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General Category => NC100, NC200, PCW, PDA600 - the rest of the Family! => Topic started by: robcfg on 11:01, 09 September 13

Title: [NC Series] Dreamwriter 225, The missing link
Post by: robcfg on 11:01, 09 September 13

Hello everyone!


Last week I got a Dreamwriter 225 computer, which belong to a line of computers made by Nakajima for NTS, with the same aspect as the NC series range, but with a Nec V20 processor instead a Z80 one.


The 225 is the first one in the Dreamwriter range, and I noticed that the manual that appeared in the ebay picture, was actually an NC100 manual with a piece of paper with the NTS logo on top of the Amstrad one.


My surprise came when I switched it on, and it was actually a rebranded NC100!


Also, the rom is a 512kb one, but the actual contents would fit in a 256Kb one, and has a slightly different version of the NC100 rom, including the NC150 version of the BBC basic.


So far, the different machines in the NC series identify themselves in the settings menu as follows:




   
   
   
   
   
   
   
   
   
Model NameName in settings menu
Amstrad NC100 (UK)Amstrad NC100 v1.00
Amstrad NC100 (DE)Amstrad NC100 v1.02
Amstrad NC100 (DK)Amstrad NC100 v1.02
Amstrad NC100 (SE)Amstrad NC100 v1.02
NTS Dreamwriter 225Amstrad NC100 v1.06
Amstrad NC150 (FR)Amstrad NC150 v1.10
Amstrad NC150 (IT)Amstrad NC150 v1.11
Amstrad NC200 (UK)Amstrad NC200 v2.01


Beyond the 225 model, all Dreamwriters come with a Nec V20 processor fitted, and special software written for NTS such as typewriting tutorials for schools.


My guess is that a NC100 can be fitted with the Dreamwriter 225 rom for an updated basic.


In a few days, I'll upload the 225 rom the the NC Series page, and also add the device scans. The board is the same NA 999-32142 Board documented her in the wiki.


Cheers!
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: MacDeath on 19:49, 14 September 13
The sad part with those machines : you couldn't plug them on a TV.


those portable device could have been better with such a feature.
Many still don't (iPad ? on my TV ? never...)
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: mr_lou on 21:43, 14 September 13
Quote from: MacDeath on 19:49, 14 September 13The sad part with those machines : you couldn't plug them on a TV.

Give one to Bryce for a few days, and he'll add all sorts of plugs so you can connect that thing to whatever you want.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Bryce on 12:34, 15 September 13
Quote from: MacDeath on 19:49, 14 September 13
The sad part with those machines : you couldn't plug them on a TV.


those portable device could have been better with such a feature.
Many still don't (iPad ? on my TV ? never...)

The whole display circuitry isn't at all suitable for a TV signal. A TV out socket would have meant adding a huge amount of additional components just for this one socket.

Bryce.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: MacDeath on 17:20, 15 September 13
could have been an external add-on then.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Bryce on 20:58, 15 September 13
Not really. Those computers don't have a screen RAM as a CRT computer has, so it would be a very complicated and expensive add-on.

Bryce.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: mr_lou on 06:12, 16 September 13
Quote from: Bryce on 20:58, 15 September 13Not really. Those computers don't have a screen RAM as a CRT computer has, so it would be a very complicated and expensive add-on.

Be as modest as you want, but we all know that you can hook up a VGA screen to a coffee machine if you want.  :)
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Bryce on 08:40, 16 September 13
My Coffe machine is HDMI only. There was no room for VGA circuitry after I'd added the W-Lan and Bluetooth modules :D

Bryce.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: robcfg on 09:11, 16 September 13
No Megaflash?  ;D
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Bryce on 09:32, 16 September 13
No, but it wouldn't work on the NC100 either :(

Bryce.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Gryzor on 15:52, 16 September 13
Very interesting, had never before heard of the machine - let alone the fact that it's a NC100 sibling.


Interesting choice of CPU. Why would they go for that one - I would assume it was more expensive?
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Bryce on 17:56, 16 September 13
The V20 wasn't Z80 compatible, it was an unlicenced 8088 Clone, so I doubt the NC100 ROM would work on the 255. There's a good chance that it was cheaper than the Z80 at the time, but it would have meant that a new PCB layout and modified firmware and software would be required as far as I know.

Bryce.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Gryzor on 18:07, 16 September 13
Yeah, when I first read it I thought "but this is not V80, that's quite different, ain't it? Reading the specs, it's not a bad CPU, so would it be cheaper indeed by then? I would assume Z80 and clones would be dirt-cheap at the time...
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: robcfg on 19:34, 16 September 13
The 225 is still z80, from that model onwards they are all fitted with a v20.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: TFM on 22:07, 16 September 13
Quote from: Bryce on 20:58, 15 September 13
Not really. Those computers don't have a screen RAM as a CRT computer has, so it would be a very complicated and expensive add-on.

Bryce.




Well, I don't see the problem. It has an RS232 port, so use some good old RS232 terminal. I'm sure everyone here has at least two somewhere in the attic, basement of that small room where all that stuff get stored.

Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: TFM on 22:11, 16 September 13
Oh, btw.... in this nice raw of computers the Dreamwriter does fit too....


It has a 3.5' drive too (sadly mine was crashed by some stupit british lad).


http://www.google.com/search?q=dream+writer+word+processor&tbm=isch&source=lnms&sa=X&ei=qHM3UpOmFKGM2gWKl4BQ&ved=0CAcQ_AUoAQ&biw=1024&bih=653&dpr=1 (http://www.google.com/search?q=dream+writer+word+processor&tbm=isch&source=lnms&sa=X&ei=qHM3UpOmFKGM2gWKl4BQ&ved=0CAcQ_AUoAQ&biw=1024&bih=653&dpr=1)



Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: robcfg on 23:20, 16 September 13
Well, finally found the time and I uploaded the Dreamwriter 225 pictures and rom file to the NC Series (http://www.cpcwiki.eu/index.php/NC_Series) page.


I'll scan the manual cover and software disk in the near future...  ;)


I think I have almost the whole Dreamwriter range but for the Dreamwriter 500, Dreamwriter IT (this is a Windows CE machine), and maybe the computer used by professors to get the data from the tests done in the class (I don't know if that was a different computer).


The list is:


Dreamwriter 225
Dreamwriter 325
Dreamwriter 100
Dreamwriter 200
Dreamwriter 400
Dreamwriter 450
Dreamwriter 500
Dreamwriter IT

From the list, the 225 has a Z80, while the others have a Nec V20. The 200 is a NC200 form factor computer (I think the 500 too). And the IT is quite a different beast.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Bryce on 08:39, 17 September 13
Quote from: TFM on 22:07, 16 September 13



Well, I don't see the problem. It has an RS232 port, so use some good old RS232 terminal. I'm sure everyone here has at least two somewhere in the attic, basement of that small room where all that stuff get stored.

?? You would still need to feed the RS232 with data, so it would need drivers or modify every program to output to RS232 and it would still only be text then, not a mirror of the real screen.

Bryce.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: arnoldemu on 09:48, 17 September 13
Quote from: Bryce on 20:58, 15 September 13
Not really. Those computers don't have a screen RAM as a CRT computer has, so it would be a very complicated and expensive add-on.

Bryce.
Hmmm... They do have screen RAM ;)

I think it's all part of the main ram like on CPC.


Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Bryce on 10:00, 17 September 13
Yes, but it will be a bitmap format suited for the LCD driver circuit, so a lot of hardware would be needed to create a signal that a monitor could accept.

Bryce.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: arnoldemu on 10:05, 17 September 13
Quote from: Bryce on 10:00, 17 September 13
Yes, but it will be a bitmap format suited for the LCD driver circuit, so a lot of hardware would be needed to create a signal that a monitor could accept.

Bryce.
yes of course.

Yes in this respect, not easy.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Bryce on 10:17, 17 September 13
A 6845 would do, but you would then need to find a way to format the data for it and a way for it to read the RAM without disturbing the CPU access. Major job.

Bryce.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: MaV on 11:21, 17 September 13
The V20 has an 8080 mode.

It's quite possible that the Dreamwriter xxx switches to it at start. The ROM software then would only have to adapt the Z80 specific mnemonics.

Speculation, but quite possible.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: TFM on 16:21, 17 September 13
Quote from: Bryce on 08:39, 17 September 13
?? You would still need to feed the RS232 with data, so it would need drivers or modify every program to output to RS232 and it would still only be text then, not a mirror of the real screen.

Bryce.


No problem. It can run CP/M [nb]You can download CP/M for the NC100 / 200 f.e. from Tims site.[/nb]and so once a single command is enough. IIRC something like


PIP SIO:=CRT




Easy!  8) :) 
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: TFM on 16:24, 17 September 13
Quote from: MaV on 11:21, 17 September 13
The V20 has an 8080 mode.

It's quite possible that the Dreamwriter xxx switches to it at start. The ROM software then would only have to adapt the Z80 specific mnemonics.

Speculation, but quite possible.


Interresting idea. What would be the advantage of the V20 over the 6 MHz Z80? Is it pricing?




Well, I can't imagine that they wrote the ROM new for another CPU, that would be a major task. So the 8080 mode seems not to be too far out of reality  :)
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Gryzor on 18:55, 17 September 13
Thanks for the pics! :)
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: TFM on 20:57, 17 September 13
Yepp, MaV's avatar is amazing  ;)
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: MaV on 15:08, 18 September 13
Quote from: TFM on 16:24, 17 September 13Interresting idea. What would be the advantage of the V20 over the 6 MHz Z80? Is it pricing?
Hm, that would need a profound comparison of the two chips.
I don't have any data on pricing, and 80's/early 90's data on pricing is probably impossible to get these days.

Much like the 8088, the V20's basic instructions take as few as two cycles (8088 min. 3 cycles?), but as soon as memory is addressed the cycle count takes a leap. It also has block- and test/bit/set-instructions. An 8088 can beat a Z80, and the V20 is ~30% faster than an 8088.
Unfortunately, I've not found any infos on the instruction cycles for the 8080 mode.

QuoteWell, I can't imagine that they wrote the ROM new for another CPU, that would be a major task. So the 8080 mode seems not to be too far out of reality  :)
On the other hand, the 8088 - and therefore V20 - has an equivalent instruction for any single 8080 instruction, so converting the ROM assembly code might have been as easy as building a script and slightly modifying the result.

Besides, you have to take into consideration that the company's long term strategy might have been to change the architecture. Since all but the first model are V20 based, this seems to be the case. A one time conversion of the ROM looks feasible then.

Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: MaV on 15:21, 18 September 13
Quote from: TFM on 20:57, 17 September 13
Yepp, MaV's avatar is amazing  ;)
Hehe.

That is the picture of Luis de Góngora y Argote. A passage of one of his works is in my signature.

Translation:
"Because in a village a poor lad has stolen one egg
He swings in the sun and another gets away with a thousand crimes"


That is ever so true now as it was then.
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: TFM on 15:38, 18 September 13
Quote from: MaV on 15:08, 18 September 13
An 8088 can beat a Z80

That remains to be prooven. I take the bet against evey 8088 coder here. The Z80 has a second register set, the 8088 not. I say the Z80 beats the 8088 when programmed right.  :)   8)   ;D  [nb]If I wouldn't say so, my life would end tragicly[/nb]
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: MaV on 12:01, 20 September 13
LOL! You need not fear for your life. ;) Yep, in a lot of cases you might be faster than an 8088, no doubt.

I wrote "can" on purpose.

The 8088 is a bit more complex to optimise for, because of the 4 byte prefetch queue. If it is empty - which happens when you have a string of fast operations - then you are down to the speed of fetching the commands from memory. A 2 clock cycle command then takes 4 cycles to execute, IIRC. So you need to rearrange the commands - if possible - to achieve better results.
Plus, a conventional CGA- or Hercules-graphics card inserts wait states, so you'll write and read slower to/from graphics memory.

This all is on top of my head, so take it with a grain of salt, until someone confirms or proves me incorrect.

Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: robcfg on 19:55, 11 October 13
Hi guys!


I got a swedish NC100! Yep, swedish. I didn't knew that even existed, but goddess Fortuna guided me to it  :)


I've already dumped the rom, and it works flawlessly on MESS.


It's also available on the downloads section of the NC series page here at the CPCWiki.


Scans will be available during the weekend.


Cheers!
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Gryzor on 19:09, 12 October 13
Nice man, thanks :)
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: SyX on 22:26, 25 October 13
With a lot of delay, but i'm here :)

Thanks robcfg!!! You always get the more sexy machines  :D ;)
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: gnokketto on 19:49, 13 December 23
Sorry Guys, The question are simple can i Put rom of NC150 to NC100 8)  ??
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: Prodatron on 22:01, 13 December 23
Quote from: gnokketto on 19:49, 13 December 23Sorry Guys, The question are simple can i Put rom of NC150 to NC100 8)  ??
The NC150 has a different Keyboard Matrix
Title: Re: [NC Series] Dreamwriter 225, The missing link
Post by: gnokketto on 22:13, 13 December 23
Quote from: Prodatron on 22:01, 13 December 23
Quote from: gnokketto on 19:49, 13 December 23Sorry Guys, The question are simple can i Put rom of NC150 to NC100 8)  ??
The NC150 has a different Keyboard Matrix
:'( :'( :'(  Thanks there is also another method to use tetris inside nc150 ?
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