이안은 뭐하니?

Now Z80 MSX card runs on 3.58Mhz as well.

But, I would like to test if it could run above the 3.58Mhz.

Now, I've tested it the 7Mhz, It is exactly 2 time clock of the MSX1.

WOW,

It's running.

The ticks just 42 now, (Original MSX takes 88)

But, It failed running GAME ROM.

I guess VDP failed to run on the 7Mhz.

So, I slight slow down it to 5Mhz.

It runs and took 60ticks but lessthan 88 ticsk.

Tested Game ROM too,

It works but, failing some sprite display.

I think that it is really fail to run VDP.

I want to make 4Mhz but, can't do it with APPLE II clock.

Someday will test with 4Mhz.

Maybe 4Mhz will run fine.

I'm testing 3.58Mhz MSX running mode but, even slight faster would be better than just normal as the MSX1.

Thanks

Hi everyone,

Z80 card speed didn't reach to 3.58Mhz original MSX.

The Z80 MSX card runs as based on the architecture of the Softcard and it runs 2.045Mhz.

This speed limit is due to the APPLE II BUS speed and Z80 internal structure.

But, I tryied to break the limitation of 2Mhz.

Anyway this is one small BASIC program to determine the system speed.

(Low numbers is faster. (60hz tick) )

It took 88 ticks.

My Z80 MSX card runs as below

(I'm calling it 2Mhz)

Looks very slow?

In fact, while running games, I didn't feel slow as the number says.

Most of games doesn't use loop timer, and they are used 60hz VDP interrupts.

So, It almost same speed on many of games.

And now, I want to make it faster. But, How?

Z80 card have a 512KB SRAM and decide to run the Z80 when it doesn't use APPLE II BUS but using only SRAM.

I tryied several times and finally got the result.

Let's run same BASIC to check speed.

Hmm.. Just little faster..  (I calling it 2Mhz+)

What's wrong?

In fact, BIOS+BASIC is in the SLOT0 and this area is APPLE IIe location.

And it couldn't run faster in the BUS area.

So, Now, I upload the BIOS+BASIC into the SLOT3(SRAM area) and switch it to use only SRAM by Z80.

Ok!! GOOD. 

It is the same ticks spend as the S/W emulator.

I manually Switch the PAGE of BIOS+BASIC configuration.

And it works can switch to 3.58Mhz from 2Mhz+.

But, failed to switch 3.58Mhz to 2Mhz+ on basic prompt.

I guess that it is due to switching timing while running the memroy.

So, move to Safer location and switch the PAGE0&1.

This small program would help to switch the PAGE configuration of MSX.

The Data is Z80 codes and direct control the SLOT memory configuration.

A0 means Lower nibble is 32KB Slot# and (00 00  00 00 (BIN)) is SLOT#0.

Before I set it AA(10 10 10 10) to use SLOT#3.

And you can see the ticks changed to 146(2Mhz+) from 88(3.58Mhz)

I'm considering to move the BIOS+BASIC to SRAM area not on APPLE II Memory area.

It would be better performance.

Anyway I have a bug(Bus conflict) when I used Multi running. So, I disable to run Z80 and 6502 at the same time.

It should work much better but, the BUS conflict bring something wrong.

I'm trying to solve this technical issue.

Anyway, It runs 3.58Mhz Z80.

Thanks

I've tested more MSX game ROMs.

Alll are working with good sound.

Bosconian

Runs little slow.

A few of games are not working properly cause of Z80 CPU running slower than original MSX speed.

This Z80 CPU card runs 2.045Mhz  so, if games used a S/W loop delay, it would be a slower than Original Game speed. But, Many of games hard to feel the slowness. Maybe interrupt driven used for delay on the games. 

This is good approach and helpful even less or faster CPU system.

And now, I'm tuning it to make better.

Keep watch it How much could I approach for the MSX computer.

Thanks

I've tested below ROM file.

It works fine.

Mostly my favorite games.

I didn't test all games, just some what I liked.

Not all of games works but, many of games could run on the My Z80 card.

This card isn't for running games but, for MSX enjoy.

Hence, I will start for Keyboard emulation for MSX BASIC and other purpose.

Thanks

It start to run MSX Game as the attachment.

Having trouble to watch the video?

Please try here. 

https://youtu.be/ayVJRWHw2DU

Left monitor is for MSX system, Right one is for APPLE IIe.

Now It need two monitors but, I will combine the Video signal hence only need one monitor.

I used SD DISK HDD mode to load MSX BIOS and GAME ROM data into the Z80 Board.

And easy to load ROMBIOS of MSX and Image file of GAME ROM.

The Z80 board have 512KB Internal RAM and Main BIOS RAM area shared with APPLE II main memory.

Other Memory area can remap to 1000H-4FFFH for APPLE II access.

So the results bring easy handling by APPLE II.

It also act as the Softcard. (The Last movie parts) and working properly.

This is a Joypad for MSX Game.

But, I'm considering if it possible to use APPLE II keyboard to Joypad emulation.

Anyway, I will keep going to complete it for me.

Thank you very much.

Ian Kim

Z80 card run the MSX BASIC.

But, Still I have to do some more to support SLOT concept of MSX system.

And Keyboard and PSG(Sound chip).

I'm working for the SLOT memory but, It is hard to do now. cause there is no easy memory space for MSX.

Hence I decide to add one SRAM for MSX system.

It  become complex than I expected cause the SLOT memory space really required to run GAME of MSX.

And the SLOT memories having overlapped address on each SLOTs.

So, I'm having difficulties of this.

Anyway I will try to implement this SLOT for my Z80 Card and want to see the running MSX in my APPLE //e.

Thanks

Ian Kim