Neru💤
@gateta.systems
💾 Me gustan los ordenadores y hacer circuitos. ⌨️ Retrocomputing. ❤️ @kd0082.bsky.social.
Managed to get Mac OS 8.1 ISO 'burned' into a 640MB MO disk which is bootable. First initialize the MO, then locate HFS partition in ISO, and copy its contents to the MO's HFS partition offset.
Used 7-Zip and HxD for it.
Used 7-Zip and HxD for it.
February 18, 2026 at 11:29 PM
Managed to get Mac OS 8.1 ISO 'burned' into a 640MB MO disk which is bootable. First initialize the MO, then locate HFS partition in ISO, and copy its contents to the MO's HFS partition offset.
Used 7-Zip and HxD for it.
Used 7-Zip and HxD for it.
I just realized that the first photo of the Macintosh’s back shows the ADB port. This is the correct one. A PhoneNet adapter is used on the Printer port. Only the 2 outer wires 2 and 5 are used on the RJ-11 cable. At the other end I use a MAX485 to decode the differential signal to a Pico GPIO.
February 18, 2026 at 7:57 AM
I just realized that the first photo of the Macintosh’s back shows the ADB port. This is the correct one. A PhoneNet adapter is used on the Printer port. Only the 2 outer wires 2 and 5 are used on the RJ-11 cable. At the other end I use a MAX485 to decode the differential signal to a Pico GPIO.
Cooking LocalTalk on Pico 2W.
February 18, 2026 at 7:50 AM
Cooking LocalTalk on Pico 2W.
Both tested with 0 slow sectors, yay.
Seagate HDD finished a bit earlier than Hitachi HDD and was 48°C. Hitachi was 52°C. They both weigh ~620g, Seagate 10g more than Hitachi.
Seagate HDD finished a bit earlier than Hitachi HDD and was 48°C. Hitachi was 52°C. They both weigh ~620g, Seagate 10g more than Hitachi.
February 17, 2026 at 11:51 AM
Both tested with 0 slow sectors, yay.
Seagate HDD finished a bit earlier than Hitachi HDD and was 48°C. Hitachi was 52°C. They both weigh ~620g, Seagate 10g more than Hitachi.
Seagate HDD finished a bit earlier than Hitachi HDD and was 48°C. Hitachi was 52°C. They both weigh ~620g, Seagate 10g more than Hitachi.
Got a couple of 500 GB IDE HDDs for cheap.
I always check them in MHDD.
Don't trust SMART before a full surface scan.
I always check them in MHDD.
Don't trust SMART before a full surface scan.
February 17, 2026 at 7:50 AM
Got a couple of 500 GB IDE HDDs for cheap.
I always check them in MHDD.
Don't trust SMART before a full surface scan.
I always check them in MHDD.
Don't trust SMART before a full surface scan.
Recapped and cleaned. Some SMD ICs resoldered.
February 8, 2026 at 5:18 PM
Recapped and cleaned. Some SMD ICs resoldered.
Analog board cleaned, dried, installed, and tested. It's now logic board turn.
February 8, 2026 at 2:22 PM
Analog board cleaned, dried, installed, and tested. It's now logic board turn.
I guess it was a bad solder joint somewhere.
February 7, 2026 at 8:40 PM
I guess it was a bad solder joint somewhere.
It's just a guess since I can't measure it, but I do observe VCC worsen if CP4 area is cold and improve if CP4 area is warm. Testing reveals CP4 shouldn't be the issue. Main resistors measure OK. Maybe something is stealing power from that winding (red), or maybe DP4 is not giving enough power.
February 7, 2026 at 3:29 PM
It's just a guess since I can't measure it, but I do observe VCC worsen if CP4 area is cold and improve if CP4 area is warm. Testing reveals CP4 shouldn't be the issue. Main resistors measure OK. Maybe something is stealing power from that winding (red), or maybe DP4 is not giving enough power.
RP1 only provides like 4mA which is not enough to maintain TDA4605 switching, VCC needs power from an additional source. The TDA4605 starts switching, generating the secondary voltages, and generating a second VCC source, which comes from here highlighted in yellow. I hope I'm understanding this OK.
February 7, 2026 at 3:29 PM
RP1 only provides like 4mA which is not enough to maintain TDA4605 switching, VCC needs power from an additional source. The TDA4605 starts switching, generating the secondary voltages, and generating a second VCC source, which comes from here highlighted in yellow. I hope I'm understanding this OK.
The capacitor for TDA4605 VCC is CP4 (47uF) but it doesn't seem to be the issue.
Unfortunately I can't peek at stuff on the primary side since its not referenced to ground.
If I understand the schematic correctly, VCC is generated from half mains via 22k resistor RP1 for the Start-up current.
Unfortunately I can't peek at stuff on the primary side since its not referenced to ground.
If I understand the schematic correctly, VCC is generated from half mains via 22k resistor RP1 for the Start-up current.
February 7, 2026 at 3:29 PM
The capacitor for TDA4605 VCC is CP4 (47uF) but it doesn't seem to be the issue.
Unfortunately I can't peek at stuff on the primary side since its not referenced to ground.
If I understand the schematic correctly, VCC is generated from half mains via 22k resistor RP1 for the Start-up current.
Unfortunately I can't peek at stuff on the primary side since its not referenced to ground.
If I understand the schematic correctly, VCC is generated from half mains via 22k resistor RP1 for the Start-up current.
Got a Macintosh Classic II this week that needs recapping due to most of them leaking and the smell of these is terrible. But I'm happy to restore old computers.
February 5, 2026 at 8:13 PM
Got a Macintosh Classic II this week that needs recapping due to most of them leaking and the smell of these is terrible. But I'm happy to restore old computers.
Huge *I have no idea what I'm doing* moment but it's fixed.
February 2, 2026 at 6:33 PM
Huge *I have no idea what I'm doing* moment but it's fixed.
The picture in the quoted post is before replacing, this one is after replacing them. They looked fine but when tested their capacitance was low and one of them had low resistance. They felt very light.
February 2, 2026 at 4:54 PM
The picture in the quoted post is before replacing, this one is after replacing them. They looked fine but when tested their capacitance was low and one of them had low resistance. They felt very light.
@kd0082.bsky.social burned some CDs for her Sega Saturn with a slim USB LG DVD-RW but the console had trouble reading them. I burned some with the 5.25" IDE LG DVD-RW from the Pentium II PC and they worked.
The console PSU also had bad capacitors which wasn't helping:
bsky.app/profile/gate...
The console PSU also had bad capacitors which wasn't helping:
bsky.app/profile/gate...
February 2, 2026 at 4:38 PM
@kd0082.bsky.social burned some CDs for her Sega Saturn with a slim USB LG DVD-RW but the console had trouble reading them. I burned some with the 5.25" IDE LG DVD-RW from the Pentium II PC and they worked.
The console PSU also had bad capacitors which wasn't helping:
bsky.app/profile/gate...
The console PSU also had bad capacitors which wasn't helping:
bsky.app/profile/gate...
Just the next day the magneto optical drive broke. I found a replacement online but I'm not sure how to print it. I'll try PLA+ with supports and PETG as support interface.
February 2, 2026 at 1:22 PM
Just the next day the magneto optical drive broke. I found a replacement online but I'm not sure how to print it. I'll try PLA+ with supports and PETG as support interface.
This weekend I made this. It's a pain getting files to old Macs since they only have a floppy drive (1.44 MB). I put an unused SCSI magneto optical drive I had in a 3D printed case to use with old Macintosh. The DB-25 to IDC-50 wiring was difficult. I installed System 7.1 on a MO and it even boots.
February 1, 2026 at 11:23 PM
This weekend I made this. It's a pain getting files to old Macs since they only have a floppy drive (1.44 MB). I put an unused SCSI magneto optical drive I had in a 3D printed case to use with old Macintosh. The DB-25 to IDC-50 wiring was difficult. I installed System 7.1 on a MO and it even boots.
To continue using it until a replacement gear arrived, I decided to remove the motor. The floppy was working again, just needing to manually eject the disk with a paper clip. The next day it stopped working, making some weird sounds, and disks weren't spinning at all.
January 28, 2026 at 10:23 AM
To continue using it until a replacement gear arrived, I decided to remove the motor. The floppy was working again, just needing to manually eject the disk with a paper clip. The next day it stopped working, making some weird sounds, and disks weren't spinning at all.
Last weekend the floppy drive from wife's LC III stopped ejecting disks. A gear in the eject motor broke (common). Since the motor is attached to the tray and the gears wouldn't move, it was not possible to continue using it as the mechanism was seized.
January 28, 2026 at 10:23 AM
Last weekend the floppy drive from wife's LC III stopped ejecting disks. A gear in the eject motor broke (common). Since the motor is attached to the tray and the gears wouldn't move, it was not possible to continue using it as the mechanism was seized.
Quería enseñarle este tipo de canario a waifu. Todo normal hasta ver la sugerencia.
January 27, 2026 at 9:16 PM
Quería enseñarle este tipo de canario a waifu. Todo normal hasta ver la sugerencia.
Me ha sorprendido la velocidad de bajada de Endfield
January 27, 2026 at 1:23 PM
Me ha sorprendido la velocidad de bajada de Endfield
Spent the weeked recapping and cleaning a Macintosh LC III and a Macintosh LC 475.
January 25, 2026 at 9:33 PM
Spent the weeked recapping and cleaning a Macintosh LC III and a Macintosh LC 475.