Sharp X68000 XVI inbound (tomorrow...)

[HigashiJun]

Thanks all !

I hope to rearrange my desk so the X68000 can have a better place.

[HigashiJun]

And here's what I will get tomorrow:

Xellent30.jpg (120.16 KiB) Viewed 113 times

An Xellent30 CPU accelerator board for my X68.

Really didn't expect to get one so soon and for a "bargain" price.

I will have to repair a broken pin and find an oscillator though, since the original one is missing.

[HigashiJun]

And here it is:

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2.JPG (455.13 KiB) Viewed 79 times

3.JPG (271.03 KiB) Viewed 79 times

As you can see, one pin is broken and has to be fixed.

The oscillator is missing and there is also a bodge wire from the oscillator output pin to the 68030 CLK pin, so I guess a trace must be cut somewhere. Not a big deal though and easy to repair.

I think the resistor is a pull-up to activate the MMU on the 68030 CPU, since the original one is a 68EC030 without MMU.

More to come later.

[HigashiJun]

Had time today to perform some repairs on the Xellent30:

1.JPG (357.39 KiB) Viewed 44 times

The broken pin is now fixed.

I'm still waiting for a 1.778 pitch 64 pin socket to reach me. It will prevent the repaired pin (and other) to bend and break. But damn, those are really hard to get nowadays.

I also decided to insulate the pull-down (and not pull-up) resistor as seen on the picture.

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The missing oscillator is now fitted.

The original one was a TTL oscillator I cannot find anymore. so it was replaced with a CMOS one.

I'm not an oscillator specialist, an guess this change won't affect the operation of the board.

(I really don't know what the bodge wire was for since no traces were cut at all).

Now I have to fit this new toy in my X68000, but it's another story.

[rubber_jonnie]

Very nice.

I'm assuming this board fits in place of the 68000? What sort of a boost does it give?

[HigashiJun]

@rubber_jonnie

Thanks !

Yes, you're right. The board fits in place of the 68000.

The 68000 is then installed on the Xellent30 so that during boot you can select with the keyboard whether you want to boot in 68000 mode or 68030 mode.

Fitted.jpg (75.29 KiB) Viewed 29 times

When 10MHz mode is selected on the X68000, the board works at 20 Mhz, and when 16MHz mode is on, the board then works at 33MHz.

To resume, you have access to the following speeds:

- X68000 at 10MHz (68000 mode) = 10 MHz
- X68000 at 16MHz (68000 mode) = 16 MHz
- X68000 at 10 MHz (68030 mode) = 20 MHz
- X68000 at 16 MHz (68030 mode) = 33 MHz

And with a full 68030 instead of the cheaper and less endowed 68EC030, you get MMU and access to High Memory.

The X68000 XVI becomes therefore more performant than the X68030.

BTW, nice new avatar you have !

[rubber_jonnie]

@rubber_jonnie

Thanks !

Yes, you're right. The board fits in place of the 68000.

The 68000 is then installed on the Xellent30 so that during boot you can select with the keyboard whether you want to boot in 68000 mode or 68030 mode.


Fitted.jpg


When 10MHz mode is selected on the X68000, the board works at 20 Mhz, and when 16MHz mode is on, the board then works at 33MHz.

To resume, you have access to the following speeds:

- X68000 at 10MHz (68000 mode) = 10 MHz
- X68000 at 16MHz (68000 mode) = 16 MHz
- X68000 at 10 MHz (68030 mode) = 20 MHz
- X68000 at 16 MHz (68030 mode) = 33 MHz

And with a full 68030 instead of the cheaper and less endowed 68EC030, you get MMU and access to High Memory.

The X68000 XVI becomes therefore more performant than the X68030.

BTW, nice new avatar you have !

Very well featured, looks like a great upgrade

The Avatar (Thanks for noticing ) is AI generated, if you look close it has a good feel of the old Atari 8 bit days Took me a while to get the size right though, there are restrictions on Avatar sizes

[HigashiJun]

The Avatar (Thanks for noticing ) is AI generated, if you look close it has a good feel of the old Atari 8 bit days Took me a while to get the size right though, there are restrictions on Avatar sizes

[chronicthehedgehog]

More quality repairs as always

[HigashiJun]

Thanks ! I try to do my best.