1024MAK wrote:Post delivered on a Sunday
, nope, just took me a couple days to remember to post here about it
1024MAK wrote:Post delivered on a Sunday
troed wrote:exxos wrote:Arne tried replacing that 2mhz line with 4mhz, and it caused the same problem as to when the DE mod was not done at all.
The DE mod should work. [snip]
>> * A potentially most beneficial approach would be the one which involves
>> raising the clock frequency of the entire system to 10MHz or 12MHz.
>> noone can quote -exactly- the modification needed for video circuits.
>> I have a general
>> idea of how it might work, but a tested schematics would be so much
>> easier- so if you find one let me know
> Hmmm... I think that such projects are very hard for realize, even if you
>find all ST magazines involved.
Not necessarily. I played a little with that project and for a start raised
the system clock to 10MHz (40MHz oscillator). By declaring external
syncs to TOS and by supplying the correct (or I thought so) sync pulses
obtained by dividing the 500kHz signal, I obtained a standard-resolution
picture on a SM-124. From that to an extended resolution it should not
be very difficult to go. (My attempt was not completely successful as the
picture trebmbled slightly (about 10 pixels) left-right, so I did not get
everything exactly right- or else at higher CPU speed the picture
started too early after a hsync pulse nd the monitor maybe couldn't
handle it). It was all done with several 74F and 74HCT chips.
I didn't have time to finish it, but I prepared some connections on
the motherboard to make everything more reliable, and will try again
with a modified circuit. My problem is finding reliable information
on pixel clock rates and line width- somehow the numbers I have do not
add-up correctly to 35.7Khz .
exxos wrote:Possible, though I just assume its a RAM bottleneck slowing things down. I guess if GEM apps were run in Alt-ram and the CPU could access alt-ram at 16mhz, as well as TOS at 16mhz, then I would assume it would give a huge boost in GEM app speeds. I think AlanH was doing some Alt-ram boards a while back, but I will have to ask him if they are likely to be capable of running at 16mhz.
arf wrote:exxos wrote:Possible, though I just assume its a RAM bottleneck slowing things down. I guess if GEM apps were run in Alt-ram and the CPU could access alt-ram at 16mhz, as well as TOS at 16mhz, then I would assume it would give a huge boost in GEM app speeds. I think AlanH was doing some Alt-ram boards a while back, but I will have to ask him if they are likely to be capable of running at 16mhz.
Any news here? Would be great to see a 16 MHz board plus a MonSTer board, where the MonSTer runs with 16 MHz - RAM access, but also IDE would greatly benefit, I guess.
exxos wrote:Thanks, I had seen something about 8mhz to 10mhz, though the overclock was a double clock of the entire system
arf wrote:exxos wrote:Thanks, I had seen something about 8mhz to 10mhz, though the overclock was a double clock of the entire system
Do you mean that: http://www.stcarchiv.de/stc1992/09_gehtdoch.php -- a speedup of the whole ST bus system, overclocking it from 8 to 10 or even 12 MHz.
I know a few users running such a system since years.
Exxos: As a side note, I plan to discontinue the V1 series booster in favour for the V1.5 series in the new year. The last batch of V1's will be made over the next couple of weeks
Atari74user wrote:Just to check, the V1 is not switchable is that correct?
If that is correct, the V1.5 may be suitable to me, however again the Fast ROM is an option, and not mandatory?
The only reason I ask these questions is I actually don't want to tamper with my TOS 2.06 switcher already installed in my STFM, everything is stable and backwards compatible. However a 16MHz V1.5 switcher would be a welcomed addition, along with a Blitter. For my set up it would seem a pretty stable combination, as everything could be switched back to original TOS running at 8MHz without the Blitter on if needed.
Fantastic. This will be like a SST.
DarkLord wrote:Those are great results Chris. Congratulations on your success(s) so far.
I'm curious to see when you get the 68020 working how close (or better,
considering the ROM speedup), it will compare to something like the Pak
Thanks for all the hard work!
DarkLord wrote:Yes, I've got the Pak 68/3 board with a 40mhz 68030 and 40mhz 68882 in my STacy.
It's running TOS v3.06.
Umm, remind where I can download GB5 and I'll give it a shot.
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