demik

Yeah Umax always had their logo printed. They also had doors on most models. Looks like a Motorola.

Good job again. I think the NCR ship is repleacable but the Zilog Z53C8003VSG which is still in production. Pins looks compatible ! They might be a compatible SSC still produced too. Can you give us the PN ? Should be a 8530 IIRC. I will take a look Is the BBU compatible with the SE one ? Edit: found it Z0853004AVSC. Z85C3008VSG looks pin compatible - SCSI: https://www.mouser.fr/ProductDetail/ZiLOG/Z53C8003VSG/?qs=FsLZlD%2B%2Bd9cJEZW2nIhyXQ%3D%3D - SCC: https://www.mouser.fr/ProductDetail/ZiLOG/Z85C3008VSG/?qs=z96q%2FFFR6qb6cf17DanQqQ%3D%3D

Question about a cache like this : is it cache useful if you pair a 68000 with a ram fast enough so that every memory access is zero wait states ?

G4 ZIF in a beige G3 works. You may have to change de CPU Ratio due tu bus speed difference but it works. PowerLogic and others used to make G4 ZIF upgrades for Beiges. Got a PowerLogic G4 on my G3 MT. Stock regulator board IIRC

Thanks ! I've already got two on the way. But the thing is on the MacSnap, one PAL has an output used as an input and the other one has like 14 inputs. Kai's boards only works with 16L8 PALs (8 inputs only) I will need to build a custom PAL dumper for this... And yeah it's the only thing that's is difficult really Thanks both of you for your feedback. I've looked around SCSI specs this week-end and choose this set up : - the board will provide both active termination and termination power for SCSI2SD and alike. Each one can be disabled if needed

Didn't think of that. I will do a dummy PCB to check this, thanks ! Thanks ! I'm missing the PALs equations for now, and I'm not as skilled with PALs as some other folks around there. Anyway, I made a few changes to the PCB: - There is now Internal terminaison power (for SCSI2SD) - I put a 26 pin IDC header wired to use a LPT header. They are avaible on eBay or Aliexpress for like $3 or $4 bucks. The only thing missing would be the plastic part. Will get back to you when everything is working. it makes sense, thanks. Would that

Thanks ! I got two IIcx, one socketed, one soldered. The socketed one isn't starting yet (recap done), Don't want to mess with the working one, I will keep your offer in mind. Good job anyway !

Ok, some progress: - after a few lectures, 128k ROM means MacPlus ROM. - double checked the PALs and there is no clock line, so 90% sure they are combinational. - got the Z53C80 - made "new" ROMs using AT27C512R, they works fine : https://www.mouser.fr/ProductDetail/Microchip-Technology-Atmel/AT27C512R-70PU/?qs=lURXKZrvvXfxaNMm462qBA%3D%3D - since one of the PALs got 14 inputs, I need a logic analyser or two and some other stuff. Bough two of them, waiting for delivery. - everything is on GitHub now : https://github.com/demik/oldworld/tree/master/EDA/MacSn

Thanks ! Looks only simple traces to create a PDS slot. Should be straightforward to replicate

A somewhat more complete version is available here : http://mess.redump.net/mess/driver_info/mac_technical_notes?s[]=mac&s[]=technical

Very nice ! How does this fit an Iicx ? Do you need another extra board ?

Ok thanks, I will buy a set to test with my 512ke boards

Did you test the RTC with the ATTiny85 replacement ? If not, can I test it on a stock 512ke board ? They looks similar

Jumping in there but you need to modify at leat : - Chip selects (BMUs/BBUs/CAS*) - SCSI is in the low range too (Around 5 MB) - ROM - ASICs (the internal video card and sound card comes to mind) I'm not sure if the SCSI Manager for example would work with a "non-standard" offset. It would be easier to put a Macintosh Portable motherboard inside an SE case

Looks like an UK layout or "English International". Very similar to the US one, except for the "enter" key and a few other ones https://support.apple.com/en-us/HT201794