Looking for info about this board installed on top of Xellent30

[hyrulebr]

Hi

My XVI came with a Xellent30 pc00066X and where was supposed to be the X68030 processor came another board with a processor (the x68030 I think but I can't take off the heatsink), some memory chip () and perhaps a co-processor? (again I can't see it too much glue used). As you can see in the Xellent board below already there is the original X68000 processor and the co-processor 6882.

Anyone knows what board is it?

Board installed in top of Xellent30


Some pics of the additional board alone






some pics of Xellent30 without the additional processor board






Xellent30  Model PC00066X



fullsize pics:
https://imgur.com/a/W5TRe

[repoMan]

Oh, you lucky man!, it's a rare piece of hardware, a MK-HM16 "high memory" board. I'm not 100% sure of all this info but it must have 16MB extra RAM onboard and a new full MC68030 including MMU. The second dissipator covers a Xilinx chip, no more surprises here.

[hyrulebr]

Oh, you lucky man!....

Nice to know, but I exchange it for my computer working properly...

High memory can only be used by X68030, right?

[repoMan]

I've no details about how to use it, probably it works as a RAM disk; but having a MMU must give it very powerful banking capabilities. Don't regret, I best prefer a working machine than a piece of collector's hardware, who wants more than 12MB?
Btw, this board is designed to be on top of Xellent30 accelerators; so it can be used in standard X68K machines, not only in the X68030.

[neko68k]

High memory can be used from the command line with some particular command I can't remember. I don't recall if it needs some particular software either. Basically you do something like 'loadhigh foo.x' and it will run it in the extra memory. It's kinda useless if you have 12MB already unless you plan on using NetBSD which also requires the MMU capable 030.

[hyrulebr]

High memory can be used from the command line with some particular command I can't remember. I don't recall if it needs some particular software either. Basically you do something like 'loadhigh foo.x' and it will run it in the extra memory. It's kinda useless if you have 12MB already unless you plan on using NetBSD which also requires the MMU capable 030.

Hi thanks for the info.  I found this page with the program to use the high memory:

http://retropc.net/x68000/person/watanabe_eisuke.htm

I'll try it latter. But what I need is a program to use these 16MB instead of (faulty) onboard memory...

[repoMan]

I think that without additional hardware is not possible. If I'm not wrong the 040Excel could map their 16MB over the onboard 12MB; but I don't have details if this is a hack or it offers 100% compatibility...

[neko68k]

You can't use external memory in place of GVRAM, TVRAM or PCG. If, indeed, your TVRAM is bad it'll have to be replaced :/

[repoMan]

And I must add that these SIP RAM modules are a real PITA to desolder and replace! 

[hyrulebr]

You can't use external memory in place of GVRAM, TVRAM or PCG. If, indeed, your TVRAM is bad it'll have to be replaced :/

Have you seen any document indicating where the TVRAM memory is physically?

And I must add that these SIP RAM modules are a real PITA to desolder and replace! 

My Techinican said the same!    

If I find where is the TVRAM he will try to replace it first.

[neko68k]

No, sorry. It's not really clear from the service manual. There should be two banks of 512k in the vicinity of the CRTC.