MAMEWorld Forums - EmuChat - an archived message regarding history-wise of pps4 emulation in MAME

Before Mattel led emulation happened earlier...with PPS 4/1 finally happening...

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2021-02-26

added MM76 disassembler and preliminary PPS-4/1 MCU core [hap]

New machines marked as NOT_WORKING
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Electronic Master Mind (Invicta) [hap, Sean Riddle]

https://github.com/mamedev/mame/commit/2f02c96baffbe8a628ab2d4bbc325efe945100d7

2021-02-14

added MM5799 MCU emulation [hap]

New working machines
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Basketball (Mattel) [hap, Sean Riddle]
QuizKid Speller [hap, Sean Riddle]

New working clones
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QuizKid Racer (MM5799 version) [hap, Sean Riddle]

https://github.com/mamedev/mame/commit/147b5e72a401de8478df778a1f00d3a4c1be44f8
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....Juergen Buchmueller had written a cpu core for the Rockwell cpu earlier.

https://github.com/mamedev/mame/tree/master/src/devices/cpu/pps4

https://github.com/mamedev/mame/blob/master/src/devices/cpu/pps4/pps4.cpp

I was curious about the cpu since my interest was towards the Mattel led games
that used processor and this was about the time some of the led games were starting to be emulated just a year before lcd hardware games were then being emulated.

I asked Stiletto about PPS 4/1 and Mattel led games in 2014. Another great example of why
I enjoy reading some of the stuff Stiletto mentions from years earlier and this is
why I wanted to post this now that PPS 4/1 has happened and in MAME source code and will be in next official release.

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Re: Mattel Electronics handheld games
From: Stiletto
12/15/14

> After reading hap's post, I am looking forward to seeing if this gets any of the
> Mattel games closer to being emulated. I hope the cpu support pps4.c that Juergen had
> added for other hardware games is what helps start emulation of any of the Mattel
> games even though I figure some update might be needed for the cpu code first before
> a driver is created.

Yes, the motivating factor here was not more handheld simulation (although that would be cool). Basically, Juergen recently randomly rewrote the PPS-4 emulation core to match the original documentation archived by Bitsavers. (The previous core was what Micko had originally imported from PinMAME around 2008 or so, plus another round of modernization in 2010 or so.)

The reason Juergen rewrote the core was that some German had got in touch with him regarding a rare unemulated German computer (don't look at me, I've never heard of it) that used the Rockwell PPS-4 as its main CPU. But after Juergen's modernization this required him to touch the Gottlieb System 1 emulation to ensure it still worked. Juergen has yet to submit his German computer driver to MESS, but it's coming. Hey, I'm happy any time Juergen takes another stab at MAME/MESS, no matter what he wants to work on.

But it reminded me that back in 2008 when Micko was copying and updating CPU/video/audio cores from PinMAME (Intel 4004, Rockwell PPS-4, a few others) that he'd got in touch with me to see if I could track down other systems (arcade/console/computer/handheld/other) that used these CPUs, possibly even ROMs, so that he could further test these cores on more than just pinball ROMs. So this time, I dug my notes up and dug out the PPS-4 notes and gave them a second pass/update and posted it to the group rather than just Micko. No ROMs, but I saw that I'd made a note about the Mattel handhelds. hap caught onto that right away and thought to bring it to Sean's attention. And here we are.

Yes, I'm thinking that the Rockwell B6000 series must be related to the Rockwell PPS-4 series. I guess someday we will find out how.

- Stiletto
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