Hidden MSX hardware

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By RetroTechie

Paragon (1414)

RetroTechie's picture

14-11-2016, 08:21

Indeed great find this ZEAL E/Paso! Big smile

First thought was that maybe the S3527 was used simply as a CMOS version PSG. But in that case, you'd need another (custom) IC to control things like keyboard, various chip selects and so on. Only candidates are those 2 modem IC's on the left, which have their own task... so no. Or you'd need a bunch of discrete logic (74xxx like), of which there are very few on the board. So no.

Conclusion: hardware must be (mostly) MSX compatible. That is: I/O addresses of PSG, VDP, keyboard control and so on.

Which leaves memory layout, and ROM contents. If you have a close look at the S3527 (with pinout from datasheet in hand), then:
a) It's clear PSG output is used.
b) I don't see any /SLTxx signals leaving the chip. Maybe under the chip? Question Or: most chip selects for the ROMs come directly from the CPU, perhaps going through a logic chip or 2. Tracing a few of those connections would be fairly easy, and tell you a good deal more about the memory layout.

I'd guess a custom memory layout. Perhaps as simple as 32K ROM/32K RAM or something like that (no MSX-type slot fiddling! LOL! ), with more ROMs (fonts? extra application software? ...) paged in somehow.

It would be interesting to -temporarily- disable built-in ROMs, hook up an MSX1 ROM to S3527 /ROMCS signal, and see if it boots. But you'd have to be sure where RAM is in the memory map before even attempting that.

Probably I'd just leave it as-is for fun / display purposes or 'reverse engineering'. And perhaps dump the ROMs if you want. Sure, you could try & put in MSX ROM(s), do some modding, wire up a cartridge slot, but why? Poor use of this machine, and a basic MSX2 isn't expensive or hard to find.

msxholder wrote:

Looking at the Vram of the Zeal E/PASO it's d ram is 512 kb !

I agree with maxis; possibly 256K*4 chips were cheaper/easier to find, and they rewired them to behave as 64K*4 chips (read: 128K VRAM here).

By Lord_Zett

Paladin (798)

Lord_Zett's picture

14-11-2016, 17:25

its just great. get a msx2 rom or 2p and put it in it! dont save it use it. if not sad

By l_oliveira

Champion (504)

l_oliveira's picture

17-11-2016, 05:33

HD64180/Z180 has built in MMU so if they don't use MSX slots they don't need to use memory control functions of the S3527.

By l_oliveira

Champion (504)

l_oliveira's picture

17-11-2016, 05:52

maxis wrote:

BTW when Intel acquired NVidia they didn't kill their x86 Tegra line. Having Tegra within Intel doens't mean that Intel doesn't have a good skill to build x86 processors Cool

Intel didn't buy nVidia. It's possible that nVidia may buy Intel(lol) in the next couple years considering nVidia recent technological achievements with deep learning using GPU cores as CPU (for example processor modules being used on self driving cars which are currently the rage on the embedded industry).

There were never been a Tegra x86. Tegra is a embedded system (SoC) which contains ARM CPU core(s) + GPU meant to run tablets and cell phones (portable stuff). Which Intel competed with nVidia couple years ago. Intel had a lot of chips being used on HTC smartphones. nVidia won that battle by large margin. Even then, portable Intel stuff were also ARM based. Neither companies won that battle though. The champion on this business is Qualcomm with their Snapdragon SoC family.

Recently nVidia won a contract with Nintendo and their TEGRA product became the core of the new "Nintendo Switch" game system. Due to that nVidia retired their "Shield" range of products from the market. I believe they may do the same to the Tegra family as it's now being used by Nintendo and by any means it's simular to how Yamaha's huge contract with SEGA affected their business with ASCII. (delaying the MSX Turbo R VDP development back in 1989/1990)

By madscient

Master (177)

madscient's picture

20-04-2017, 03:53

Mitsubishi Telecom Station ML-TS100


MSX2 with built-in 9' Monochrome CRT. intelligent modem, FDD, and handset.
A noteworthy feature is that the CPU is HD64180 @ 6.144 MHz.
Between MSX2 core and builtin intelligent modem is connected via internal UART of 64180.

By Piter Punk

Master (170)

Piter Punk's picture

20-04-2017, 06:26

Amazing! Very nice find!

Those scans are from where?

By madscient

Master (177)

madscient's picture

20-04-2017, 06:55

Product picture is from an ad.
https://archive.org/stream/Io19878_534/IO_198708#page/n99/mo...

The specifications are from Mitsubishi's technical report. (browsable in Japanese National Diet Library)
http://iss.ndl.go.jp/books/R000000004-I3141616-00

By Piter Punk

Master (170)

Piter Punk's picture

20-04-2017, 07:28

Nice. I saw that ML-TS100 have a very small ad at IO 198706 (page 101 in PDF) and in IO 198707 (I didn't mark the page).

madscient wrote:

The specifications are from Mitsubishi's technical report. (browsable in Japanese National Diet Library)
http://iss.ndl.go.jp/books/R000000004-I3141616-00

Maybe I am doing something wrong. Many times in my researches I follow links that brings me to NDL, I give a look the article's summary (title, author, source, etc), it seems good, but this is all I can see. There is no way that I can see the article contents.

Great that you found those specifications. They show what's the most powerful MSX2 released, 512KB RAM! Wow!

By madscient

Master (177)

madscient's picture

20-04-2017, 08:18

Piter Punk wrote:

Maybe I am doing something wrong. Many times in my researches I follow links that brings me to NDL, I give a look the article's summary (title, author, source, etc), it seems good, but this is all I can see. There is no way that I can see the article contents.

Exactly right.
To browse the all contents, you should go to NDL, it's so hard for foreigners and also daytime workers in JapanSmile
Therefore, I have retrieved the copy of contents from paid search service via FAX:
http://db.g-search.or.jp/

Piter Punk wrote:

Great that you found those specifications. They show what's the most powerful MSX2 released, 512KB RAM! Wow!

That largest RAM was used for multi-tasking on "Telecom-OS" its specified OS.
Following tw is from the one who programmed Telecom-OS (Japanese):
https://twitter.com/t_okada/status/789820850367111168

By Algorythms

Champion (276)

Algorythms's picture

20-04-2017, 08:58

I heard rumours in the 90s that the Japanese hospitals invested in machines that were eighter based on the Turbo R, or at least used the R800 processor. Maybe worth checking out, but I bet they were all dumped in the garbage years ago.

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