5 ms·

The Sega System E: The Master System Supergrafx

92 points by zdw 4y ago

mikepavone 4y ago
As it turns out, the video overlay feature described in the article also survived in the Genesis/Mega Drive VDP which is derived from the SMS one, but drops the TMS9918A modes. This feature was used in the System 18 arcade board which combines System 16B video hardware with the Gen/MD VDP. It may have also been used in the LaserActive for combining VDP output with LaserDisc video, but I'm less sure there.
- glhaynes 4y ago
  Kinda reminds me of how the Genesis/Mega Drive’s audio incorporated both the new Yamaha FM synth chip and the Master System’s TI programmable sound generator. Covered backwards compatibility but they also could both be used at the same time and mixed. See the “Audio” section here: https://www.copetti.org/writings/consoles/mega-drive-genesis/ https://www.copetti.org/writings/consoles/mega-drive-genesis...
  - djmips 4y ago
    It's not quite the same thing because the Yamaha FM synth chip is a completely new architecture whereas you could say the Mega Drive graphics are more evolved from the SMS / 9918.
- msk-lywenn 4y ago
  Any idea why they didn't use the feature for the 32X ?
  - toast0 4y ago
    Without knowing the details, I'd guess that in order to link the VDP, you'd need to connect via pins that weren't available on the cartridge slot or the expansion slot. It would have to have been planned (or at least considered) during the design of the genesis/megadrive.
  - mikepavone 4y ago
    It's a bit unclear. Between the cartridge port and the A/V connector you should have access to the signals you need to make it work. If I had to guess, the fact that CSYNC reverses direction is kind of awkward for a device that needs to act as a transparent pass-through for non-32X games.
- fredoralive 4y ago
  Are you sure, I can’t seem to see any inputs on the pin outs given at for example at https://md.railgun.works/index.php?title=VDP#Pinout https://md.railgun.works/index.php?title=VDP#Pinout - there’s definitely an ROUT, GOUT and BOUT, but no RIN etc. They could be using the digital pixel bus that the Model C uses to get more colours from the VDP than a Megadrive, and merging that with other data streams from other video chips ala Supergrafx??? Its interesting though that the Megadrive VDP has features like the pixel bus and extra VRAM support to let them use the chip in arcade machines without some of the limitations the home system has because of cost.
  - mikepavone 4y ago
    To be precise, the SMS and Gen/MD VDP versions of this feature work slightly differently from the TMS9918A version of it. The CSYNC output pin becomes an input and is used to synchronize video generation, but you need external hardware to mix the video together. This is also true of TMS9918A variants that output separate luminance and color difference signals like the TMS9928A. Generally this mixing is done with the analog video signals (RGB in the case of the SMS and Gen/MD, luminance/color difference for the TMS9928A), but you could use the digital pixel bus. The downside to that is you need external CRAM and video DAC. edit: Technically, the TMS9928A doesn't have the CSYNC as input part and just relies on the two VDPs running in lockstep.
csdvrx 4y ago
https://nicole.express/2020/super-ultra-mega-tera-grafx.html https://nicole.express/2020/super-ultra-mega-tera-grafx.html > That makes a grand total of six exclusives, plus Darius Plus and Darius Alpha, a limited-release special edition of Darius Plus that seems to exist primarily to make it hard to collect a complete set of SuperGrafx-compatible games > It’s not surprising that the SuperGrafx wasn’t very successful. With 6 games total? Yes.
- mysterydip 4y ago
  Has "rush to market" ever ended up successful? I can think of several instances where it wasn't (trying to meet Christmas deadline, or beat a competitor to market by x weeks).
  - Cyberdog 4y ago
    After the Wii U floundered, Nintendo released the Switch mid-generation, which is generally not the right time to release a new console ID tire assuming for success. But we saw how it turned out.
  - djmips 4y ago
    Indeed some rushes to market have ended up successful - Soul of a New Machine by Tracy Kidder documents in detail one such case and there are many more. It's easy to dwell on the failures however. I think it's fair to say that many products that are on the market are rushed to market - some very successfully.
  - vikingerik 4y ago
    Javascript was famously rushed out in ten days, and ended up eating the world.
chrisgd 4y ago
I received a turbografx16 handheld around 1991 for Xmas. It had a tv tuner and I had two games. I loved it but the battery life was so short I barely ever used it. To this day, I wish I had more patience and interest
pbj1968 4y ago
I always greatly enjoy the posts on this blog. Gotten me through some very slow days.

92 points by zdw 4y ago

As it turns out, the video overlay feature described in the article also survived in the Genesis/Mega Drive VDP which is derived from the SMS one, but drops the TMS9918A modes. This feature was used in the System 18 arcade board which combines System 16B video hardware with the Gen/MD VDP. It may have also been used in the LaserActive for combining VDP output with LaserDisc video, but I'm less sure there.

glhaynes 4y ago
Kinda reminds me of how the Genesis/Mega Drive’s audio incorporated both the new Yamaha FM synth chip and the Master System’s TI programmable sound generator. Covered backwards compatibility but they also could both be used at the same time and mixed. See the “Audio” section here: https://www.copetti.org/writings/consoles/mega-drive-genesis/ https://www.copetti.org/writings/consoles/mega-drive-genesis...
- djmips 4y ago
  It's not quite the same thing because the Yamaha FM synth chip is a completely new architecture whereas you could say the Mega Drive graphics are more evolved from the SMS / 9918.
msk-lywenn 4y ago
Any idea why they didn't use the feature for the 32X ?
- toast0 4y ago
  Without knowing the details, I'd guess that in order to link the VDP, you'd need to connect via pins that weren't available on the cartridge slot or the expansion slot. It would have to have been planned (or at least considered) during the design of the genesis/megadrive.
- mikepavone 4y ago
  It's a bit unclear. Between the cartridge port and the A/V connector you should have access to the signals you need to make it work. If I had to guess, the fact that CSYNC reverses direction is kind of awkward for a device that needs to act as a transparent pass-through for non-32X games.
fredoralive 4y ago
Are you sure, I can’t seem to see any inputs on the pin outs given at for example at https://md.railgun.works/index.php?title=VDP#Pinout https://md.railgun.works/index.php?title=VDP#Pinout - there’s definitely an ROUT, GOUT and BOUT, but no RIN etc. They could be using the digital pixel bus that the Model C uses to get more colours from the VDP than a Megadrive, and merging that with other data streams from other video chips ala Supergrafx??? Its interesting though that the Megadrive VDP has features like the pixel bus and extra VRAM support to let them use the chip in arcade machines without some of the limitations the home system has because of cost.
- mikepavone 4y ago
  To be precise, the SMS and Gen/MD VDP versions of this feature work slightly differently from the TMS9918A version of it. The CSYNC output pin becomes an input and is used to synchronize video generation, but you need external hardware to mix the video together. This is also true of TMS9918A variants that output separate luminance and color difference signals like the TMS9928A. Generally this mixing is done with the analog video signals (RGB in the case of the SMS and Gen/MD, luminance/color difference for the TMS9928A), but you could use the digital pixel bus. The downside to that is you need external CRAM and video DAC. edit: Technically, the TMS9928A doesn't have the CSYNC as input part and just relies on the two VDPs running in lockstep.

csdvrx 4y ago

https://nicole.express/2020/super-ultra-mega-tera-grafx.html https://nicole.express/2020/super-ultra-mega-tera-grafx.html > That makes a grand total of six exclusives, plus Darius Plus and Darius Alpha, a limited-release special edition of Darius Plus that seems to exist primarily to make it hard to collect a complete set of SuperGrafx-compatible games > It’s not surprising that the SuperGrafx wasn’t very successful. With 6 games total? Yes.

mysterydip 4y ago
Has "rush to market" ever ended up successful? I can think of several instances where it wasn't (trying to meet Christmas deadline, or beat a competitor to market by x weeks).
- Cyberdog 4y ago
  After the Wii U floundered, Nintendo released the Switch mid-generation, which is generally not the right time to release a new console ID tire assuming for success. But we saw how it turned out.
- djmips 4y ago
  Indeed some rushes to market have ended up successful - Soul of a New Machine by Tracy Kidder documents in detail one such case and there are many more. It's easy to dwell on the failures however. I think it's fair to say that many products that are on the market are rushed to market - some very successfully.
- vikingerik 4y ago
  Javascript was famously rushed out in ten days, and ended up eating the world.

chrisgd 4y ago

I received a turbografx16 handheld around 1991 for Xmas. It had a tv tuner and I had two games. I loved it but the battery life was so short I barely ever used it. To this day, I wish I had more patience and interest

pbj1968 4y ago

I always greatly enjoy the posts on this blog. Gotten me through some very slow days.