Subject: Re: Re: [TI994A] Running the CF7+ on the SNUG version 32k-16 Bit Buss @ 3.58 Mhz

From: [email-masked]
Date: Wed, 07 Apr 2010 11:44:01 -0500 (CDT)

Yes, Owen this allows the CF7+ to function with other 32k memory options out there the 32k-16 being only one of them but then the switch allows you to toggle back to original CF7+ operation when needed. Keep in mind this does not change the 4A from 3.0 Mhz speed as that requires the crystal mod to be able to run at 3.58 or 4.0 Mhz.

Apr 7, 2010 10:56:14 AM, [email-masked] wrote:

Wow--- looks sharp there!!!!  That's a pretty nice camera too.  So this allows you to run a CF7 device with a modified console (32k built in and a higher MHz)?

Owen Brand

Opry99er.com

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From: Owen Brand <[email-masked]>
Date: Wed, 7 Apr 2010 12:48:42 -0400

Thanks-- very nice mod, Richard.  Wish those SNUG consoles were more  
readily available.  Just as a question, the 16 bit buss, does that  
eliminate the need for the multiplexing?

Owen Brand
Opry99er.com

On Apr 7, 2010, at 12:44 PM, [email-masked] wrote:

>
> Yes, Owen this allows the CF7+ to function with other 32k memory  
> options out there the 32k-16 being only one of them but then the  
> switch allows you to toggle back to original CF7+ operation when  
> needed. Keep in mind this does not change the 4A from 3.0 Mhz speed  
> as that requires the crystal mod to be able to run at 3.58 or 4.0 Mhz.
>
> Wow--- looks sharp there!!!!  That's a pretty nice camera too.  So  
> this allows you to run a CF7 device with a modified console (32k  
> built in and a higher MHz)?
>
> Owen Brand
> Opry99er.com
>

---

From: tursi <[email-masked]>
Date: Wed, 7 Apr 2010 10:49:01 -0700 (PDT)

> Thanks-- very nice mod, Richard.  Wish those SNUG consoles were more readily available.  Just as a question, the 16
> bit buss, does that eliminate the need for the multiplexing?

On the RAM, yes. The RAM chips sit on the 16-bit bus by piggybacking on 
the console ROMs (which are also on the 16-bit bus), and then a couple of 
small changes are made to the console so that the multiplexer does not 
engage for RAM anymore. (A second mod adds a switch to turn the wait-state 
generator back on so that it runs at normal speed, for timing-important 
apps).

Thierry's work on the wait state generator suggests that most, if not all 
devices on the TI, with the exception of the PEB 32k card, work with most 
of the console wait states disabled anyway, he has a nice discussion of 
the mods which have the potential to boost speed even more (ie: no wait 
state to the video chip), even with the 8-bit bus (he manages to squeeze 
two memory accesses into one CPU cycle, so that the multiplexer runs 
faster than the CPU and the CPU doesn't have to wait even for that.) It's 
an interesting read, though I haven't tried it so I don't know how 
practical it is - in theory it should be even faster than the 16-bit RAM 
mod since things like video, sound, and peripheral access no longer cause 
wait states, but I wonder how much software breaks talking to the video 
chip. ;)