GreenBar0n
Well-known member
The Pin Matrix Data chart insists pin N is the last pin of UK8, the CPU. The Pin Matrix chart lines up correctly if you ignore there are only (13) pins, and pretend the last one is N.
Macintosh SE/30 M5119 - Restoration
- Thread starter GreenBar0n
- Start date
GreenBar0n
Well-known member
Made it through the Data Pin Matrix, all pins and continuity check out.
Need to put this back together, and start looking for reset and clock signals.
Do have an ATX extension cable.
https://www.amazon.com/dp/B07L88HJ9X
Need to put this back together, and start looking for reset and clock signals.
Do have an ATX extension cable.
https://www.amazon.com/dp/B07L88HJ9X
GreenBar0n
Well-known member
At least I didn't make it any worse.
Need to check the Reset and Clock lines today.
Is there a way to check the ROM without a spare or replacement?
Need to check the Reset and Clock lines today.
Is there a way to check the ROM without a spare or replacement?
GreenBar0n
Well-known member
Rather than try to visually inspect this board for broken traces, it's time for a diagnostics program.
In this episode of Adrian's Digital Basement: he uses a modem cable (8-pin to 25-pin), converted with Laplink cables, to connect to a PC's DB9 port with Terra Term - in order to obtain error codes for a pre-ROM boot (simasimac SE/30 board).
With the Poor-Man's Tech Step, he's able to decipher the error code, and locate the broken chip/trace with the info obtained.
Rather than going through all those conversions of cable's, would it be possible to use just an 8-pin DIN, that goes straight to DB9, such as this cable?
In this episode of Adrian's Digital Basement: he uses a modem cable (8-pin to 25-pin), converted with Laplink cables, to connect to a PC's DB9 port with Terra Term - in order to obtain error codes for a pre-ROM boot (simasimac SE/30 board).
With the Poor-Man's Tech Step, he's able to decipher the error code, and locate the broken chip/trace with the info obtained.
Rather than going through all those conversions of cable's, would it be possible to use just an 8-pin DIN, that goes straight to DB9, such as this cable?
6ft APPLE IIGS Printer Cable Mini DIN 8 Male to DB9 Female - Gray | eBay
The APPLE IIGS Printer Cable Mini DIN 8 Male to DB9 Female is a reliable and efficient connection solution. With its Mini DIN 8 Male and DB9 Female connectors, it seamlessly connects your APPLE IIGS computer to supported printers. This cable is designed to deliver a stable and high-speed data...
www.ebay.com
croissantking
Well-known member
I just used a standard Apple serial cable (with DIN-8 on both ends) and hooked it up to my Macintosh IIci running Zterm.
GreenBar0n
Well-known member
I have a good SE instead of a IIci, would an SE and Zterm work, with the same cable you used?
croissantking
Well-known member
Probably, I don’t have any 68000 Macs but I’m sure they could handle a bit of terminal emulation
GreenBar0n
Well-known member
I have plenty of good DB9 capable PC's here. Just can't determine if that 8-pin Apple printer cable would line up with the correct DB9 output, or RS-232 COM port input. A null modem adapter might be necessary to cross the Tx and Rx between terminals, in order to get that to work.
I can confirm this works. I believe Apple printer cables are nulled by default. I used one to connect my Macintosh Plus with Zterm to my IIfx to access the diagnostics mode a few years ago.
The problem that I had wasn’t the connection— there is virtually no documentation that I could find on the actual diagnostics commands and the responses. Apparently different ROMs have somewhat different command and reply sets. I could never make much sense of what information I was getting.
But, it does work.
The problem that I had wasn’t the connection— there is virtually no documentation that I could find on the actual diagnostics commands and the responses. Apparently different ROMs have somewhat different command and reply sets. I could never make much sense of what information I was getting.
But, it does work.
GreenBar0n
Well-known member
Great to hear that cable works, I'll get the 8-pin DIN to DB9. Thanks!
Here's the spreadsheet Adrian prepared with the commands for terminal access to the pre-ROM boot:
https://docs.google.com/spreadsheet...LH6ruCiAVE/edit?gid=1499087781#gid=1499087781
He also includes assembly code that tests the video ram. Going to get that cable and see what I can find.
Here's the spreadsheet Adrian prepared with the commands for terminal access to the pre-ROM boot:
https://docs.google.com/spreadsheet...LH6ruCiAVE/edit?gid=1499087781#gid=1499087781
He also includes assembly code that tests the video ram. Going to get that cable and see what I can find.
GreenBar0n
Well-known member
You're welcome! And thanks to Adrian for putting the spreadsheet together.
Found an 8-pin to DB9 that claims to be RS-232. Already have a USB to DB9/COM port that will connect to this.
https://www.ebay.com/itm/184211248546
The cable was shipped this morning, should have it by this weekend.
Found an 8-pin to DB9 that claims to be RS-232. Already have a USB to DB9/COM port that will connect to this.
https://www.ebay.com/itm/184211248546
The cable was shipped this morning, should have it by this weekend.
I’ve done the poor man’s tech step on my SE/30 using DB9 to DIN-8 cable I made for use with ADTPro on my Apple IIGS. Here is the pinout:
It’s wired as a null modem. I used an old DIN8 to DIN8 cable, cut one end off and attached a DB9 breakout board:
It’s wired as a null modem. I used an old DIN8 to DIN8 cable, cut one end off and attached a DB9 breakout board:
Attachments
GreenBar0n
Well-known member
Nice work! What are you using on the DB9 end to talk to the SE/30 board with? Have you been able to retrieve any useful info from it?
Diagnostic Mode - mac68k - Confluence
I was running CoolTerm on a 2018 mac mini running macOS Sequoia
Using this USB to DB9 adapter - I like it because its 6ft long, so between the adatper and the null modem cable I could have the SE/30 on bench across room
Amazon.com: UGREEN USB 2.0 to RS232 DB9 Serial Cable Male A Converter Adapter with FTDI Chipset for Windows 10 8.1 8 7 Vista Linux and Mac OS X 10.6 and Above 6FT : Electronics
Buy UGREEN USB 2.0 to RS232 DB9 Serial Cable Male A Converter Adapter with FTDI Chipset for Windows 10 8.1 8 7 Vista Linux and Mac OS X 10.6 and Above 6FT: Cables & Interconnects - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
I see its no longer for sale, but other 6ft adapters exist.
I was able to execute code on the CPU using TechStep commands - that made me focus on video circuit, it ended up being UG8. I wrote about my troubleshooting here: https://68kmla.org/bb/index.php?thr...king-to-no-video-does-chime-on-startup.48851/
GreenBar0n
Well-known member
I've got to try to fix this stock board, if all else fails the Reloaded board is a great option.
Gives me some hope this can be a useful tool. Thanks.
GreenBar0n
Well-known member
It took forever to get that din-8 to DB9 cable from ebay.
When I connect it between a PC/USB COM port and the SE/30 serial port next to the audio output jack, I get no flashing cursor or keyboard input in Putty or TeraTerm, both set to 9600, 8, 2 stop bits, no parity, no flow control. Have a null modem adapter on the way tomorrow, to see if this is what the problem is and why I get no cursor.
When I connect it between a PC/USB COM port and the SE/30 serial port next to the audio output jack, I get no flashing cursor or keyboard input in Putty or TeraTerm, both set to 9600, 8, 2 stop bits, no parity, no flow control. Have a null modem adapter on the way tomorrow, to see if this is what the problem is and why I get no cursor.
