MFX with a difference

[gunrock]

* did you notce the non standard roms on the MTX ?

I did not. That photo was too indistinct and my eyes grow dim...

[Dave]

my eyes grow dim...

Did your head grow heavy too?

Did you have to stop for the night ?

[Martin A]

* did you notce the non standard roms on the MTX ?

I did not. That photo was too indistinct and my eyes grow dim...

The bright yellow labels are a bit subtle I guess ....

[1024MAK]

To be fair, on some issue boards, it's not that hard to rewire them to use EPROM chips...

Mark

[gunrock]

Did your head grow heavy too?

Did you have to stop for the night ?

Actually, I was more thinking of the Boy Scout/Army song 'The Quartermaster's Store':

My eyes are dim, I cannot see
I left my specs in the WC

[gunrock]

The bright yellow labels are a bit subtle I guess ....

True, but you mad tinkerers stick labels on anything and everything

[gunrock]

And why look at a different FPGA board?

Down to me I’m afraid . . . . .

I’ve had lots of problems with procuring the Cyclone Ii boards. There were shortages on the back of the Covid thing, but availability is improving. The biggest issue though is the variable quality of the boards from the Chinese vendors. Many of them have problems - mainly down to poor quality soldering of the FPGA onto the PCB.

I guess that is the double-edged sword of using dev boards and other ready built modules in your design; on the one hand you greatly speed up development, prototyping and reduce time to market - on the other, you often have a built-in obsolescence that can be hard to gauge.

This is the long-term problem with the MiSTer, one day Intel will no longer supply that dev board. It has also happened with just the FPGA chip and the semi-recent glut in scarcity - both the Ultimate 1541 disk drive emulator for the C64 and the F18A TMS 9918 VDP replacement have needed redesigns to use a new FPGA that is available for reasonable prices. In the case of the F18A, I see people have been using the Tang Nano dev board instead https://github.com/lfantoniosi/tn_vdp which is on the Chinese Tang Nano chip and readily available from AliXpress and such.

Hope something else suitable comes along or you manage to work out the power/noise issues.

[Martin A]

The bright yellow labels are a bit subtle I guess ....

True, but you mad tinkerers stick labels on anything and everything

[has a quick check of the Dev MTX] There's only 6 labled chips:
The 3 system ROMs
The motherboard PAL replacement, currently the MTX500 GAL is fitted, there's a MTX512 version too.
The MFX GAL, that has the 512K standard version fitted, there's a 384K version for Magrom compatibility testing.
The MFX rom, currently build 167, there'a January update rom too.

[gunrock]

[has a quick check of the Dev MTX] There's only 6 labled chips:
The 3 system ROMs
The motherboard PAL replacement, currently the MTX500 GAL is fitted, there's a MTX512 version too.
The MFX GAL, that has the 512K standard version fitted, there's a 384K version for Magrom compatibility testing.
The MFX rom, currently build 167, there'a January update rom too.

That's what I mean, Martin, you have custom ROMs, custom GALs, etc. and that's just the base Memotech hardware itself! Let alone what other Frankenstein alterations and open heart surgery that's occurring on the add-ons that you chaps have built.

I'm in awe of what you, Dave and Bill concoct in your Engineer's coven.

[Martin A]

Well....

I wanted to post a picture of the next generation MFX test board to Facebook. Unfortunately it seems to have entered a black hole somewhere!

So, apart from the colour there's a few other differences from the standard green board to spot.

The green boards in the photo will be off to Dave sometine soon, once I've finished the rest of the current batch of boards.

The black one is mine to "play" with .