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[NC Series] Dreamwriter 225, The missing link

Started by robcfg, 11:01, 09 September 13

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Gryzor


TFM

TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

MaV

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.

Black Mesa Transit Announcement System:
"Work safe, work smart. Your future depends on it."

MaV

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.
Black Mesa Transit Announcement System:
"Work safe, work smart. Your future depends on it."

TFM

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]
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

MaV

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.

Black Mesa Transit Announcement System:
"Work safe, work smart. Your future depends on it."

robcfg

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!

Gryzor


SyX

With a lot of delay, but i'm here :)

Thanks robcfg!!! You always get the more sexy machines  :D ;)

gnokketto

Sorry Guys, The question are simple can i Put rom of NC150 to NC100 8)  ??

Prodatron

#35
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

GRAPHICAL Z80 MULTITASKING OPERATING SYSTEM

gnokketto

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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