True 16MHz Mode

New sub forum for version 2 of the STF remake board.
User avatar
Smonson
Posts: 275
Joined: Sat Oct 28, 2017 10:21 am

Re: True 16MHz Mode

Post by Smonson » Tue May 28, 2019 6:05 am

exxos wrote:
Mon May 27, 2019 3:11 pm
Mono can do 640x400, but I assume would need a new shifter to cope with moving that to 4 and 16 colours.
The shifter doesn't care what the resolution is, only the colour depth. It's the MMU/Glue controlling hsync, vsync, and the number of shifter LOADs per line that decides the video frame parameters.

If you wanted 640x400 in 4 colours on the double-speed machine you just need to get the shifter into mode 1, and the MMU/Glue into mode 2 (mono) so that a 400-line image is produced. I don't know the details of how you double the number of LOADs per line - I'm leaving that as an assumption to be filled in by someone else :)

User avatar
exxos
Site Admin
Site Admin
Posts: 7428
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: True 16MHz Mode

Post by exxos » Tue May 28, 2019 8:40 am

The GLUE doesn't get speeded up. I believe the MMU being double clocked "sees" the DE pulses twice from the GLUE. So the mod done on the GLUE is to only allow the DE pulse when the CLK2 is high. So in effect reduces the number of pulses by 2.. actually pretty clever really.

I think it was a AND between the DE and CLK2. So if the shifter was running x4 (64Mhz) then I would assume the AND would be with DE and 4MHz clock.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

kodak80
Posts: 115
Joined: Sat Oct 21, 2017 1:14 am
Location: Brisbane, Australia
Contact:

Re: True 16MHz Mode

Post by kodak80 » Tue May 28, 2019 9:41 am

16mhzPCBs.jpg
16mhzPCBs.jpg (227.18 KiB) Viewed 1025 times
Purple PCBs arrived today from OSH. Is there a parts list for the components? BRD doesn't give this information.

Also, once assembled, how is it wired to the Remake Board?

Very keen to get my 2 boards running at 16mhz... :D
Atari Falcon 030 | Atari 1040 STE | Atari 1040 STFM | Atari 1040 STF | Kryoflux & Supercard Pro Flux boards
Admin of Atari ST Review Magazine Archive: http://www.chillichai.com/atari-st-review

User avatar
exxos
Site Admin
Site Admin
Posts: 7428
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: True 16MHz Mode

Post by exxos » Tue May 28, 2019 11:11 am

kodak80 wrote:
Tue May 28, 2019 9:41 am
Purple PCBs arrived today from OSH. Is there a parts list for the components? BRD doesn't give this information.

Also, once assembled, how is it wired to the Remake Board?
I don't know of either yet. I need to build one up for my machine and work out the resistor values. Of course there will be some images how to wire it (but I need to do that myself yet)

The IC's are probably going to be 74ACT161 & 74LVC1G08 The OSC is 32MHz (or really should be 32.084988MHz )

So once I have built and fitted mine, and got it all stable, I will post parts list and how to fit it. Though I may not get chance until next week :(
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

User avatar
Icky
Moderator
Moderator
Posts: 1276
Joined: Sun Sep 03, 2017 10:57 am
Location: UK

Re: True 16MHz Mode

Post by Icky » Tue May 28, 2019 6:28 pm

Finally got round to doing a video of Frontier Demo and a stock STFM and the STF Remake in True 16MHz Mode.


User avatar
PhilC
Moderator
Moderator
Posts: 1647
Joined: Fri Mar 23, 2018 8:22 pm

Re: True 16MHz Mode

Post by PhilC » Tue May 28, 2019 7:48 pm

That looks so much better now. Next up, exxos's 50mhz mod LOL.
If it ain't broke, test it to Destruction.

User avatar
exxos
Site Admin
Site Admin
Posts: 7428
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: True 16MHz Mode

Post by exxos » Tue May 28, 2019 10:13 pm

I think the spinning ship wheel thingy at 2:20 really shows the speed increase. At 8MHz its pretty jerky and gets slower as it gets bigger. The 16Mhz seems pretty smooth and fast throughout.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

User avatar
PhilC
Moderator
Moderator
Posts: 1647
Joined: Fri Mar 23, 2018 8:22 pm

Re: True 16MHz Mode

Post by PhilC » Tue May 28, 2019 10:28 pm

You mean the space station? :P :lol:
If it ain't broke, test it to Destruction.

User avatar
exxos
Site Admin
Site Admin
Posts: 7428
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: True 16MHz Mode

Post by exxos » Tue May 28, 2019 10:48 pm

PhilC wrote:
Tue May 28, 2019 10:28 pm
You mean the space station? :P :lol:
Ah is that what it is then :)
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

User avatar
Icky
Moderator
Moderator
Posts: 1276
Joined: Sun Sep 03, 2017 10:57 am
Location: UK

Re: True 16MHz Mode

Post by Icky » Thu May 30, 2019 7:39 am

Built up a 16MHz board last night but unfortunately did not have time to test as it was the small hours of the morning.

I expect exxos will be testing his today way before me - challenge laid down :P

After the mess-o-wires to patch the ALPHA board to True 16MHz Mode I am looking to put this one in with a bit more elegance (he says remembering how rubbish his soldering is :))

My plan is to replace all the resistors of the CLK lines of the ALPHA board with headers so that I can plug in from this 16MHz board to the various points. Will also look at hot snot gluing the 16MHz board where the ALPHA Remake text is on the top of the board once working.

If you look at the image of my ALPHA running at 16MHz, you can see I am tapping into the CLK line resistors. E.g. the orange boxes of the CLK lines to the MFP 68901 and the other to the DMA (or in my case the NOT SO NASTY DMA :)). Those resistors will be removed and headers put in their place so I can tap the 16MHz board in easily with some jumper wires. Also give me an excuse to label the wires. :)

IMG_3797.jpg
IMG_3797.jpg (158.34 KiB) Viewed 892 times

Note: Below is a pic of my 16MHz board and the provisional components I have used. These are untested as of yet and there are some track cuts to do as well on the ALPHA board. Once we have these 16MHz boards working we will post full instructions.

  • 2 x 1uF 0805 (one of these is soldered on the underside of the board - I left this one as the last component to put on by hand
  • 5x 33R 0805 - Have currently gone with 33R as that is the value of the original resistors on the CLK lines. These could change.
  • 1x SN74LVC1G08DCKR
  • 1x MC74ACT161DG
  • 1x OSC - 32.084988MHz
IMG_3965.jpg
IMG_3965.jpg (171.47 KiB) Viewed 892 times

Post Reply