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I'm not quite following? 8 1M x 4 bit chips makes 4MB

They are 1Mx4 ones, essentially the equivalent of 4 2 chip simms, I do also have some 1M x 16 chips on order to experiment with as it would allow just two chips to be used

Revised boards have been sent off to JLC :)

I swear you have clones on just about every accelerator known to man on the go :)

Logicboard wise the IWM is the only part left, and that's only needed if you want to use a floppy drive. These boards are designed to use a pldSCHWIM to bypass the need to have a IWM installed and can be built entirely without and original parts

That case uses a pico PSU (you can see the module plugged in to the bottom left corner of the board) which is fine here, the hole thing with a BlueSCSI connected only draws about 10w

Yes it's a very small form factor ITX case, there isn't any provision in this one for expansion cards but that's not really a issue here as the Performa clone would lay flat on the board anyway (and I was trying to build a really small system :) )

So what's next? The boards need a little tweaking to resolve the issues noted above, once this is done I'll get another run of test PCB's made and tested and then post the designs up on github I also intend to make a Port Riser board with connections for a original keyboard and mouse should...

So with the board booting it's time to look at the I/O First to be tackled was the SCSI connectors, these where soldered on and the board booted Mac OS 7.1 from my BlueSCSI just fine. That's good! it's nice when stuff just works :) Except..... Apparently I used the wrong footprint.... Oh well...

Build is looking good! Just waiting for my BlueSCSI PCB's so I can finish it off

So, As mentioned above the board is now booting and working just fine but how did we get here? When the board was initially tested after assembly it did nothing at all. No chime and no video. Though frustrating this is kind of what I expected, the scan of the apple schematics we have is not...

That's more or less the last thing I need to test, Just have to go through my scrap boards and find somewhere I can steal a 26LS30 and 26LS32 from but given the mouse works fine (which requires the SCC to work) I expect they will work just fine :) Yep, -12V is used for the audio and is...

I have been a little slow updating this thread but testing and tweaking has continued in the background, I'll do a full write up over the weekend but I'll leave this photo here in the meantime; 7.1 Boots from SCSI just fine :)

It's late and I'm not doing a full write-up tonight, but I'll just leave these here (excuse the potato video, it's that or a massive file and I cba with trying to compress it right now)

That'll be tomorrows job :) All the non programmables (and the ROM) are soldered down, will get all the PAL's programmed and installed tomorrow. Also still waiting for a pico to arrive as my spare one is AWOL

PCB's are here!

At the moment just 5 to see if they work, I may do a larger run later though (It will also be open source so you will be able to make your own too :) )

Boards have been sent off to JLC, hopefully I should have them in hand by the end of next week :)

It may actually be possible to build one of these with more TH parts, Probably not fully TH but there might just be enough space to squeeze in DIP parts for all the logic and PAL's and maybe the SCSI controller, ROM / VIA / SCC would have to stay as SMT parts though as there just isn't the space...

MLB is done! Just need to draw up the riser with the keyboard / mouse / serial ports on it