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Macintosh SE/30 logicboard recreation (thread revival)

daanvdl

Well-known member
Thank you craig1410 for updating your basket, and thanks Bolle for updating the board files!

My spare board has been badly damaged by battery acid, so I'm still looking for lots of parts before I can start.
That gives me plenty of time to prepare properly. Some ASIC's are really hard to find, like the 344S0602-A.

A general question; Is the CPU (MC68030RL16B) replaceable with a faster 68030 like MC68030RC50B? (i know the clock is still 16mhz).
These 50mhz CPU's are more commonly available.
 

olidlavoie

New member
Wooooo!!! Thank you so much for this project @Bolle!!! I went a bit different to other guys on this thread and transferred every single component from one board to the other, using my FR301 and a reflow station. Everything went together really well, just had some issues with the plcc solders at the end causing a simasimac, but some time spent with multimeter cleared it right up! (Photo was taken before the final clean and before i found the issues that stopped it from booting, including unsoldered and or shorted plcc legs and the backwards sony chip...)
IMG_20220126_120237.jpg
 
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ben68

Well-known member
Wooooo!!! Thank you so much for this project @Bolle!!! I went a bit different to other guys on this thread and transferred every single component from one board to the other, using my FR301 and a reflow station. Everything went together really well, just had some issues with the plcc solders at the end causing a simasimac, but some time spent with multimeter cleared it right up! (Photo was taken before the final clean and before i found the issues that stopped it from booting, including unsoldered and or shorted plcc legs and the backwards sony chip...)
View attachment 38095
This is gorgeous
 

CC_333

Well-known member
I noticed the four pads up by the ROM SIMM where the test pads are on original boards. I presume these are for those who wish to solder the ROM chips directly onboard to leave the slot open for... something?

With an onboard ROM, will the slot even work? Is there some way to select which one to use, as in other machines with a similar setup (such as the IIsi, to name one).

This is gorgeous
I agree! All that needs to be done is to create matching purple RAM and ROM SIMMs to complete the look!

c
 

Bolle

Well-known member
With an onboard ROM, will the slot even work? Is there some way to select which one to use, as in other machines with a similar setup (such as the IIsi, to name one).
When fitting PLCC sockets onto those 4 pads they will block the space where you'd install a SIMM socket and vice versa so you can't accidentally have two sets of ROMs installed at the same time.
 

craig1410

Well-known member
Wooooo!!! Thank you so much for this project @Bolle!!! I went a bit different to other guys on this thread and transferred every single component from one board to the other, using my FR301 and a reflow station. Everything went together really well, just had some issues with the plcc solders at the end causing a simasimac, but some time spent with multimeter cleared it right up! (Photo was taken before the final clean and before i found the issues that stopped it from booting, including unsoldered and or shorted plcc legs and the backwards sony chip...)
View attachment 38095

Nice work! Enjoy!
 

daanvdl

Well-known member
@here: Can the ZILOG Z8530 (4Mhz) be replaced by a 6Mhz or 8Mhz (or even 16Mhz) ZILOG Z8530?
(AM85C30-16JC AM85C30-8JC AM8530H-8JC etc.)
 

craig1410

Well-known member
@here: Can the ZILOG Z8530 (4Mhz) be replaced by a 6Mhz or 8Mhz (or even 16Mhz) ZILOG Z8530?
(AM85C30-16JC AM85C30-8JC AM8530H-8JC etc.)
That's a good question and I'm not 100% sure of the answer but the chip part number on my board is a Z0853006VSG which I think means it's a 6MHz part. You can get a pretty detailed data sheet from here: https://www.digchip.com/datasheets/parts/datasheet/542/Z8530-pdf.php so you should be able to check min and max timing specs so work out what is supported.

From the SE/30 schematics the PCLK signal on the 8530 seems to be driven by the C3M signal which I think is a 3MHz clock derived from the main system clock. It's probably not exactly 3MHz but will be 3.xyz MHz. So, given that this is not 4, 6 or 8MHz, I'd hazard a guess that the clock frequency rating of the 8530 is more of a *maximum* than an exact spec. Most likely the parts are all made the same way but during testing some are found to support higher speeds and are binned accordingly.

In the data sheet it says about the PCLK signal that:
PCLK. Clock (input). This is the master SCC clock used to synchronize internal signals. PCLK is a TTL level signal. PCLK is not required to have any phase relationship with the master system clock.​
So again this suggests to me that this clock is purely for internal purposes and I expect the dividers which are set up during configuration of the chip will be set to assume this 3.xyz MHz input clock and will produce the expected serial baud rates like 115200, 57600.

That all said, the lower speed parts are probably cheaper than the higher speed parts but if availability of the 6MHz part is limited then I'd guess that the 8MHz one would probably work fine. It might not be a good idea to go as low as a 4MHz part if the clock speed is in excess of 3MHz especially if my board is typical and 6MHz parts are fitted as standard.
 

daanvdl

Well-known member
Thank you so much Craig,

I think this answered all my questions regarding the Z8530.
Both my original boards do have the Z0853004VSG (4mhz) version soldered on.
The fact that you have the Z0853006VSG in place tells me that this should not be any problem:)

Thanks again for your support!
 

craig1410

Well-known member
@daanvdl after seeing your reply I went back to some old photos I took of my boards before I commenced repairs and actually mine also had the 4MHz parts installed originally. But it is definitely the 6MHz part which is installed and fully working on my "reloaded" board and I can confirm it passes all the Snooper serial port tests.

I also have a 6MHz part installed on my other SE/30 board because I was trying to debug a serial port issue but the issue was not resolved by replacing the 8530. More specifically the issue is the same with the new 6MHz chip as it was with the old 4MHz chip.

So I think this still suggests that at least the 6MHz chip can be used in place of a 4MHz part but I wanted to let you know that my boards were actually 4MHz chips originally to avoid misleading you. Apologies for the confusion.
 

cheesestraws

Well-known member
As far as I know, that frequency is just a maximum rating, and replacing it with a higher-frequency part isn't going to cause issues at all.

Another data point for you: in other Macs, there were experiments recently in swapping the SCC for a higher rated part to try to allow overclocking of the system as a whole. I can't remember whether it helped with the overclocking, but it worked at "normal" clock fine.
 

daanvdl

Well-known member
Thanks again Craig. I did order a few 6Mhz Zilogs!
I programmed the provided JEDEC GAL's and confirmed they are working, thanks Bolle for reverse engineering them!
I cant wait to start, but I just need a few last parts before the main job can be done:-(

Y3 16.9344 MHz
Y1 32.768kHz

I do see several radial crystals on the Mouser websites which matches the frequency, but they differ in capacity and resistants, so am not sure which one to choose.
(It looks like there is also space on the board for a SMD crystal instead of radial design)
Can somebody provide me Mouser links or can confirm a specific type will actually do the job?

Beside the crystals;
Part 344S0602-A and 342S0440-B are my main concern..
I did contact Utsource and many others, but it looks like nobody has them:-(
Any suggestions on those?IMG_1991.png
 
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daanvdl

Well-known member
Hi Scott,
The SE do have a DIP18 ADB controller, while the SE/30 do have a PLCC type controller. A PIC16CR54 will not do the trick in our case:-(
Maybe a ATF16V would do, but nobody confirmed the reversed engineered code do work..
 

Scott Squires

Well-known member
Oh, right. I would be surprised if they weren't compatible, but someone would have to make an adapter or a board revision with a SSOP/SOIC footprint.

And if you manage to program an ATF16V with PIC code, I will be extremely impressed. 😄
 

daanvdl

Well-known member
@Bolle: I ordered a few boards on JLCPCB. They say there is an issue while making them;
"As shown below, it seems that these slots are connected to copper pour and will cause short circuit. Shall we make them isolate to proceed??"

I looks like these slots are at the audiojack and ADB ports. Are they intended connected to the copper pour?

For the ADB ports: It looks like that is the pin on the ADB connector at the edge of the board which is connected to ground on my damaged PCB.
For the audiojack: It looks like that is pin 3 on the SJ1-3535NG connector which is the ring on the jack and should be ground.
7179c7831f8f40ff9b74bb0321be49c4.png
f59658541c224c948213495e8f01c107.png
 
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daanvdl

Well-known member
After some more measuring i came to the following conclusion:
ADB ports: This specific 'problem' slot is connected to ground, together with the 2 neighbor pins. This pin should be a problem to isolate.
Audio Jack: Pin 1 is ground. Pin 3 is the 'problem' slot. Pin 3 and 5 are internally connected to each other in the connnector. . Pin 5 is connected to R1, so this should be a problem to isolate either.
 
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