Future Project MSX2+ HB-F1 XV Msx Super Turbo...

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By Dhampird

Hero (584)

Dhampird's picture

13-07-2016, 19:46

I get an MSX2+ XV, still i have to update to 512kSRAM (i have here a diagram), change roms faster, change z80.
Meanwhile the components arrives, I began follow how CLK signals moves in the XV, also i found that the service manual XD or XDJ is not similar to XV at all, a lot of differences only with the CLK signal in XV, i made a XV CLK diagram , if i´m right in this diagram you can see where all CLK points goes in the XV.

Here the brown PCB detailed:

Problems how to install Turbo:

-It seems SONY MB670836 is a mistery, no pinout.
-Maybe that 3 CLK points in that IC are related with the "NORMAL to SLOW" feature speed in the slicebar?
-I dont know if that SONY MB670836 could handle more Mhz, or if in that 3 points there are anyone CLK IN or any CLK OUT, maybe conect that 3 CLK points to CLK´s out Turbo will be a problem.

I made 2 Turbo aproximation diagram installs:

Another way with Turbo CLK to MB670836?

Still i have to update RAM, and others, after that i´ll try Turbo, but i dont know if the MB670836 could manage more Mhz. Also i have to found the disk drive needed point to a diode. Any clues or suggestions are welcome. ;)

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By Alexey

Guardian (1718)

Alexey's picture

13-07-2016, 23:31

Here's some info I found:

http://www.basshp.msxall.com/xv.html

I wanted to do the RAM upgrade as well, but I was afraid to damage the blue tracks on the board. If those get broken, the machine is a brick.

By Dhampird

Hero (584)

Dhampird's picture

14-07-2016, 23:24

Hello, yes the blue tracks seems be fragile and difficult a lot to follow the tracks on the motherboard also. Once i get the parts i´ll try better this 512K SRAM update:

http://www.tabalabs.com.br/msx/512k_f1xv/index.htm

By Dhampird

Hero (584)

Dhampird's picture

13-09-2016, 02:07

By iamweasel2

Champion (486)

iamweasel2's picture

13-09-2016, 03:12

Wow ! That is amazing ! What is the z80 clock at turbo mode? 7 mhz?

By Meits

Scribe (5184)

Meits's picture

13-09-2016, 14:10

I remember 7MHz destroying the PSG and I've never seen a Konami game go faster on 7MHz as they're (mostly, if not all) interrupt based.
Great demonstration Smile

By Louthrax

Paragon (1846)

Louthrax's picture

13-09-2016, 14:20

Meits wrote:

I remember 7MHz destroying the PSG and I've never seen a Konami game go faster on 7MHz as they're (mostly, if not all) interrupt based.

Even if a game is interrupt-based, a 7Mhz CPU can speed up things when you have slowdowns. In Knightmare, frames are skipped when computations are too intensive (too much ennemies), so the game displays 30 FPS instead of 60. Having a 7Mhz CPU will reduce those 30 FPS slowdowns, and indeed speed-up the game (even if no change at all in normal cases).

By tvalenca

Paladin (705)

tvalenca's picture

13-09-2016, 19:28

Alexey wrote:

I wanted to do the RAM upgrade as well, but I was afraid to damage the blue tracks on the board. If those get broken, the machine is a brick.

Unless you fry a very rare chip that could not be replaced with a similar one (S1990 for example) NO MSX MACHINE could be definetely bricked. It sometimes would involve a ton of work, but almost always has a solution. IIRC, the fellow from basshp fixed a Sony with a scratched blue track and the fellow from Tabajara Labs fixed a WSX with sereral broken traces near Main RAM chips.

Louthrax wrote:

Even if a game is interrupt-based, a 7Mhz CPU can speed up things when you have slowdowns. In Knightmare, frames are skipped when computations are too intensive (too much ennemies), so the game displays 30 FPS instead of 60. Having a 7Mhz CPU will reduce those 30 FPS slowdowns, and indeed speed-up the game (even if no change at all in normal cases).

Our friend FRS said once to me that Konami games (not sure if most, some or few) only updates screen on half VDP interrupts, so we're talking about 30 FPS top. That's why slowdowns are noticeable on those games (remember that Konami used that HP64000 solution to develop msx games, which emulated a 4MHz Z80 instead of a 3,57MHz with waitstates)

By Louthrax

Paragon (1846)

Louthrax's picture

13-09-2016, 20:08

tvalenca wrote:

Our friend FRS said once to me that Konami games (not sure if most, some or few) only updates screen on half VDP interrupts, so we're talking about 30 FPS top. That's why slowdowns are noticeable on those games (remember that Konami used that HP64000 solution to develop msx games, which emulated a 4MHz Z80 instead of a 3,57MHz with waitstates)

Yes, most of the Konami games are 30 FPS, but Knightmare definitively is 60 FPS (maybe also other non-megarom games like Atheltic Land, Pippols...).

By sd_snatcher

Prophet (2865)

sd_snatcher's picture

14-09-2016, 03:45

Very cool, but - hey - some credits would be nice, wouldn't they? ;)

By Dhampird

Hero (584)

Dhampird's picture

14-09-2016, 14:49

Hello, yes, of course, sorry for not mentioning you when i uploaded the video, now i added a video description below, and Credits at the video end.

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