FASTCHIP 400/800

[walter_J64bit]

Anyone have one these? What up with this chip? There doesn't seem to much info about on the net.

[Sub(Function(:))]

It's just an alternate floating point package. On the 400/800 the floating point chip has it's own ROM.

 

It speeds up calculations, and fixes a few bugs, I think I still have mine in it's box somewhere.

 

i think there is a review in Antic.

[Faicuai]

[quote name=Sub(Function()' timestamp='1315741090' post='2369755]

It's just an alternate floating point package. On the 400/800 the floating point chip has it's own ROM.

 

It speeds up calculations, and fixes a few bugs, I think I still have mine in it's box somewhere.

 

i think there is a review in Antic.

 

...Do you plan to keep it?... If not, let me know.

 

F.

[+David_P]

I think B&C still ist it on their web page.

 

Plus the source and object code are out int he wild as well - so if you want, you can build your own XL/XE ROM with it as well...

[kurtm]

I think B&C still ist it on their web page.

 

Plus the source and object code are out int he wild as well - so if you want, you can build your own XL/XE ROM with it as well...

 

For that matter, In the past couple years, ClausB released a replacement FP ROM that is supposed to be better than FASTCHIP. (Which is not surprising consider the type of coding folks know how to do for 6502 now, versus 20 years ago). At some point I want to do an XL/XE ROM with his code for FP.

[walter_J64bit]

At some point I want to do an XL/XE ROM with his code for FP.

 

That would be nice to have!

[ijor]

IIRC, the Fast Chip code was also part of Omnimon (at least the XL version).

[fibrewire]

I'm still looking for one of these. If found, please make an offer.

 

Some pictures for reference:

[Sub(Function(:))]

I am still trying to get back home. But, There is just too much to do at work at the moment (new manager, and everything is status Urgent/Panic)

 

Now the family are coming over from Greece to Berlin for christmas, so it looks like I won't get back over there until the new year

 

I'll ask if my brother-in-law can have a look for it, and bring it over.

[bfollett]

Since I don't think any programmers took into account the possibility of a faster atari 8 bit, wouldn't this chip just make most games run too fast to even be played? Seems to me you'd need a backup stock machine just so you could use the vast majority of your software at the correct speed. Unless ofcourse there's some sort of keystroke to use the original floating point routines.

 

Bob

[Sub(Function(:))]

Since I don't think any programmers took into account the possibility of a faster atari 8 bit, wouldn't this chip just make most games run too fast to even be played? Seems to me you'd need a backup stock machine just so you could use the vast majority of your software at the correct speed. Unless ofcourse there's some sort of keystroke to use the original floating point routines.

 

Bob

 

It's a floating point package upgrade. Not many games use floating point. They generally rely on "CPU" maths. INC/DEC/ADC... I had one in my 400 for many years and had no problems with games.

Edited December 2, 2011 by Sub(Function(:))

[+Larry]

I had one of these years ago in my 800. The improvement in BASIC programs was at times quite noticeable. The biggest improvement (IIRC) was in trig functions, but of course most folks don't use them very much in programs.

 

Here is the aforementioned Antic review:

 

http://www.atarimagazines.com/v1n4/fastchip.html

 

-Larry

[bpj1138]

What was the FP format on the ATARI? I'm under the impression it was BCD?

[sloopy]

I do believe I have seen source for this floating around the net, interesting read...

 

 

sloopy.

[Chilly Willy]

What was the FP format on the ATARI? I'm under the impression it was BCD?

 

It consists of six bytes, of which five are BCD digits and one is a biased binary exponent and sign. You can find the complete assembly listing for the standard FP package in the Atari Basic assembly listing found in various places on the net.

[Sub(Function(:))]

Hi All,

 

I finally got my Newell "Fastchip" from Greece.

 

I have taken some photo's to be found in my dropbox (zipped): http://dl.dropbox.com/u/3484589/FastChip.zip

 

I replaced the standard FP routines of the XL/E OS with the ones from this chip, and this image seems to work as an OS replacement.

 

I also did some quick benchmarks, using ATARI BASIC code from some of the fastchip reviews. I also did the same test against the Fastmath.rom image found here;

 

http://ftp.pigwa.net/stuff/collections/nir_dary_cds/ROMS/

 

Standard OS and Math = 486

Fastchip in Standards OS = 171

Fastmath.rom = 138

 

Times are seconds using the onboard RTC registers 18,19 & 20 on a PAL emulator (atari800macX), I don't have any 27128's to put these image in a real machine

 

Also: Looking at the Hex dump of the fastmath.rom, it has no Newell copyright "CPYRT 1981 MARSLETT" as the Fastchip does so it looks like it is a complete rewrite by some one.

 

If any one wants the Fastchip please PM me.

[Jeffrey Worley]

On 12/2/2011 at 10:39 AM, bfollett said:

Since I don't think any programmers took into account the possibility of a faster atari 8 bit, wouldn't this chip just make most games run too fast to even be played? Seems to me you'd need a backup stock machine just so you could use the vast majority of your software at the correct speed. Unless ofcourse there's some sort of keystroke to use the original floating point routines.

 

Bob

I had an 800 with a bad mathpack rom.  It wouldn't boot with the rom installed so I pulled it and left the socket empty.  The machine works just fine with the rom missing entirely and the vast majority of software still runs.  Basic will not start without it, but there's not a lot of stuff that uses floating-point math, so you are pretty safe with this upgrade.  The things that DO use floating point will benefit and are the sort of thing you WANT to run faster anyway.

 

Just like on any other computer, floating point math is slower than integer math, so programmers avoid it it possible.

 

Jeff

[Rybags]

I seem to remember reading somewhere here of someone putting a 2K SRAM in place of the FP Rom.

That would in theory, in a clunky sort of way allow switching between stock/fast Roms, which could simply be loaded as binary files.

As games go, for the most part it'd only be Basic games.  And for the most part the speedup wouldn't be all that huge and in most cases beneficial anyway.

[Jeffrey Worley]

8 hours ago, Rybags said:

I seem to remember reading somewhere here of someone putting a 2K SRAM in place of the FP Rom.

That would in theory, in a clunky sort of way allow switching between stock/fast Roms, which could simply be loaded as binary files.

As games go, for the most part it'd only be Basic games.  And for the most part the speedup wouldn't be all that huge and in most cases beneficial anyway.

I tried replacing the bad 2716 eprom with a 27c16 eeprom.  The system really freaked out.  I think there is a timing issue, a slower rom is needed than the one I have to play with.  I still have the personality board with the missing rom and use it occasionally as a test board.

 

best,

 

jeff