Wiki editing discussion

Enlighted (6104)

07-01-2019, 14:04

mars2000you wrote:

Read comment 646 on this page: https://2ch.live/cache/view/i4004/1031735952

This comment does not specifically mention MB-H50N and it can not be considered reliable.
On the main board I see two MB81464 (2 x 64K x 4 bits). MSX2s often use similar RAM and never 128kB in 64KB machines. This comment is unlikely to be true.

The AD on the site below seems to say that the unit was sold alone.
https://twitter.com/i/moments/866964646787375105
Maybe MB-H50N is the packaging with keyboard included or something else.

By rderooy

Paladin (686)

07-01-2019, 14:19

To me it just does not sound convincing. And that includes that short comment on 2ch.live, which really only talks about 64kB being cheaper than 32kB in 1986, and Hitachi using 128kB in the MB-H50 with only 64kB usable, with no reference to the 'N' variant, and no evidence to backup his claim.

According to Google translate it reads:

Machines late in MSX 1 are loaded without meaning 64 K (unless they are also used in DOS), 64 K is becoming cheaper than 32 K RAM.
At the same time I think that Hitachi's MB-H50 saw it if it had been decomposed, but 128K RAM made by NEC is on it. Of course the remaining 64K is never used at all on MSX1.

There must have been a different reason for them to give it the 'N' suffix. And if 128kB from NEC was cheaper than 64kB in 1986 for Hitachi, then I'm sure that at least by 1988 when the 2+ systems came out, it would have been for everyone and Sony, Sanyo and Panasonic would have put 128kB in the 2+ systems.

By mars2000you

Enlighted (6430)

07-01-2019, 15:04

I guess that adding a memory mapper means more expensive machine. Besides, for non-professionnal Japanese MSX users, 64kB RAM has always been the higher norm before Turbo R.

By rderooy

Paladin (686)

07-01-2019, 15:26

Mars, I agree that adding a memory mapper to a machine would make it more expensive, but most MSX2 systems have a memory mapper, even those with just 64kB RAM. So that point is moot.

Personally I would prefer to roll-back the changes you made the the MB-H50 page. I don't feel confident that the difference between the non-N and the N model is the amount of inaccessible memory. I also consider the 128kB, for the time being, to be hearsay unless someone can provide more compelling evidence such as PCB pictures, or a clear mention of it in one of the Japanese magazines.

By mars2000you

Enlighted (6430)

07-01-2019, 15:38

Of course, we need PCB pictures of the N version. I will adapt the text to make it less definitive.

By Grauw

Ascended (10706)

07-01-2019, 15:39

引用:

Machines late in MSX 1 are loaded without meaning 64 K (unless they are also used in DOS), 64 K is becoming cheaper than 32 K RAM.
At the same time I think that Hitachi's MB-H50 saw it if it had been decomposed, but 128K RAM made by NEC is on it. Of course the remaining 64K is never used at all on MSX1.

That doesn’t say the upper 64K is inaccessible or unusable, or that there is no memory mapper. It says >64K is never used in MSX1 software, so not very generally useful, which is sorta true. But there are MSX1 machines with memory mapper, e.g. the CX5MII, and I use it in VGMPlay running on Nextor.

By rderooy

Paladin (686)

07-01-2019, 16:10

@Grauw very true. To me the posting is very vague and poses more questions then answers.

p.s. there is one MSX1 game that requires 128k, SWIV.

By Manuel

Ascended (19300)

08-01-2019, 07:45

I wonder what they were thinking when releasing SWIV like that.... Practically no one with an MSX 1 could run it.

By RetroTechie

Paragon (1563)

08-01-2019, 08:48

rderooy wrote:

Personally I would prefer to roll-back the changes you made the the MB-H50 page. (..) I also consider the 128kB, for the time being, to be hearsay unless someone can provide more compelling evidence such as PCB pictures, or a clear mention of it in one of the Japanese magazines.

Second that. Looking at the pcb picture, adding 64K more RAM would also require a redesigned circuit board. For otherwise similar machines, that is very unlikely unless there was some important reason for it. So unless proven otherwise, I'd consider "someone got it wrong" more likely than "very different machines under the hood".

Manuel wrote:

I wonder what they were thinking when releasing SWIV like that.... Practically no one with an MSX 1 could run it.

Probably targeted at diskless MSX2 machines. But using MSX1 graphics capabilities (lazy programmers? who knows) such that it happened to work on 128K equipped MSX1's as a 'bonus'.

Personally I'd have slapped it on a single sided disk, if only to cut back on load-128K-from-tape support calls. And for those inclined, MSX1 + floppydrive also works...

By gdx

Enlighted (6104)

08-01-2019, 09:42

According this old auction below, the MB-H50N is only written on the box not on model sticker nor on MSX case. The MB-H50 seems to be widespread because of cheap MSX2s that have arrived quickly. It had to be sold in Japan during less than a year.
https://page.auctions.yahoo.co.jp/jp/auction/t616893186