the echo.

 

4) No one wants to port Neo Geo games to the Jaguar, possible or not.

 

Missed anything?

 

Open questions:

 

1) Why did Atari choose 26.xxxx MHz over 32MHz when the 68000 (or HC) is specified for 16MHz?

  => Possible answer: Perfect frequency for NTSC/PAL TV sets.

 

2) Why does Jerry only have a 16bit bus?

 

3) Why do we still love this machine despite it is so crippled.

 

 

[phoenixdownita]

27 minutes ago, 42bs said:

.....

 

Missed anything?

 

Numberwanging is not a recognized form of communication.

[roots.genoa]

3 hours ago, 42bs said:

3) Why do we still love this machine despite it is so crippled.

I think this is precisely because it is crippled that (some) people love it today. It's clearly the ultimate underdog of video games. It was Atari's last console (like the revered Dreamcast), and was a huge failure commercially, even compared to notoriously failed systems like the Virtual Boy.

 

Having writing about homebrew games for almost 15 years, it's obvious that some systems get a lot more love today than they used to back then (Jaguar, 7800, Virtual Boy, ColecoVision...). Of course popular systems like Atari 2600, NES, and Genesis get a lot of new games as well, but mostly because they usually benefit from better, more accessible tools to develop for. However, it has already been discussed it's often easier for a single programmer to make a port rather than an original game, since he doesn't have to come up with graphics and gameplay, so it's easier to port classics on systems that didn't get them back then. It's pretty obvious on the ColecoVision and the 7800 especially, that got more "new" games (mostly ports) in recent years than what they got at the time.

 

The homebrew scene has always been (partly) about repairing injustice, and the Jaguar is probably one of the systems that require the most "repairing". 😅

[DEATH]

6 hours ago, 42bs said:

 

 

4) No one wants to port Neo Geo games to the Jaguar, possible or not.

 

Missed anything?

 

Open questions:

 

1) Why did Atari choose 26.xxxx MHz over 32MHz when the 68000 (or HC) is specified for 16MHz?

  => Possible answer: Perfect frequency for NTSC/PAL TV sets.

 

2) Why does Jerry only have a 16bit bus?

 

3) Why do we still love this machine despite it is so crippled.

 

 

"4) No one wants to port Neo Geo games to the Jaguar, possible or not." : Yes, yes, why not, especially at the time. But today indeed... it would just be a matter of saying that it is possible... And it would still be fun, right?

"

1) Why did Atari choose 26.xxxx MHz over 32MHz when the 68000 (or HC) is specified for 16MHz?

  => Possible answer: Perfect frequency for NTSC/PAL TV sets." 
as I said: for a question of cost. More precisely of cost/performance ratio. This frequency was chosen because it allowed it to be used to synchronize the video signal and to have a reasonable performance of the console with only one clock. If they had wanted to increase the frequency of the system there were several solutions but which increased the cost whatever the solution chosen or were even impossible. For example just double the frequency of the master clock, very bad solution. The whole design of the motherboard to review, impossibility of running anything in the system at these frequencies without adding a multitude of components, etc. Put 2 separate clocks (the Jaguar is designed for), but again, additional cost on all sides (but it is the simplest solution), with in particular overheating problems to solve, propagation time problems in TOM and Jerry (they are already so full of Bugs ...). That said, it is feasible SCPCB does it.

"2) Why does Jerry only have a 16bit bus?" still for cost reasons certainly. Jerry uses the same CPU interface as the 68000. All the logic is therefore based on the same operation. The 68000 is on 16bit, so Jerry must be too... The Jaguar is also designed to work with a 32bit processor (but to what extent...) and in this case Jerry would also be in 32bit, but... that's without counting on Jerry's bugs, it does not work correctly with a 32bit BUS and that external logic must be added to correct it...

[phoenixdownita]

6 hours ago, DEATH said:

…
"2) Why does Jerry only have a 16bit bus?" still for cost reasons certainly. Jerry uses the same CPU interface as the 68000. All the logic is therefore based on the same operation. The 68000 is on 16bit, so Jerry must be too... The Jaguar is also designed to work with a 32bit processor (but to what extent...) and in this case Jerry would also be in 32bit, but... that's without counting on Jerry's bugs, it does not work correctly with a 32bit BUS and that external logic must be added to correct it...

Do you have any pointers to docs about the known issues + required glue logic to run the chipset with a 32 bit cpu?

I would really enjoy reading it.

Edited Friday at 05:58 PM by phoenixdownita

[Austin]

14 hours ago, 42bs said:

3) Why do we still love this machine despite it is so crippled.

Because some of its library is actually fun to play. Which I think most seem to forget about these days.

[DEATH]

2 hours ago, phoenixdownita said:

Do you have any pointers to docs about the known issues + required glue logic to run the chipset with a 32 bit cpu?

I would really enjoy reading it.

You can find the information in the various official Jaguar documentations. The details of the bugs are mentioned there but very little on how to work around them (because that is not the purpose of the documentation and it is about electronic workarounds). The CoJag must use external chips to work around these bugs.

[phoenixdownita]

18 hours ago, DEATH said:

You can find the information in the various official Jaguar documentations. The details of the bugs are mentioned there but very little on how to work around them (because that is not the purpose of the documentation and it is about electronic workarounds). The CoJag must use external chips to work around these bugs.

I read those errata at the end of https://www.hillsoftware.com/files/atari/jaguar/jag_v8.pdf but I was hoping in some doc describing how the cojag “worked” around them or fixed them.

 

Thank you for your insights though, I thought the support for a 32bit cpu was more developed/less buggy as the aforementioned doc hints at at the very beginning.

[DEATH]

2 hours ago, phoenixdownita said:

I read those errata at the end of https://www.hillsoftware.com/files/atari/jaguar/jag_v8.pdf but I was hoping in some doc describing how the cojag “worked” around them or fixed them.

 

Thank you for your insights though, I thought the support for a 32bit cpu was more developed/less buggy as the aforementioned doc hints at at the very beginning.

To be more precise and "honest", Jerry's 2 known bugs concerning 32bit operations do not really prevent it from working without additional external chips. Besides, from what I remember, one of these bugs cannot be corrected anyway. In fact Jerry can work in "32bit mode" but without correction it will then be necessary to use its external BUS strictly in 16bit (absolutely no operation on the data bus must be performed in long words). Another thing, it is possible that these bugs are not mentioned in all the documentation because it does not concern the Jaguar but only Jerry.

[agradeneu]

On 9/13/2024 at 6:06 AM, 42bs said:

 

 

3) Why do we still love this machine despite it is so crippled.

 

 

I dont think "crippled" was an appropriate wording for drawbacks of the hardware.

 

In the end, Atari thought that performance for price/Cost was better than the competition. 

 

Even with improvements, i dont think we could expect huge performance boost in both 2D or 3D, but much higher price for the consumer.